Version 2.15.0-172.0.dev
Merge commit 'bdbb4baea5160ef3ecba97d5684e740c2e110382' into 'dev'
diff --git a/DEPS b/DEPS
index b279283..289ba32 100644
--- a/DEPS
+++ b/DEPS
@@ -139,7 +139,7 @@
"pool_rev": "7abe634002a1ba8a0928eded086062f1307ccfae",
"process_rev": "56ece43b53b64c63ae51ec184b76bd5360c28d0b",
"protobuf_rev": "c1eb6cb51af39ccbaa1a8e19349546586a5c8e31",
- "pub_rev": "a817863ee93241ff36fce6856c6d12fd8fde0907",
+ "pub_rev": "37d05928939b3100e7e55c3dff922651db1de1e1",
"pub_semver_rev": "a43ad72fb6b7869607581b5fedcb186d1e74276a",
"resource_rev": "6b79867d0becf5395e5819a75720963b8298e9a7",
"root_certificates_rev": "692f6d6488af68e0121317a9c2c9eb393eb0ee50",
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000..a341d38
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,3 @@
+## Reporting vulnerabilities
+To report potential vulnerabilities, please see our security policy on
+[https://dart.dev/security](https://dart.dev/security).
diff --git a/pkg/analyzer/lib/src/dart/constant/evaluation.dart b/pkg/analyzer/lib/src/dart/constant/evaluation.dart
index e26da9a..ac84337 100644
--- a/pkg/analyzer/lib/src/dart/constant/evaluation.dart
+++ b/pkg/analyzer/lib/src/dart/constant/evaluation.dart
@@ -514,8 +514,8 @@
var fieldValue = field.evaluationResult?.value;
// It is possible that the evaluation result is null.
- // This happens for example when we have duplicate fields.
- // class Test {final x = 1; final x = 2; const Test();}
+ // This happens for example when we have duplicate fields; for example:
+ // `class Test {final x = 1; final x = 2; const Test();}`.
if (fieldValue == null) {
continue;
}
@@ -1103,7 +1103,6 @@
return constructorTearoffResult;
} else {
var typeArguments = <DartType>[];
- var typeArgumentObjects = <DartObjectImpl>[];
for (var typeArgument in typeArgumentList.arguments) {
var object = typeArgument.accept(this);
if (object == null) {
@@ -1117,7 +1116,6 @@
// type arguments. Possibly change implementation based on
// canonicalization rules.
typeArguments.add(typeArgumentType);
- typeArgumentObjects.add(object);
}
// The result is already instantiated during resolution;
// [_dartObjectComputer.typeInstantiate] is unnecessary.
@@ -1125,7 +1123,7 @@
typeSystem,
node.typeOrThrow,
FunctionState(node.constructorName.staticElement,
- typeArguments: typeArgumentObjects),
+ typeArguments: typeArguments),
);
}
}
@@ -1150,7 +1148,6 @@
return functionResult;
} else {
var typeArguments = <DartType>[];
- var typeArgumentObjects = <DartObjectImpl>[];
for (var typeArgument in typeArgumentList.arguments) {
var object = typeArgument.accept(this);
if (object == null) {
@@ -1164,10 +1161,8 @@
// type arguments. Possibly change implementation based on
// canonicalization rules.
typeArguments.add(typeArgumentType);
- typeArgumentObjects.add(object);
}
- return _dartObjectComputer.typeInstantiate(
- functionResult, typeArguments, typeArgumentObjects);
+ return _dartObjectComputer.typeInstantiate(functionResult, typeArguments);
}
}
@@ -1459,7 +1454,7 @@
DartObjectImpl? visitSimpleIdentifier(SimpleIdentifier node) {
var value = _lexicalEnvironment?[node.name];
if (value != null) {
- return value;
+ return _instantiateFunctionType(node, value);
}
return _getConstantValue(node, node.staticElement);
@@ -1681,9 +1676,13 @@
// and errors for other constant expressions. In either case we have
// already computed values of all dependencies first (or detect a cycle),
// so the value has already been computed and we can just return it.
- var value = variableElement.evaluationResult;
- if (variableElement.isConst && value != null) {
- return value.value;
+ var result = variableElement.evaluationResult;
+ if (variableElement.isConst && result != null) {
+ var value = result.value;
+ if (value == null) {
+ return value;
+ }
+ return _instantiateFunctionType(node, value);
}
} else if (variableElement is ConstructorElement) {
return DartObjectImpl(
@@ -1746,6 +1745,33 @@
return null;
}
+ /// If the type of [value] is a generic [FunctionType], and [node] is a
+ /// [SimpleIdentifier] with tear-off type argument types, returns [value]
+ /// type-instantiated with those [node]'s tear-off type argument types,
+ /// otherwise returns [value].
+ DartObjectImpl? _instantiateFunctionType(
+ Expression node, DartObjectImpl value) {
+ if (node is! SimpleIdentifier) {
+ return value;
+ }
+ var functionElement = value.toFunctionValue();
+ if (functionElement is! ExecutableElement) {
+ return value;
+ }
+ var valueType = functionElement.type;
+ if (valueType.typeFormals.isNotEmpty) {
+ var tearOffTypeArgumentTypes = node.tearOffTypeArgumentTypes;
+ if (tearOffTypeArgumentTypes != null &&
+ tearOffTypeArgumentTypes.isNotEmpty) {
+ var instantiatedType =
+ functionElement.type.instantiate(tearOffTypeArgumentTypes);
+ return value.typeInstantiate(
+ typeSystem, instantiatedType, tearOffTypeArgumentTypes);
+ }
+ }
+ return value;
+ }
+
/// Return `true` if the given [targetResult] represents a string and the
/// [identifier] is "length".
bool _isStringLength(
@@ -2186,7 +2212,6 @@
DartObjectImpl? typeInstantiate(
DartObjectImpl function,
List<DartType> typeArguments,
- List<DartObjectImpl> typeArgumentObjects,
) {
var rawType = function.type;
if (rawType is FunctionType) {
@@ -2194,7 +2219,7 @@
return null;
}
var type = rawType.instantiate(typeArguments);
- return function.typeInstantiate(_typeSystem, type, typeArgumentObjects);
+ return function.typeInstantiate(_typeSystem, type, typeArguments);
} else {
return null;
}
diff --git a/pkg/analyzer/lib/src/dart/constant/value.dart b/pkg/analyzer/lib/src/dart/constant/value.dart
index 80943a1..6d3ec97 100644
--- a/pkg/analyzer/lib/src/dart/constant/value.dart
+++ b/pkg/analyzer/lib/src/dart/constant/value.dart
@@ -210,8 +210,7 @@
bool get isUserDefinedObject => _state is GenericState;
@visibleForTesting
- List<DartObjectImpl>? get typeArguments =>
- (_state as FunctionState)._typeArguments;
+ List<DartType>? get typeArguments => (_state as FunctionState)._typeArguments;
@override
bool operator ==(Object object) {
@@ -921,10 +920,13 @@
return null;
}
+ /// Return the result of type-instantiating this object as [type].
+ ///
+ /// [typeArguments] are the type arguments used in the instantiation.
DartObjectImpl? typeInstantiate(
TypeSystemImpl typeSystem,
FunctionType type,
- List<DartObjectImpl> typeArguments,
+ List<DartType> typeArguments,
) {
var functionState = _state as FunctionState;
var element = functionState._element;
@@ -1250,11 +1252,11 @@
/// The element representing the function being modeled.
final ExecutableElement? _element;
- final List<DartObjectImpl>? _typeArguments;
+ final List<DartType>? _typeArguments;
/// Initialize a newly created state to represent the function with the given
/// [element].
- FunctionState(this._element, {List<DartObjectImpl>? typeArguments})
+ FunctionState(this._element, {List<DartType>? typeArguments})
: _typeArguments = typeArguments;
@override
diff --git a/pkg/analyzer/lib/src/dart/resolver/invocation_inference_helper.dart b/pkg/analyzer/lib/src/dart/resolver/invocation_inference_helper.dart
index 2fe4604..36357aa 100644
--- a/pkg/analyzer/lib/src/dart/resolver/invocation_inference_helper.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/invocation_inference_helper.dart
@@ -247,7 +247,7 @@
/// generic function type from the surrounding context.
DartType inferTearOff(
Expression expression,
- SimpleIdentifier identifier,
+ SimpleIdentifierImpl identifier,
DartType tearOffType,
) {
var context = InferenceContext.getContext(expression);
@@ -255,12 +255,11 @@
var typeArguments = _typeSystem.inferFunctionTypeInstantiation(
context,
tearOffType,
- errorReporter: _resolver.errorReporter,
+ errorReporter: _errorReporter,
errorNode: expression,
genericMetadataIsEnabled: _genericMetadataIsEnabled,
)!;
- (identifier as SimpleIdentifierImpl).tearOffTypeArgumentTypes =
- typeArguments;
+ identifier.tearOffTypeArgumentTypes = typeArguments;
if (typeArguments.isNotEmpty) {
return tearOffType.instantiate(typeArguments);
}
diff --git a/pkg/analyzer/messages.yaml b/pkg/analyzer/messages.yaml
new file mode 100644
index 0000000..74e44a3
--- /dev/null
+++ b/pkg/analyzer/messages.yaml
@@ -0,0 +1,18738 @@
+AnalysisOptionsErrorCode:
+ INCLUDED_FILE_PARSE_ERROR:
+ template: "{3} in {0}({1}..{2})"
+ comment: |-
+ An error code indicating that there is a syntactic error in the included
+ file.
+
+ Parameters:
+ 0: the path of the file containing the error
+ 1: the starting offset of the text in the file that contains the error
+ 2: the ending offset of the text in the file that contains the error
+ 3: the error message
+ PARSE_ERROR:
+ template: "{0}"
+ comment: |-
+ An error code indicating that there is a syntactic error in the file.
+
+ Parameters:
+ 0: the error message from the parse error
+AnalysisOptionsHintCode:
+ PREVIEW_DART_2_SETTING_DEPRECATED:
+ template: "The 'enablePreviewDart2' setting is deprecated."
+ tip: It is no longer necessary to explicitly enable Dart 2.
+ comment: |-
+ An error code indicating that the enablePreviewDart2 setting is
+ deprecated.
+ STRONG_MODE_SETTING_DEPRECATED:
+ template: "The 'strong-mode: true' setting is deprecated."
+ tip: It is no longer necessary to explicitly enable strong mode.
+ comment: "An error code indicating that strong-mode: true is deprecated."
+ SUPER_MIXINS_SETTING_DEPRECATED:
+ template: "The 'enableSuperMixins' setting is deprecated."
+ tip: "Support has been added to the language for 'mixin' based mixins."
+ comment: |-
+ An error code indicating that the enablePreviewDart2 setting is
+ deprecated.
+AnalysisOptionsWarningCode:
+ ANALYSIS_OPTION_DEPRECATED:
+ template: "The option '{0}' is no longer supported."
+ comment: An error code indicating that the given option is deprecated.
+ INCLUDED_FILE_WARNING:
+ template: "Warning in the included options file {0}({1}..{2}): {3}"
+ comment: |-
+ An error code indicating a specified include file has a warning.
+
+ Parameters:
+ 0: the path of the file containing the warnings
+ 1: the starting offset of the text in the file that contains the warning
+ 2: the ending offset of the text in the file that contains the warning
+ 3: the warning message
+ INCLUDE_FILE_NOT_FOUND:
+ template: "The include file '{0}' in '{1}' can't be found when analyzing '{2}'."
+ comment: |-
+ An error code indicating a specified include file could not be found.
+
+ Parameters:
+ 0: the uri of the file to be included
+ 1: the path of the file containing the include directive
+ 2: the path of the context being analyzed
+ INVALID_OPTION:
+ template: "Invalid option specified for '{0}': {1}"
+ comment: |-
+ An error code indicating that a plugin is being configured with an invalid
+ value for an option and a detail message is provided.
+ INVALID_SECTION_FORMAT:
+ template: "Invalid format for the '{0}' section."
+ comment: |-
+ An error code indicating an invalid format for an options file section.
+
+ Parameters:
+ 0: the section name
+ SPEC_MODE_REMOVED:
+ template: "The option 'strong-mode: false' is no longer supported."
+ tip: "It's recommended to remove the 'strong-mode:' setting (and make your code Dart 2 compliant)."
+ comment: "An error code indicating that strong-mode: false is has been removed."
+ UNRECOGNIZED_ERROR_CODE:
+ template: "'{0}' isn't a recognized error code."
+ comment: |-
+ An error code indicating that an unrecognized error code is being used to
+ specify an error filter.
+
+ Parameters:
+ 0: the unrecognized error code
+ UNSUPPORTED_OPTION_WITHOUT_VALUES:
+ template: "The option '{1}' isn't supported by '{0}'."
+ comment: |-
+ An error code indicating that a plugin is being configured with an
+ unsupported option and legal options are provided.
+
+ Parameters:
+ 0: the plugin name
+ 1: the unsupported option key
+ UNSUPPORTED_OPTION_WITH_LEGAL_VALUE:
+ template: "The option '{1}' isn't supported by '{0}'. Try using the only supported option: '{2}'."
+ comment: |-
+ An error code indicating that a plugin is being configured with an
+ unsupported option where there is just one legal value.
+
+ Parameters:
+ 0: the plugin name
+ 1: the unsupported option key
+ 2: the legal value
+ UNSUPPORTED_OPTION_WITH_LEGAL_VALUES:
+ template: "The option '{1}' isn't supported by '{0}'."
+ tip: "Try using one of the supported options: {2}."
+ comment: |-
+ An error code indicating that a plugin is being configured with an
+ unsupported option and legal options are provided.
+
+ Parameters:
+ 0: the plugin name
+ 1: the unsupported option key
+ 2: legal values
+ UNSUPPORTED_VALUE:
+ template: "The value '{1}' isn't supported by '{0}'."
+ tip: "Try using one of the supported options: {2}."
+ comment: |-
+ An error code indicating that an option entry is being configured with an
+ unsupported value.
+
+ Parameters:
+ 0: the option name
+ 1: the unsupported value
+ 2: legal values
+CompileTimeErrorCode:
+ ABSTRACT_FIELD_CONSTRUCTOR_INITIALIZER:
+ sharedName: ABSTRACT_FIELD_INITIALIZER
+ template: "Abstract fields can't have initializers."
+ tip: "Try removing the field initializer or the 'abstract' keyword from the field declaration."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a field that has the `abstract`
+ modifier also has an initializer.
+
+ #### Example
+
+ The following code produces this diagnostic because `f` is marked as
+ `abstract` and has an initializer:
+
+ ```dart
+ abstract class C {
+ abstract int [!f!] = 0;
+ }
+ ```
+
+ The following code produces this diagnostic because `f` is marked as
+ `abstract` and there's an initializer in the constructor:
+
+ ```dart
+ abstract class C {
+ abstract int f;
+
+ C() : [!f!] = 0;
+ }
+ ```
+
+ #### Common fixes
+
+ If the field must be abstract, then remove the initializer:
+
+ ```dart
+ abstract class C {
+ abstract int f;
+ }
+ ```
+
+ If the field isn't required to be abstract, then remove the keyword:
+
+ ```dart
+ abstract class C {
+ int f = 0;
+ }
+ ```
+ ABSTRACT_FIELD_INITIALIZER:
+ template: "Abstract fields can't have initializers."
+ tip: "Try removing the initializer or the 'abstract' keyword."
+ hasPublishedDocs: true
+ comment: No parameters.
+ ABSTRACT_SUPER_MEMBER_REFERENCE:
+ template: "The {0} '{1}' is always abstract in the supertype."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the display name for the kind of the found abstract member
+ 1: the name of the member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an inherited member is
+ referenced using `super`, but there is no concrete implementation of the
+ member in the superclass chain. Abstract members can't be invoked.
+
+ #### Examples
+
+ The following code produces this diagnostic because `B` doesn't inherit a
+ concrete implementation of `a`:
+
+ ```dart
+ abstract class A {
+ int get a;
+ }
+ class B extends A {
+ int get a => super.[!a!];
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the invocation of the abstract member, possibly replacing it with an
+ invocation of a concrete member.
+ TODO(brianwilkerson) This either needs to be generalized (use 'member'
+ rather than '{0}') or split into multiple codes.
+ AMBIGUOUS_EXPORT:
+ template: "The name '{0}' is defined in the libraries '{1}' and '{2}'."
+ tip: Try removing the export of one of the libraries, or explicitly hiding the name in one of the export directives.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the ambiguous element
+ 1: the name of the first library in which the type is found
+ 2: the name of the second library in which the type is found
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when two or more export directives
+ cause the same name to be exported from multiple libraries.
+
+ #### Example
+
+ Given a file named `a.dart` containing
+
+ ```dart
+ %uri="lib/a.dart"
+ class C {}
+ ```
+
+ And a file named `b.dart` containing
+
+ ```dart
+ %uri="lib/b.dart"
+ class C {}
+ ```
+
+ The following code produces this diagnostic because the name `C` is being
+ exported from both `a.dart` and `b.dart`:
+
+ ```dart
+ export 'a.dart';
+ export [!'b.dart'!];
+ ```
+
+ #### Common fixes
+
+ If none of the names in one of the libraries needs to be exported, then
+ remove the unnecessary export directives:
+
+ ```dart
+ export 'a.dart';
+ ```
+
+ If all of the export directives are needed, then hide the name in all
+ except one of the directives:
+
+ ```dart
+ export 'a.dart';
+ export 'b.dart' hide C;
+ ```
+ AMBIGUOUS_EXTENSION_MEMBER_ACCESS:
+ template: "A member named '{0}' is defined in extensions {1}, and none are more specific."
+ tip: Try using an extension override to specify the extension you want to be chosen.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ 1: the name of the first declaring extension
+ 2: the name of the second declaring extension
+ documentation: |-
+ #### Description
+
+ When code refers to a member of an object (for example, `o.m()` or `o.m` or
+ `o[i]`) where the static type of `o` doesn't declare the member (`m` or
+ `[]`, for example), then the analyzer tries to find the member in an
+ extension. For example, if the member is `m`, then the analyzer looks for
+ extensions that declare a member named `m` and have an extended type that
+ the static type of `o` can be assigned to. When there's more than one such
+ extension in scope, the extension whose extended type is most specific is
+ selected.
+
+ The analyzer produces this diagnostic when none of the extensions has an
+ extended type that's more specific than the extended types of all of the
+ other extensions, making the reference to the member ambiguous.
+
+ #### Examples
+
+ The following code produces this diagnostic because there's no way to
+ choose between the member in `E1` and the member in `E2`:
+
+ ```dart
+ extension E1 on String {
+ int get charCount => 1;
+ }
+
+ extension E2 on String {
+ int get charCount => 2;
+ }
+
+ void f(String s) {
+ print(s.[!charCount!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If you don't need both extensions, then you can delete or hide one of them.
+
+ If you need both, then explicitly select the one you want to use by using
+ an extension override:
+
+ ```dart
+ extension E1 on String {
+ int get charCount => length;
+ }
+
+ extension E2 on String {
+ int get charCount => length;
+ }
+
+ void f(String s) {
+ print(E2(s).charCount);
+ }
+ ```
+ AMBIGUOUS_IMPORT:
+ template: "The name '{0}' is defined in the libraries {1}."
+ tip: "Try using 'as prefix' for one of the import directives, or hiding the name from all but one of the imports."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the ambiguous type
+ 1: the name of the first library that the type is found
+ 2: the name of the second library that the type is found
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name is referenced that is
+ declared in two or more imported libraries.
+
+ #### Examples
+
+ Given a library (`a.dart`) that defines a class (`C` in this example):
+
+ ```dart
+ %uri="lib/a.dart"
+ class A {}
+ class C {}
+ ```
+
+ And a library (`b.dart`) that defines a different class with the same name:
+
+ ```dart
+ %uri="lib/b.dart"
+ class B {}
+ class C {}
+ ```
+
+ The following code produces this diagnostic:
+
+ ```dart
+ import 'a.dart';
+ import 'b.dart';
+
+ void f([!C!] c1, [!C!] c2) {}
+ ```
+
+ #### Common fixes
+
+ If any of the libraries aren't needed, then remove the import directives
+ for them:
+
+ ```dart
+ import 'a.dart';
+
+ void f(C c1, C c2) {}
+ ```
+
+ If the name is still defined by more than one library, then add a `hide`
+ clause to the import directives for all except one library:
+
+ ```dart
+ import 'a.dart' hide C;
+ import 'b.dart';
+
+ void f(C c1, C c2) {}
+ ```
+
+ If you must be able to reference more than one of these types, then add a
+ prefix to each of the import directives, and qualify the references with
+ the appropriate prefix:
+
+ ```dart
+ import 'a.dart' as a;
+ import 'b.dart' as b;
+
+ void f(a.C c1, b.C c2) {}
+ ```
+ AMBIGUOUS_SET_OR_MAP_LITERAL_BOTH:
+ template: "The literal can't be either a map or a set because it contains at least one literal map entry or a spread operator spreading a 'Map', and at least one element which is neither of these."
+ tip: Try removing or changing some of the elements so that all of the elements are consistent.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ Because map and set literals use the same delimiters (`{` and `}`), the
+ analyzer looks at the type arguments and the elements to determine which
+ kind of literal you meant. When there are no type arguments, then the
+ analyzer uses the types of the elements. If all of the elements are literal
+ map entries and all of the spread operators are spreading a `Map` then it's
+ a `Map`. If none of the elements are literal map entries and all of the
+ spread operators are spreading an `Iterable`, then it's a `Set`. If neither
+ of those is true then it's ambiguous.
+
+ The analyzer produces this diagnostic when at least one element is a
+ literal map entry or a spread operator spreading a `Map`, and at least one
+ element is neither of these, making it impossible for the analyzer to
+ determine whether you are writing a map literal or a set literal.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ union(Map<String, String> a, List<String> b, Map<String, String> c) =>
+ [!{...a, ...b, ...c}!];
+ ```
+
+ The list `b` can only be spread into a set, and the maps `a` and `c` can
+ only be spread into a map, and the literal can't be both.
+
+ #### Common fixes
+
+ There are two common ways to fix this problem. The first is to remove all
+ of the spread elements of one kind or another, so that the elements are
+ consistent. In this case, that likely means removing the list and deciding
+ what to do about the now unused parameter:
+
+ ```dart
+ union(Map<String, String> a, List<String> b, Map<String, String> c) =>
+ {...a, ...c};
+ ```
+
+ The second fix is to change the elements of one kind into elements that are
+ consistent with the other elements. For example, you can add the elements
+ of the list as keys that map to themselves:
+
+ ```dart
+ union(Map<String, String> a, List<String> b, Map<String, String> c) =>
+ {...a, for (String s in b) s: s, ...c};
+ ```
+ AMBIGUOUS_SET_OR_MAP_LITERAL_EITHER:
+ template: "This literal must be either a map or a set, but the elements don't have enough information for type inference to work."
+ tip: Try adding type arguments to the literal (one for sets, two for maps).
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ Because map and set literals use the same delimiters (`{` and `}`), the
+ analyzer looks at the type arguments and the elements to determine which
+ kind of literal you meant. When there are no type arguments and all of the
+ elements are spread elements (which are allowed in both kinds of literals)
+ then the analyzer uses the types of the expressions that are being spread.
+ If all of the expressions have the type `Iterable`, then it's a set
+ literal; if they all have the type `Map`, then it's a map literal.
+
+ This diagnostic is produced when none of the expressions being spread have
+ a type that allows the analyzer to decide whether you were writing a map
+ literal or a set literal.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ union(a, b) => [!{...a, ...b}!];
+ ```
+
+ The problem occurs because there are no type arguments, and there is no
+ information about the type of either `a` or `b`.
+
+ #### Common fixes
+
+ There are three common ways to fix this problem. The first is to add type
+ arguments to the literal. For example, if the literal is intended to be a
+ map literal, you might write something like this:
+
+ ```dart
+ union(a, b) => <String, String>{...a, ...b};
+ ```
+
+ The second fix is to add type information so that the expressions have
+ either the type `Iterable` or the type `Map`. You can add an explicit cast
+ or, in this case, add types to the declarations of the two parameters:
+
+ ```dart
+ union(List<int> a, List<int> b) => {...a, ...b};
+ ```
+
+ The third fix is to add context information. In this case, that means
+ adding a return type to the function:
+
+ ```dart
+ Set<String> union(a, b) => {...a, ...b};
+ ```
+
+ In other cases, you might add a type somewhere else. For example, say the
+ original code looks like this:
+
+ ```dart
+ union(a, b) {
+ var x = [!{...a, ...b}!];
+ return x;
+ }
+ ```
+
+ You might add a type annotation on `x`, like this:
+
+ ```dart
+ union(a, b) {
+ Map<String, String> x = {...a, ...b};
+ return x;
+ }
+ ```
+ ARGUMENT_TYPE_NOT_ASSIGNABLE:
+ template: "The argument type '{0}' can't be assigned to the parameter type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the actual argument type
+ 1: the name of the expected type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the static type of an argument
+ can't be assigned to the static type of the corresponding parameter.
+
+ #### Examples
+
+ The following code produces this diagnostic because a `num` can't be
+ assigned to a `String`:
+
+ ```dart
+ %language=2.9
+ String f(String x) => x;
+ String g(num y) => f([!y!]);
+ ```
+
+ #### Common fixes
+
+ If possible, rewrite the code so that the static type is assignable. In the
+ example above you might be able to change the type of the parameter `y`:
+
+ ```dart
+ %language=2.9
+ String f(String x) => x;
+ String g(String y) => f(y);
+ ```
+
+ If that fix isn't possible, then add code to handle the case where the
+ argument value isn't the required type. One approach is to coerce other
+ types to the required type:
+
+ ```dart
+ %language=2.9
+ String f(String x) => x;
+ String g(num y) => f(y.toString());
+ ```
+
+ Another approach is to add explicit type tests and fallback code:
+
+ ```dart
+ %language=2.9
+ String f(String x) => x;
+ String g(num y) => f(y is String ? y : '');
+ ```
+
+ If you believe that the runtime type of the argument will always be the
+ same as the static type of the parameter, and you're willing to risk having
+ an exception thrown at runtime if you're wrong, then add an explicit cast:
+
+ ```dart
+ String f(String x) => x;
+ String g(num y) => f(y as String);
+ ```
+ ASSERT_IN_REDIRECTING_CONSTRUCTOR:
+ template: "A redirecting constructor can't have an 'assert' initializer."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a redirecting constructor (a
+ constructor that redirects to another constructor in the same class) has an
+ assert in the initializer list.
+
+ #### Example
+
+ The following code produces this diagnostic because the unnamed constructor
+ is a redirecting constructor and also has an assert in the initializer
+ list:
+
+ ```dart
+ class C {
+ C(int x) : [!assert(x > 0)!], this.name();
+ C.name() {}
+ }
+ ```
+
+ #### Common fixes
+
+ If the assert isn't needed, then remove it:
+
+ ```dart
+ class C {
+ C(int x) : this.name();
+ C.name() {}
+ }
+ ```
+
+ If the assert is needed, then convert the constructor into a factory
+ constructor:
+
+ ```dart
+ class C {
+ factory C(int x) {
+ assert(x > 0);
+ return C.name();
+ }
+ C.name() {}
+ }
+ ```
+ ASSIGNMENT_TO_CONST:
+ template: "Constant variables can't be assigned a value."
+ tip: "Try removing the assignment, or remove the modifier 'const' from the variable."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds an assignment to a
+ top-level variable, a static field, or a local variable that has the
+ `const` modifier. The value of a compile-time constant can't be changed at
+ runtime.
+
+ #### Example
+
+ The following code produces this diagnostic because `c` is being assigned a
+ value even though it has the `const` modifier:
+
+ ```dart
+ const c = 0;
+
+ void f() {
+ [!c!] = 1;
+ print(c);
+ }
+ ```
+
+ #### Common fixes
+
+ If the variable must be assignable, then remove the `const` modifier:
+
+ ```dart
+ var c = 0;
+
+ void f() {
+ c = 1;
+ print(c);
+ }
+ ```
+
+ If the constant shouldn't be changed, then either remove the assignment or
+ use a local variable in place of references to the constant:
+
+ ```dart
+ const c = 0;
+
+ void f() {
+ var v = 1;
+ print(v);
+ }
+ ```
+ ASSIGNMENT_TO_FINAL:
+ template: "'{0}' can't be used as a setter because it's final."
+ tip: "Try finding a different setter, or making '{0}' non-final."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the final variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds an invocation of a
+ setter, but there's no setter because the field with the same name was
+ declared to be `final` or `const`.
+
+ #### Examples
+
+ The following code produces this diagnostic because `v` is final:
+
+ ```dart
+ class C {
+ final v = 0;
+ }
+
+ f(C c) {
+ c.[!v!] = 1;
+ }
+ ```
+
+ #### Common fixes
+
+ If you need to be able to set the value of the field, then remove the
+ modifier `final` from the field:
+
+ ```dart
+ class C {
+ int v = 0;
+ }
+
+ f(C c) {
+ c.v = 1;
+ }
+ ```
+ ASSIGNMENT_TO_FINAL_LOCAL:
+ template: "The final variable '{0}' can only be set once."
+ tip: "Try making '{0}' non-final."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a local variable that was
+ declared to be final is assigned after it was initialized.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` is final, so it
+ can't have a value assigned to it after it was initialized:
+
+ ```dart
+ void f() {
+ final x = 0;
+ [!x!] = 3;
+ print(x);
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the keyword `final`, and replace it with `var` if there's no type
+ annotation:
+
+ ```dart
+ void f() {
+ var x = 0;
+ x = 3;
+ print(x);
+ }
+ ```
+ ASSIGNMENT_TO_FINAL_NO_SETTER:
+ template: "There isn’t a setter named '{0}' in class '{1}'."
+ tip: Try correcting the name to reference an existing setter, or declare the setter.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a reference to a setter is
+ found; there is no setter defined for the type; but there is a getter
+ defined with the same name.
+
+ #### Examples
+
+ The following code produces this diagnostic because there is no setter
+ named `x` in `C`, but there is a getter named `x`:
+
+ ```dart
+ class C {
+ int get x => 0;
+ set y(int p) {}
+ }
+
+ void f(C c) {
+ c.[!x!] = 1;
+ }
+ ```
+
+ #### Common fixes
+
+ If you want to invoke an existing setter, then correct the name:
+
+ ```dart
+ class C {
+ int get x => 0;
+ set y(int p) {}
+ }
+
+ void f(C c) {
+ c.y = 1;
+ }
+ ```
+
+ If you want to invoke the setter but it just doesn't exist yet, then
+ declare it:
+
+ ```dart
+ class C {
+ int get x => 0;
+ set x(int p) {}
+ set y(int p) {}
+ }
+
+ void f(C c) {
+ c.x = 1;
+ }
+ ```
+ ASSIGNMENT_TO_FUNCTION:
+ template: "Functions can't be assigned a value."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name of a function appears
+ on the left-hand side of an assignment expression.
+
+ #### Example
+
+ The following code produces this diagnostic because the assignment to the
+ function `f` is invalid:
+
+ ```dart
+ void f() {}
+
+ void g() {
+ [!f!] = () {};
+ }
+ ```
+
+ #### Common fixes
+
+ If the right-hand side should be assigned to something else, such as a
+ local variable, then change the left-hand side:
+
+ ```dart
+ void f() {}
+
+ void g() {
+ var x = () {};
+ print(x);
+ }
+ ```
+
+ If the intent is to change the implementation of the function, then define
+ a function-valued variable instead of a function:
+
+ ```dart
+ void Function() f = () {};
+
+ void g() {
+ f = () {};
+ }
+ ```
+ ASSIGNMENT_TO_METHOD:
+ template: "Methods can't be assigned a value."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the target of an assignment is a
+ method.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` can't be assigned a
+ value because it's a method:
+
+ ```dart
+ class C {
+ void f() {}
+
+ void g() {
+ [!f!] = null;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Rewrite the code so that there isn't an assignment to a method.
+ ASSIGNMENT_TO_TYPE:
+ template: "Types can't be assigned a value."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name of a type name appears
+ on the left-hand side of an assignment expression.
+
+ #### Example
+
+ The following code produces this diagnostic because the assignment to the
+ class `C` is invalid:
+
+ ```dart
+ class C {}
+
+ void f() {
+ [!C!] = null;
+ }
+ ```
+
+ #### Common fixes
+
+ If the right-hand side should be assigned to something else, such as a
+ local variable, then change the left-hand side:
+
+ ```dart
+ void f() {}
+
+ void g() {
+ var c = null;
+ print(c);
+ }
+ ```
+ ASYNC_FOR_IN_WRONG_CONTEXT:
+ template: The async for-in loop can only be used in an async function.
+ tip: "Try marking the function body with either 'async' or 'async*', or removing the 'await' before the for-in loop."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an async for-in loop is found in
+ a function or method whose body isn't marked as being either `async` or
+ `async*`.
+
+ #### Example
+
+ The following code produces this diagnostic because the body of `f` isn't
+ marked as being either `async` or `async*`, but `f` contains an async
+ for-in loop:
+
+ ```dart
+ void f(list) {
+ await for (var e [!in!] list) {
+ print(e);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the function should return a `Future`, then mark the body with `async`:
+
+ ```dart
+ Future<void> f(list) async {
+ await for (var e in list) {
+ print(e);
+ }
+ }
+ ```
+
+ If the function should return a `Stream` of values, then mark the body with
+ `async*`:
+
+ ```dart
+ Stream<void> f(list) async* {
+ await for (var e in list) {
+ print(e);
+ }
+ }
+ ```
+
+ If the function should be synchronous, then remove the `await` before the
+ loop:
+
+ ```dart
+ void f(list) {
+ for (var e in list) {
+ print(e);
+ }
+ }
+ ```
+ AWAIT_IN_LATE_LOCAL_VARIABLE_INITIALIZER:
+ template: "The 'await' expression can't be used in a 'late' local variable's initializer."
+ tip: "Try removing the 'late' modifier, or rewriting the initializer without using the 'await' expression."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a local variable that has the
+ `late` modifier uses an `await` expression in the initializer.
+
+ #### Example
+
+ The following code produces this diagnostic because an `await` expression
+ is used in the initializer for `v`, a local variable that is marked `late`:
+
+ ```dart
+ Future<int> f() async {
+ late var v = [!await!] 42;
+ return v;
+ }
+ ```
+
+ #### Common fixes
+
+ If the initializer can be rewritten to not use `await`, then rewrite it:
+
+ ```dart
+ Future<int> f() async {
+ late var v = 42;
+ return v;
+ }
+ ```
+
+ If the initializer can't be rewritten, then remove the `late` modifier:
+
+ ```dart
+ Future<int> f() async {
+ var v = await 42;
+ return v;
+ }
+ ```
+ AWAIT_IN_WRONG_CONTEXT:
+ template: The await expression can only be used in an async function.
+ tip: "Try marking the function body with either 'async' or 'async*'."
+ comment: |-
+ 16.30 Await Expressions: It is a compile-time error if the function
+ immediately enclosing _a_ is not declared asynchronous. (Where _a_ is the
+ await expression.)
+ BODY_MIGHT_COMPLETE_NORMALLY:
+ template: "The body might complete normally, causing 'null' to be returned, but the return type is a potentially non-nullable type."
+ tip: Try adding either a return or a throw statement at the end.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function has a
+ return type that's [potentially non-nullable][] but would implicitly return
+ `null` if control reached the end of the function.
+
+ #### Example
+
+ The following code produces this diagnostic because the method `m` has an
+ implicit return of `null` inserted at the end of the method, but the method
+ is declared to not return `null`:
+
+ ```dart
+ class C {
+ int [!m!](int t) {
+ print(t);
+ }
+ }
+ ```
+
+ The following code produces this diagnostic because the method `m` has an
+ implicit return of `null` inserted at the end of the method, but because
+ the class `C` can be instantiated with a non-nullable type argument, the
+ method is effectively declared to not return `null`:
+
+ ```dart
+ class C<T> {
+ T [!m!](T t) {
+ print(t);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If there's a reasonable value that can be returned, then add a `return`
+ statement at the end of the method:
+
+ ```dart
+ class C<T> {
+ T m(T t) {
+ print(t);
+ return t;
+ }
+ }
+ ```
+
+ If the method won't reach the implicit return, then add a `throw` at the
+ end of the method:
+
+ ```dart
+ class C<T> {
+ T m(T t) {
+ print(t);
+ throw '';
+ }
+ }
+ ```
+
+ If the method intentionally returns `null` at the end, then change the
+ return type so that it's valid to return `null`:
+
+ ```dart
+ class C<T> {
+ T? m(T t) {
+ print(t);
+ }
+ }
+ ```
+ BREAK_LABEL_ON_SWITCH_MEMBER:
+ template: "A break label resolves to the 'case' or 'default' statement."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a break in a case clause inside
+ a switch statement has a label that is associated with another case clause.
+
+ #### Example
+
+ The following code produces this diagnostic because the label `l` is
+ associated with the case clause for `0`:
+
+ ```dart
+ void f(int i) {
+ switch (i) {
+ l: case 0:
+ break;
+ case 1:
+ break [!l!];
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the intent is to transfer control to the statement after the switch,
+ then remove the label from the break statement:
+
+ ```dart
+ void f(int i) {
+ switch (i) {
+ case 0:
+ break;
+ case 1:
+ break;
+ }
+ }
+ ```
+
+ If the intent is to transfer control to a different case block, then use
+ `continue` rather than `break`:
+
+ ```dart
+ void f(int i) {
+ switch (i) {
+ l: case 0:
+ break;
+ case 1:
+ continue l;
+ }
+ }
+ ```
+ BUILT_IN_IDENTIFIER_AS_TYPE:
+ template: "The built-in identifier '{0}' can't be used as a type."
+ tip: Try correcting the name to match an existing type.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the built-in identifier that is being used
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a built-in identifier is used
+ where a type name is expected.
+
+ #### Examples
+
+ The following code produces this diagnostic because `import` can't be used
+ as a type because it's a built-in identifier:
+
+ ```dart
+ [!import!]<int> x;
+ ```
+
+ #### Common fixes
+
+ Replace the built-in identifier with the name of a valid type:
+
+ ```dart
+ List<int> x;
+ ```
+ BUILT_IN_IDENTIFIER_AS_EXTENSION_NAME:
+ sharedName: BUILT_IN_IDENTIFIER_IN_DECLARATION
+ template: "The built-in identifier '{0}' can't be used as an extension name."
+ tip: Try choosing a different name for the extension.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the built-in identifier that is being used
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name used in the declaration
+ of a class, extension, mixin, typedef, type parameter, or import prefix is
+ a built-in identifier. Built-in identifiers can’t be used to name any of
+ these kinds of declarations.
+
+ #### Example
+
+ The following code produces this diagnostic because `mixin` is a built-in
+ identifier:
+
+ ```dart
+ extension [!mixin!] on int {}
+ ```
+
+ #### Common fixes
+
+ Choose a different name for the declaration.
+ BUILT_IN_IDENTIFIER_AS_PREFIX_NAME:
+ sharedName: BUILT_IN_IDENTIFIER_IN_DECLARATION
+ template: "The built-in identifier '{0}' can't be used as a prefix name."
+ tip: Try choosing a different name for the prefix.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the built-in identifier that is being used
+ BUILT_IN_IDENTIFIER_AS_TYPE_NAME:
+ sharedName: BUILT_IN_IDENTIFIER_IN_DECLARATION
+ template: "The built-in identifier '{0}' can't be used as a type name."
+ tip: Try choosing a different name for the type.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the built-in identifier that is being used
+ BUILT_IN_IDENTIFIER_AS_TYPE_PARAMETER_NAME:
+ sharedName: BUILT_IN_IDENTIFIER_IN_DECLARATION
+ template: "The built-in identifier '{0}' can't be used as a type parameter name."
+ tip: Try choosing a different name for the type parameter.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the built-in identifier that is being used
+ BUILT_IN_IDENTIFIER_AS_TYPEDEF_NAME:
+ sharedName: BUILT_IN_IDENTIFIER_IN_DECLARATION
+ template: "The built-in identifier '{0}' can't be used as a typedef name."
+ tip: Try choosing a different name for the typedef.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the built-in identifier that is being used
+ CASE_BLOCK_NOT_TERMINATED:
+ template: "The last statement of the 'case' should be 'break', 'continue', 'rethrow', 'return', or 'throw'."
+ tip: Try adding one of the required statements.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the last statement in a `case`
+ block isn't one of the required terminators: `break`, `continue`,
+ `rethrow`, `return`, or `throw`.
+
+ #### Examples
+
+ The following code produces this diagnostic because the `case` block ends
+ with an assignment:
+
+ ```dart
+ %language=2.9
+ void f(int x) {
+ switch (x) {
+ [!case!] 0:
+ x += 2;
+ default:
+ x += 1;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Add one of the required terminators:
+
+ ```dart
+ %language=2.9
+ void f(int x) {
+ switch (x) {
+ case 0:
+ x += 2;
+ break;
+ default:
+ x += 1;
+ }
+ }
+ ```
+ CASE_EXPRESSION_TYPE_IMPLEMENTS_EQUALS:
+ template: "The switch case expression type '{0}' can't override the '==' operator."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the this of the switch case expression
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type of the expression
+ following the keyword `case` has an implementation of the `==` operator
+ other than the one in `Object`.
+
+ #### Example
+
+ The following code produces this diagnostic because the expression
+ following the keyword `case` (`C(0)`) has the type `C`, and the class `C`
+ overrides the `==` operator:
+
+ ```dart
+ class C {
+ final int value;
+
+ const C(this.value);
+
+ bool operator ==(Object other) {
+ return false;
+ }
+ }
+
+ void f(C c) {
+ switch (c) {
+ case [!C(0)!]:
+ break;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If there isn't a strong reason not to do so, then rewrite the code to use
+ an if-else structure:
+
+ ```dart
+ class C {
+ final int value;
+
+ const C(this.value);
+
+ bool operator ==(Object other) {
+ return false;
+ }
+ }
+
+ void f(C c) {
+ if (c == C(0)) {
+ // ...
+ }
+ }
+ ```
+
+ If you can't rewrite the switch statement and the implementation of `==`
+ isn't necessary, then remove it:
+
+ ```dart
+ class C {
+ final int value;
+
+ const C(this.value);
+ }
+
+ void f(C c) {
+ switch (c) {
+ case C(0):
+ break;
+ }
+ }
+ ```
+
+ If you can't rewrite the switch statement and you can't remove the
+ definition of `==`, then find some other value that can be used to control
+ the switch:
+
+ ```dart
+ class C {
+ final int value;
+
+ const C(this.value);
+
+ bool operator ==(Object other) {
+ return false;
+ }
+ }
+
+ void f(C c) {
+ switch (c.value) {
+ case 0:
+ break;
+ }
+ }
+ ```
+ CASE_EXPRESSION_TYPE_IS_NOT_SWITCH_EXPRESSION_SUBTYPE:
+ template: "The switch case expression type '{0}' must be a subtype of the switch expression type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the case expression
+ 1: the type of the switch expression
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the expression following `case`
+ in a `switch` statement has a static type that isn't a subtype of the
+ static type of the expression following `switch`.
+
+ #### Example
+
+ The following code produces this diagnostic because `1` is an `int`, which
+ isn't a subtype of `String` (the type of `s`):
+
+ ```dart
+ void f(String s) {
+ switch (s) {
+ case [!1!]:
+ break;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the value of the `case` expression is wrong, then change the `case`
+ expression so that it has the required type:
+
+ ```dart
+ void f(String s) {
+ switch (s) {
+ case '1':
+ break;
+ }
+ }
+ ```
+
+ If the value of the `case` expression is correct, then change the `switch`
+ expression to have the required type:
+
+ ```dart
+ void f(int s) {
+ switch (s) {
+ case 1:
+ break;
+ }
+ }
+ ```
+ CAST_TO_NON_TYPE:
+ template: "The name '{0}' isn't a type, so it can't be used in an 'as' expression."
+ tip: "Try changing the name to the name of an existing type, or creating a type with the name '{0}'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name following the `as` in a
+ cast expression is defined to be something other than a type.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` is a variable, not
+ a type:
+
+ ```dart
+ num x = 0;
+ int y = x as [!x!];
+ ```
+
+ #### Common fixes
+
+ Replace the name with the name of a type:
+
+ ```dart
+ num x = 0;
+ int y = x as int;
+ ```
+ CLASS_INSTANTIATION_ACCESS_TO_INSTANCE_MEMBER:
+ sharedName: CLASS_INSTANTIATION_ACCESS_TO_MEMBER
+ template: "The instance member '{0}' can't be accessed on a class instantiation."
+ tip: Try changing the member name to the name of a constructor.
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ CLASS_INSTANTIATION_ACCESS_TO_UNKNOWN_MEMBER:
+ sharedName: CLASS_INSTANTIATION_ACCESS_TO_MEMBER
+ template: "The class '{0} doesn't have a constructor named '{1}."
+ tip: "Try invoking a different constructor, or defining a constructor named '{1}'."
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ CLASS_INSTANTIATION_ACCESS_TO_STATIC_MEMBER:
+ sharedName: CLASS_INSTANTIATION_ACCESS_TO_MEMBER
+ template: "The static member '{0}' can't be accessed on a class instantiation."
+ tip: Try removing the type arguments from the class name, or changing the member name to the name of a constructor.
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ NON_CONSTANT_MAP_KEY_FROM_DEFERRED_LIBRARY:
+ sharedName: COLLECTION_ELEMENT_FROM_DEFERRED_LIBRARY
+ template: "Constant values from a deferred library can't be used as keys in a 'const' map literal."
+ tip: "Try removing the keyword 'const' from the map literal or removing the keyword 'deferred' from the import."
+ hasPublishedDocs: true
+ comment: No parameters.
+ NON_CONSTANT_LIST_ELEMENT_FROM_DEFERRED_LIBRARY:
+ sharedName: COLLECTION_ELEMENT_FROM_DEFERRED_LIBRARY
+ template: "Constant values from a deferred library can't be used as values in a 'const' list literal."
+ tip: "Try removing the keyword 'const' from the list literal or removing the keyword 'deferred' from the import."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a collection literal that is
+ either explicitly (because it's prefixed by the `const` keyword) or
+ implicitly (because it appears in a [constant context][]) a constant
+ contains a value that is declared in a library that is imported using a
+ deferred import. Constants are evaluated at compile time, and values from
+ deferred libraries aren't available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ Given a file (`a.dart`) that defines the constant `zero`:
+
+ ```dart
+ %uri="lib/a.dart"
+ const zero = 0;
+ ```
+
+ The following code produces this diagnostic because the constant list
+ literal contains `a.zero`, which is imported using a `deferred` import:
+
+ ```dart
+ import 'a.dart' deferred as a;
+
+ var l = const [[!a.zero!]];
+ ```
+
+ #### Common fixes
+
+ If the collection literal isn't required to be constant, then remove the
+ `const` keyword:
+
+ ```dart
+ import 'a.dart' deferred as a;
+
+ var l = [a.zero];
+ ```
+
+ If the collection is required to be constant and the imported constant must
+ be referenced, then remove the keyword `deferred` from the import:
+
+ ```dart
+ import 'a.dart' as a;
+
+ var l = const [a.zero];
+ ```
+
+ If you don't need to reference the constant, then replace it with a
+ suitable value:
+
+ ```dart
+ var l = const [0];
+ ```
+ SET_ELEMENT_FROM_DEFERRED_LIBRARY:
+ sharedName: COLLECTION_ELEMENT_FROM_DEFERRED_LIBRARY
+ template: "Constant values from a deferred library can't be used as values in a 'const' set literal."
+ tip: "Try removing the keyword 'const' from the set literal or removing the keyword 'deferred' from the import."
+ hasPublishedDocs: true
+ comment: No parameters.
+ NON_CONSTANT_MAP_VALUE_FROM_DEFERRED_LIBRARY:
+ sharedName: COLLECTION_ELEMENT_FROM_DEFERRED_LIBRARY
+ template: "Constant values from a deferred library can't be used as values in a 'const' map literal."
+ tip: "Try removing the keyword 'const' from the map literal or removing the keyword 'deferred' from the import."
+ hasPublishedDocs: true
+ comment: No parameters.
+ CONCRETE_CLASS_WITH_ABSTRACT_MEMBER:
+ template: "'{0}' must have a method body because '{1}' isn't abstract."
+ tip: "Try making '{1}' abstract, or adding a body to '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the abstract method
+ 1: the name of the enclosing class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a member of a concrete class is
+ found that doesn't have a concrete implementation. Concrete classes aren't
+ allowed to contain abstract members.
+
+ #### Examples
+
+ The following code produces this diagnostic because `m` is an abstract
+ method but `C` isn't an abstract class:
+
+ ```dart
+ class C {
+ [!void m();!]
+ }
+ ```
+
+ #### Common fixes
+
+ If it's valid to create instances of the class, provide an implementation
+ for the member:
+
+ ```dart
+ class C {
+ void m() {}
+ }
+ ```
+
+ If it isn't valid to create instances of the class, mark the class as being
+ abstract:
+
+ ```dart
+ abstract class C {
+ void m();
+ }
+ ```
+ CONFLICTING_CONSTRUCTOR_AND_STATIC_FIELD:
+ sharedName: CONFLICTING_CONSTRUCTOR_AND_STATIC_MEMBER
+ template: "'{0}' can't be used to name both a constructor and a static field in this class."
+ tip: Try renaming either the constructor or the field.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the constructor and field
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a named constructor and either a
+ static method or static field have the same name. Both are accessed using
+ the name of the class, so having the same name makes the reference
+ ambiguous.
+
+ #### Example
+
+ The following code produces this diagnostic because the static field `foo`
+ and the named constructor `foo` have the same name:
+
+ ```dart
+ class C {
+ C.[!foo!]();
+ static int foo = 0;
+ }
+ ```
+
+ The following code produces this diagnostic because the static method `foo`
+ and the named constructor `foo` have the same name:
+
+ ```dart
+ class C {
+ C.[!foo!]();
+ static void foo() {}
+ }
+ ```
+
+ #### Common fixes
+
+ Rename either the member or the constructor.
+ CONFLICTING_CONSTRUCTOR_AND_STATIC_GETTER:
+ sharedName: CONFLICTING_CONSTRUCTOR_AND_STATIC_MEMBER
+ template: "'{0}' can't be used to name both a constructor and a static getter in this class."
+ tip: Try renaming either the constructor or the getter.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the constructor and getter
+ CONFLICTING_CONSTRUCTOR_AND_STATIC_METHOD:
+ sharedName: CONFLICTING_CONSTRUCTOR_AND_STATIC_MEMBER
+ template: "'{0}' can't be used to name both a constructor and a static method in this class."
+ tip: Try renaming either the constructor or the method.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the constructor
+ CONFLICTING_CONSTRUCTOR_AND_STATIC_SETTER:
+ sharedName: CONFLICTING_CONSTRUCTOR_AND_STATIC_MEMBER
+ template: "'{0}' can't be used to name both a constructor and a static setter in this class."
+ tip: Try renaming either the constructor or the setter.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the constructor and setter
+ CONFLICTING_FIELD_AND_METHOD:
+ template: "Class '{0}' can't define field '{1}' and have method '{2}.{1}' with the same name."
+ tip: "Try converting the getter to a method, or renaming the field to a name that doesn't conflict."
+ comment: |-
+ 10.11 Class Member Conflicts: Let `C` be a class. It is a compile-time
+ error if `C` declares a getter or a setter with basename `n`, and has a
+ method named `n`.
+
+ Parameters:
+ 0: the name of the class defining the conflicting field
+ 1: the name of the conflicting field
+ 2: the name of the class defining the method with which the field conflicts
+ CONFLICTING_GENERIC_INTERFACES:
+ template: "The class '{0}' can't implement both '{1}' and '{2}' because the type arguments are different."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the class implementing the conflicting interface
+ 1: the first conflicting type
+ 2: the second conflicting type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class attempts to implement a
+ generic interface multiple times, and the values of the type arguments
+ aren't the same.
+
+ #### Example
+
+ The following code produces this diagnostic because `C` is defined to
+ implement both `I<int>` (because it extends `A`) and `I<String>` (because
+ it implements`B`), but `int` and `String` aren't the same type:
+
+ ```dart
+ class I<T> {}
+ class A implements I<int> {}
+ class B implements I<String> {}
+ class [!C!] extends A implements B {}
+ ```
+
+ #### Common fixes
+
+ Rework the type hierarchy to avoid this situation. For example, you might
+ make one or both of the inherited types generic so that `C` can specify the
+ same type for both type arguments:
+
+ ```dart
+ class I<T> {}
+ class A<S> implements I<S> {}
+ class B implements I<String> {}
+ class C extends A<String> implements B {}
+ ```
+ CONFLICTING_METHOD_AND_FIELD:
+ template: "Class '{0}' can't define method '{1}' and have field '{2}.{1}' with the same name."
+ tip: "Try converting the method to a getter, or renaming the method to a name that doesn't conflict."
+ comment: |-
+ 10.11 Class Member Conflicts: Let `C` be a class. It is a compile-time
+ error if `C` declares a method named `n`, and has a getter or a setter
+ with basename `n`.
+
+ Parameters:
+ 0: the name of the class defining the conflicting method
+ 1: the name of the conflicting method
+ 2: the name of the class defining the field with which the method conflicts
+ CONFLICTING_STATIC_AND_INSTANCE:
+ template: "Class '{0}' can't define static member '{1}' and have instance member '{2}.{1}' with the same name."
+ tip: "Try renaming the member to a name that doesn't conflict."
+ comment: |-
+ 10.11 Class Member Conflicts: Let `C` be a class. It is a compile-time
+ error if `C` declares a static member with basename `n`, and has an
+ instance member with basename `n`.
+
+ Parameters:
+ 0: the name of the class defining the conflicting member
+ 1: the name of the conflicting static member
+ 2: the name of the class defining the field with which the method conflicts
+ CONFLICTING_TYPE_VARIABLE_AND_CLASS:
+ sharedName: CONFLICTING_TYPE_VARIABLE_AND_CONTAINER
+ template: "'{0}' can't be used to name both a type variable and the class in which the type variable is defined."
+ tip: Try renaming either the type variable or the class.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class, mixin, or extension
+ declaration declares a type parameter with the same name as the class,
+ mixin, or extension that declares it.
+
+ #### Example
+
+ The following code produces this diagnostic because the type parameter `C`
+ has the same name as the class `C` of which it's a part:
+
+ ```dart
+ class C<[!C!]> {}
+ ```
+
+ #### Common fixes
+
+ Rename either the type parameter, or the class, mixin, or extension:
+
+ ```dart
+ class C<T> {}
+ ```
+ CONFLICTING_TYPE_VARIABLE_AND_EXTENSION:
+ sharedName: CONFLICTING_TYPE_VARIABLE_AND_CONTAINER
+ template: "'{0}' can't be used to name both a type variable and the extension in which the type variable is defined."
+ tip: Try renaming either the type variable or the extension.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type variable
+ CONFLICTING_TYPE_VARIABLE_AND_MIXIN:
+ sharedName: CONFLICTING_TYPE_VARIABLE_AND_CONTAINER
+ template: "'{0}' can't be used to name both a type variable and the mixin in which the type variable is defined."
+ tip: Try renaming either the type variable or the mixin.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type variable
+ CONFLICTING_TYPE_VARIABLE_AND_MEMBER_CLASS:
+ sharedName: CONFLICTING_TYPE_VARIABLE_AND_MEMBER
+ template: "'{0}' can't be used to name both a type variable and a member in this class."
+ tip: Try renaming either the type variable or the member.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class, mixin, or extension
+ declaration declares a type parameter with the same name as one of the
+ members of the class, mixin, or extension that declares it.
+
+ #### Example
+
+ The following code produces this diagnostic because the type parameter `T`
+ has the same name as the field `T`:
+
+ ```dart
+ class C<[!T!]> {
+ int T = 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Rename either the type parameter or the member with which it conflicts:
+
+ ```dart
+ class C<T> {
+ int total = 0;
+ }
+ ```
+ CONFLICTING_TYPE_VARIABLE_AND_MEMBER_MIXIN:
+ sharedName: CONFLICTING_TYPE_VARIABLE_AND_MEMBER
+ template: "'{0}' can't be used to name both a type variable and a member in this mixin."
+ tip: Try renaming either the type variable or the member.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type variable
+ CONFLICTING_TYPE_VARIABLE_AND_MEMBER_EXTENSION:
+ sharedName: CONFLICTING_TYPE_VARIABLE_AND_MEMBER
+ template: "'{0}' can't be used to name both a type variable and a member in this extension."
+ tip: Try renaming either the type variable or the member.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type variable
+ CONST_CONSTRUCTOR_FIELD_TYPE_MISMATCH:
+ template: "In a const constructor, a value of type '{0}' can't be assigned to the field '{1}', which has type '{2}'."
+ tip: "Try using a subtype, or removing the keyword 'const'."
+ comment: |-
+ 16.12.2 Const: It is a compile-time error if evaluation of a constant
+ object results in an uncaught exception being thrown.
+ CONST_CONSTRUCTOR_PARAM_TYPE_MISMATCH:
+ template: "A value of type '{0}' can't be assigned to a parameter of type '{1}' in a const constructor."
+ tip: "Try using a subtype, or removing the keyword 'const'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the runtime value of the argument
+ 1: the static type of the parameter
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the runtime type of a constant
+ value can't be assigned to the static type of a constant constructor's
+ parameter.
+
+ #### Example
+
+ The following code produces this diagnostic because the runtime type of `i`
+ is `int`, which can't be assigned to the static type of `s`:
+
+ ```dart
+ class C {
+ final String s;
+
+ const C(this.s);
+ }
+
+ const dynamic i = 0;
+
+ void f() {
+ const C([!i!]);
+ }
+ ```
+
+ #### Common fixes
+
+ Pass a value of the correct type to the constructor:
+
+ ```dart
+ class C {
+ final String s;
+
+ const C(this.s);
+ }
+
+ const dynamic i = 0;
+
+ void f() {
+ const C('$i');
+ }
+ ```
+ CONST_CONSTRUCTOR_THROWS_EXCEPTION:
+ template: "Const constructors can't throw exceptions."
+ tip: "Try removing the throw statement, or removing the keyword 'const'."
+ comment: |-
+ 16.12.2 Const: It is a compile-time error if evaluation of a constant
+ object results in an uncaught exception being thrown.
+ CONST_CONSTRUCTOR_WITH_FIELD_INITIALIZED_BY_NON_CONST:
+ template: "Can't define the 'const' constructor because the field '{0}' is initialized with a non-constant value."
+ tip: "Try initializing the field to a constant value, or removing the keyword 'const' from the constructor."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the field
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor has the keyword
+ `const`, but a field in the class is initialized to a non-constant value.
+
+ #### Example
+
+ The following code produces this diagnostic because the field `s` is
+ initialized to a non-constant value:
+
+ ```dart
+ class C {
+ final String s = 3.toString();
+ [!const!] C();
+ }
+ ```
+
+ #### Common fixes
+
+ If the field can be initialized to a constant value, then change the
+ initializer to a constant expression:
+
+ ```dart
+ class C {
+ final String s = '3';
+ const C();
+ }
+ ```
+
+ If the field can't be initialized to a constant value, then remove the
+ keyword `const` from the constructor:
+
+ ```dart
+ class C {
+ final String s = 3.toString();
+ C();
+ }
+ ```
+ CONST_CONSTRUCTOR_WITH_MIXIN_WITH_FIELD:
+ template: "This constructor can't be declared 'const' because a mixin adds the instance field: {0}."
+ tip: "Try removing the 'const' keyword or removing the 'with' clause from the class declaration, or removing the field from the mixin class."
+ comment: |-
+ 7.6.3 Constant Constructors: The superinitializer that appears, explicitly
+ or implicitly, in the initializer list of a constant constructor must
+ specify a constant constructor of the superclass of the immediately
+ enclosing class or a compile-time error occurs.
+
+ 12.1 Mixin Application: For each generative constructor named ... an
+ implicitly declared constructor named ... is declared. If Sq is a
+ generative const constructor, and M does not declare any fields, Cq is
+ also a const constructor.
+
+ Parameters:
+ 0: the name of the instance field.
+ CONST_CONSTRUCTOR_WITH_MIXIN_WITH_FIELDS:
+ sharedName: CONST_CONSTRUCTOR_WITH_MIXIN_WITH_FIELD
+ template: "This constructor can't be declared 'const' because the mixins add the instance fields: {0}."
+ tip: "Try removing the 'const' keyword or removing the 'with' clause from the class declaration, or removing the fields from the mixin classes."
+ comment: |-
+ 7.6.3 Constant Constructors: The superinitializer that appears, explicitly
+ or implicitly, in the initializer list of a constant constructor must
+ specify a constant constructor of the superclass of the immediately
+ enclosing class or a compile-time error occurs.
+
+ 12.1 Mixin Application: For each generative constructor named ... an
+ implicitly declared constructor named ... is declared. If Sq is a
+ generative const constructor, and M does not declare any fields, Cq is
+ also a const constructor.
+
+ Parameters:
+ 0: the names of the instance fields.
+ CONST_CONSTRUCTOR_WITH_NON_CONST_SUPER:
+ template: "A constant constructor can't call a non-constant super constructor of '{0}'."
+ tip: "Try calling a constant constructor in the superclass, or removing the keyword 'const' from the constructor."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the superclass
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor that is marked as
+ `const` invokes a constructor from its superclass that isn't marked as
+ `const`.
+
+ #### Example
+
+ The following code produces this diagnostic because the `const` constructor
+ in `B` invokes the constructor `nonConst` from the class `A`, and the
+ superclass constructor isn't a `const` constructor:
+
+ ```dart
+ class A {
+ const A();
+ A.nonConst();
+ }
+
+ class B extends A {
+ const B() : [!super.nonConst()!];
+ }
+ ```
+
+ #### Common fixes
+
+ If it isn't essential to invoke the superclass constructor that is
+ currently being invoked, then invoke a constant constructor from the
+ superclass:
+
+ ```dart
+ class A {
+ const A();
+ A.nonConst();
+ }
+
+ class B extends A {
+ const B() : super();
+ }
+ ```
+
+ If it's essential that the current constructor be invoked and if you can
+ modify it, then add `const` to the constructor in the superclass:
+
+ ```dart
+ class A {
+ const A();
+ const A.nonConst();
+ }
+
+ class B extends A {
+ const B() : super.nonConst();
+ }
+ ```
+
+ If it's essential that the current constructor be invoked and you can't
+ modify it, then remove `const` from the constructor in the subclass:
+
+ ```dart
+ class A {
+ const A();
+ A.nonConst();
+ }
+
+ class B extends A {
+ B() : super.nonConst();
+ }
+ ```
+ CONST_CONSTRUCTOR_WITH_NON_FINAL_FIELD:
+ template: "Can't define a const constructor for a class with non-final fields."
+ tip: "Try making all of the fields final, or removing the keyword 'const' from the constructor."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor is marked as a
+ const constructor, but the constructor is defined in a class that has at
+ least one non-final instance field (either directly or by inheritance).
+
+ #### Examples
+
+ The following code produces this diagnostic because the field `x` isn't
+ final:
+
+ ```dart
+ class C {
+ int x;
+
+ const [!C!](this.x);
+ }
+ ```
+
+ #### Common fixes
+
+ If it's possible to mark all of the fields as final, then do so:
+
+ ```dart
+ class C {
+ final int x;
+
+ const C(this.x);
+ }
+ ```
+
+ If it isn't possible to mark all of the fields as final, then remove the
+ keyword `const` from the constructor:
+
+ ```dart
+ class C {
+ int x;
+
+ C(this.x);
+ }
+ ```
+ CONST_DEFERRED_CLASS:
+ template: "Deferred classes can't be created with 'const'."
+ tip: "Try using 'new' to create the instance, or changing the import to not be deferred."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class from a library that is
+ imported using a deferred import is used to create a `const` object.
+ Constants are evaluated at compile time, and classes from deferred
+ libraries aren't available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ The following code produces this diagnostic because it attempts to create a
+ `const` instance of a class from a deferred library:
+
+ ```dart
+ import 'dart:convert' deferred as convert;
+
+ const json2 = [!convert.JsonCodec()!];
+ ```
+
+ #### Common fixes
+
+ If the object isn't required to be a constant, then change the code so that
+ a non-constant instance is created:
+
+ ```dart
+ import 'dart:convert' deferred as convert;
+
+ final json2 = convert.JsonCodec();
+ ```
+
+ If the object must be a constant, then remove `deferred` from the import
+ directive:
+
+ ```dart
+ import 'dart:convert' as convert;
+
+ const json2 = convert.JsonCodec();
+ ```
+ CONST_EVAL_THROWS_EXCEPTION:
+ template: Evaluation of this constant expression throws an exception.
+ comment: |-
+ 16.12.2 Const: It is a compile-time error if evaluation of a constant
+ object results in an uncaught exception being thrown.
+ CONST_EVAL_THROWS_IDBZE:
+ template: Evaluation of this constant expression throws an IntegerDivisionByZeroException.
+ comment: |-
+ 16.12.2 Const: It is a compile-time error if evaluation of a constant
+ object results in an uncaught exception being thrown.
+ CONST_EVAL_TYPE_BOOL:
+ template: "In constant expressions, operands of this operator must be of type 'bool'."
+ comment: |-
+ 16.12.2 Const: An expression of one of the forms !e, e1 && e2 or e1 || e2,
+ where e, e1 and e2 are constant expressions that evaluate to a boolean
+ value.
+ CONST_EVAL_TYPE_BOOL_INT:
+ template: "In constant expressions, operands of this operator must be of type 'bool' or 'int'."
+ comment: |-
+ 16.12.2 Const: An expression of one of the forms !e, e1 && e2 or e1 || e2,
+ where e, e1 and e2 are constant expressions that evaluate to a boolean
+ value.
+ CONST_EVAL_TYPE_BOOL_NUM_STRING:
+ template: "In constant expressions, operands of this operator must be of type 'bool', 'num', 'String' or 'null'."
+ comment: |-
+ 16.12.2 Const: An expression of one of the forms e1 == e2 or e1 != e2 where
+ e1 and e2 are constant expressions that evaluate to a numeric, string or
+ boolean value or to null.
+ CONST_EVAL_TYPE_INT:
+ template: "In constant expressions, operands of this operator must be of type 'int'."
+ comment: |-
+ 16.12.2 Const: An expression of one of the forms ~e, e1 ^ e2, e1 & e2,
+ e1 | e2, e1 >> e2 or e1 << e2, where e, e1 and e2 are constant expressions
+ that evaluate to an integer value or to null.
+ CONST_EVAL_TYPE_NUM:
+ template: "In constant expressions, operands of this operator must be of type 'num'."
+ comment: |-
+ 16.12.2 Const: An expression of one of the forms e, e1 + e2, e1 - e2, e1
+ e2, e1 / e2, e1 ~/ e2, e1 > e2, e1 < e2, e1 >= e2, e1 <= e2 or e1 % e2,
+ where e, e1 and e2 are constant expressions that evaluate to a numeric
+ value or to null.
+ CONST_EVAL_TYPE_TYPE:
+ template: "In constant expressions, operands of this operator must be of type 'Type'."
+ CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE:
+ template: Const variables must be initialized with a constant value.
+ tip: Try changing the initializer to be a constant expression.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a value that isn't statically
+ known to be a constant is assigned to a variable that's declared to be a
+ `const` variable.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` isn't declared to
+ be `const`:
+
+ ```dart
+ var x = 0;
+ const y = [!x!];
+ ```
+
+ #### Common fixes
+
+ If the value being assigned can be declared to be `const`, then change the
+ declaration:
+
+ ```dart
+ const x = 0;
+ const y = x;
+ ```
+
+ If the value can't be declared to be `const`, then remove the `const`
+ modifier from the variable, possibly using `final` in its place:
+
+ ```dart
+ var x = 0;
+ final y = x;
+ ```
+ CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE_FROM_DEFERRED_LIBRARY:
+ template: "Constant values from a deferred library can't be used to initialize a 'const' variable."
+ tip: Try initializing the variable without referencing members of the deferred library, or changing the import to not be deferred.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `const` variable is
+ initialized using a `const` variable from a library that is imported using
+ a deferred import. Constants are evaluated at compile time, and values from
+ deferred libraries aren't available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ The following code produces this diagnostic because the variable `pi` is
+ being initialized using the constant `math.pi` from the library
+ `dart:math`, and `dart:math` is imported as a deferred library:
+
+ ```dart
+ import 'dart:math' deferred as math;
+
+ const pi = [!math.pi!];
+ ```
+
+ #### Common fixes
+
+ If you need to reference the value of the constant from the imported
+ library, then remove the keyword `deferred`:
+
+ ```dart
+ import 'dart:math' as math;
+
+ const pi = math.pi;
+ ```
+
+ If you don't need to reference the imported constant, then remove the
+ reference:
+
+ ```dart
+ const pi = 3.14;
+ ```
+ CONST_INSTANCE_FIELD:
+ template: Only static fields can be declared as const.
+ tip: "Try declaring the field as final, or adding the keyword 'static'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an instance field is marked as
+ being const.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` is an instance
+ field:
+
+ ```dart
+ class C {
+ [!const!] int f = 3;
+ }
+ ```
+
+ #### Common fixes
+
+ If the field needs to be an instance field, then remove the keyword
+ `const`, or replace it with `final`:
+
+ ```dart
+ class C {
+ final int f = 3;
+ }
+ ```
+
+ If the field really should be a const field, then make it a static field:
+
+ ```dart
+ class C {
+ static const int f = 3;
+ }
+ ```
+ CONST_MAP_KEY_EXPRESSION_TYPE_IMPLEMENTS_EQUALS:
+ template: "The type of a key in a constant map can't override the '==' operator, but the class '{0}' does."
+ tip: "Try using a different value for the key, or removing the keyword 'const' from the map."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the entry's key
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the class of object used as a
+ key in a constant map literal implements the `==` operator. The
+ implementation of constant maps uses the `==` operator, so any
+ implementation other than the one inherited from `Object` requires
+ executing arbitrary code at compile time, which isn't supported.
+
+ #### Example
+
+ The following code produces this diagnostic because the constant map
+ contains a key whose type is `C`, and the class `C` overrides the
+ implementation of `==`:
+
+ ```dart
+ class C {
+ const C();
+
+ bool operator ==(Object other) => true;
+ }
+
+ const map = {[!C()!] : 0};
+ ```
+
+ #### Common fixes
+
+ If you can remove the implementation of `==` from the class, then do so:
+
+ ```dart
+ class C {
+ const C();
+ }
+
+ const map = {C() : 0};
+ ```
+
+ If you can't remove the implementation of `==` from the class, then make
+ the map be non-constant:
+
+ ```dart
+ class C {
+ const C();
+
+ bool operator ==(Object other) => true;
+ }
+
+ final map = {C() : 0};
+ ```
+ CONST_NOT_INITIALIZED:
+ template: "The constant '{0}' must be initialized."
+ tip: Try adding an initialization to the declaration.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the uninitialized final variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a variable that is declared to
+ be a constant doesn't have an initializer.
+
+ #### Examples
+
+ The following code produces this diagnostic because `c` isn't initialized:
+
+ ```dart
+ const [!c!];
+ ```
+
+ #### Common fixes
+
+ Add an initializer:
+
+ ```dart
+ const c = 'c';
+ ```
+ CONST_SET_ELEMENT_TYPE_IMPLEMENTS_EQUALS:
+ template: "The type of an element in a constant set can't override the '==' operator, but the type '{0}' does."
+ tip: "Try using a different value for the element, or removing the keyword 'const' from the set."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the element
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the class of object used as an
+ element in a constant set literal implements the `==` operator. The
+ implementation of constant sets uses the `==` operator, so any
+ implementation other than the one inherited from `Object` requires
+ executing arbitrary code at compile time, which isn't supported.
+
+ #### Example
+
+ The following code produces this diagnostic because the constant set
+ contains an element whose type is `C`, and the class `C` overrides the
+ implementation of `==`:
+
+ ```dart
+ class C {
+ const C();
+
+ bool operator ==(Object other) => true;
+ }
+
+ const set = {[!C()!]};
+ ```
+
+ #### Common fixes
+
+ If you can remove the implementation of `==` from the class, then do so:
+
+ ```dart
+ class C {
+ const C();
+ }
+
+ const set = {C()};
+ ```
+
+ If you can't remove the implementation of `==` from the class, then make
+ the set be non-constant:
+
+ ```dart
+ class C {
+ const C();
+
+ bool operator ==(Object other) => true;
+ }
+
+ final set = {C()};
+ ```
+ CONST_SPREAD_EXPECTED_LIST_OR_SET:
+ template: A list or a set is expected in this spread.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the expression of a spread
+ operator in a constant list or set evaluates to something other than a list
+ or a set.
+
+ #### Examples
+
+ The following code produces this diagnostic because the value of `list1` is
+ `null`, which is neither a list nor a set:
+
+ ```dart
+ %language=2.9
+ const List<int> list1 = null;
+ const List<int> list2 = [...[!list1!]];
+ ```
+
+ #### Common fixes
+
+ Change the expression to something that evaluates to either a constant list
+ or a constant set:
+
+ ```dart
+ %language=2.9
+ const List<int> list1 = [];
+ const List<int> list2 = [...list1];
+ ```
+ CONST_SPREAD_EXPECTED_MAP:
+ template: A map is expected in this spread.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the expression of a spread
+ operator in a constant map evaluates to something other than a map.
+
+ #### Examples
+
+ The following code produces this diagnostic because the value of `map1` is
+ `null`, which isn't a map:
+
+ ```dart
+ %language=2.9
+ const Map<String, int> map1 = null;
+ const Map<String, int> map2 = {...[!map1!]};
+ ```
+
+ #### Common fixes
+
+ Change the expression to something that evaluates to a constant map:
+
+ ```dart
+ %language=2.9
+ const Map<String, int> map1 = {};
+ const Map<String, int> map2 = {...map1};
+ ```
+ CONST_WITH_NON_CONST:
+ template: "The constructor being called isn't a const constructor."
+ tip: "Try removing 'const' from the constructor invocation."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the keyword `const` is used to
+ invoke a constructor that isn't marked with `const`.
+
+ #### Examples
+
+ The following code produces this diagnostic because the constructor in `A`
+ isn't a const constructor:
+
+ ```dart
+ class A {
+ A();
+ }
+
+ A f() => [!const!] A();
+ ```
+
+ #### Common fixes
+
+ If it's desirable and possible to make the class a constant class (by
+ making all of the fields of the class, including inherited fields, final),
+ then add the keyword `const` to the constructor:
+
+ ```dart
+ class A {
+ const A();
+ }
+
+ A f() => const A();
+ ```
+
+ Otherwise, remove the keyword `const`:
+
+ ```dart
+ class A {
+ A();
+ }
+
+ A f() => A();
+ ```
+ CONST_WITH_NON_CONSTANT_ARGUMENT:
+ template: Arguments of a constant creation must be constant expressions.
+ tip: "Try making the argument a valid constant, or use 'new' to call the constructor."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a const constructor is invoked
+ with an argument that isn't a constant expression.
+
+ #### Examples
+
+ The following code produces this diagnostic because `i` isn't a constant:
+
+ ```dart
+ class C {
+ final int i;
+ const C(this.i);
+ }
+ C f(int i) => const C([!i!]);
+ ```
+
+ #### Common fixes
+
+ Either make all of the arguments constant expressions, or remove the
+ `const` keyword to use the non-constant form of the constructor:
+
+ ```dart
+ class C {
+ final int i;
+ const C(this.i);
+ }
+ C f(int i) => C(i);
+ ```
+ CONST_WITH_TYPE_PARAMETERS:
+ template: "A constant creation can't use a type parameter as a type argument."
+ tip: Try replacing the type parameter with a different type.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a type parameter is used as a
+ type argument in a `const` invocation of a constructor. This isn't allowed
+ because the value of the type parameter (the actual type that will be used
+ at runtime) can't be known at compile time.
+
+ #### Example
+
+ The following code produces this diagnostic because the type parameter `T`
+ is being used as a type argument when creating a constant:
+
+ ```dart
+ class C<T> {
+ const C();
+ }
+
+ C<T> newC<T>() => const C<[!T!]>();
+ ```
+
+ #### Common fixes
+
+ If the type that will be used for the type parameter can be known at
+ compile time, then remove the use of the type parameter:
+
+ ```dart
+ class C<T> {
+ const C();
+ }
+
+ C<int> newC() => const C<int>();
+ ```
+
+ If the type that will be used for the type parameter can't be known until
+ runtime, then remove the keyword `const`:
+
+ ```dart
+ class C<T> {
+ const C();
+ }
+
+ C<T> newC<T>() => C<T>();
+ ```
+ CONST_WITH_TYPE_PARAMETERS_CONSTRUCTOR_TEAROFF:
+ sharedName: CONST_WITH_TYPE_PARAMETERS
+ template: "A constant constructor tearoff can't use a type parameter as a type argument."
+ tip: Try replacing the type parameter with a different type.
+ hasPublishedDocs: true
+ comment: No parameters.
+ CONST_WITH_TYPE_PARAMETERS_FUNCTION_TEAROFF:
+ sharedName: CONST_WITH_TYPE_PARAMETERS
+ template: "A constant function tearoff can't use a type parameter as a type argument."
+ tip: Try replacing the type parameter with a different type.
+ hasPublishedDocs: true
+ comment: No parameters.
+ CONST_WITH_UNDEFINED_CONSTRUCTOR:
+ template: "The class '{0}' doesn't have a constant constructor '{1}'."
+ tip: Try calling a different constructor.
+ comment: |-
+ 16.12.2 Const: It is a compile-time error if <i>T.id</i> is not the name of
+ a constant constructor declared by the type <i>T</i>.
+
+ Parameters:
+ 0: the name of the type
+ 1: the name of the requested constant constructor
+ CONST_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT:
+ template: "The class '{0}' doesn't have an unnamed constant constructor."
+ tip: Try calling a different constructor.
+ comment: |-
+ 16.12.2 Const: It is a compile-time error if <i>T.id</i> is not the name of
+ a constant constructor declared by the type <i>T</i>.
+
+ Parameters:
+ 0: the name of the type
+ CONTINUE_LABEL_ON_SWITCH:
+ template: A continue label resolves to switch, must be loop or switch member
+ COULD_NOT_INFER:
+ template: "Couldn't infer type parameter '{0}'.{1}"
+ comment: |-
+ Parameters:
+ 0: the name of the type parameter
+ 1: detail text explaining why the type could not be inferred
+ NEW_WITH_NON_TYPE:
+ sharedName: CREATION_WITH_NON_TYPE
+ template: "The name '{0}' isn't a class."
+ tip: Try correcting the name to match an existing class.
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the non-type element
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an instance creation using
+ either `new` or `const` specifies a name that isn't defined as a class.
+
+ #### Example
+
+ The following code produces this diagnostic because `f` is a function
+ rather than a class:
+
+ ```dart
+ int f() => 0;
+
+ void g() {
+ new [!f!]();
+ }
+ ```
+
+ #### Common fixes
+
+ If a class should be created, then replace the invalid name with the name
+ of a valid class:
+
+ ```dart
+ int f() => 0;
+
+ void g() {
+ new Object();
+ }
+ ```
+
+ If the name is the name of a function and you want that function to be
+ invoked, then remove the `new` or `const` keyword:
+
+ ```dart
+ int f() => 0;
+
+ void g() {
+ f();
+ }
+ ```
+ CONST_WITH_NON_TYPE:
+ sharedName: CREATION_WITH_NON_TYPE
+ template: "The name '{0}' isn't a class."
+ tip: Try correcting the name to match an existing class.
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the non-type element
+ DEFAULT_LIST_CONSTRUCTOR:
+ template: "The default 'List' constructor isn't available when null safety is enabled."
+ tip: "Try using a list literal, 'List.filled' or 'List.generate'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds a use of the default
+ constructor for the class `List` in code that has opted in to null safety.
+
+ #### Example
+
+ Assuming the following code is opted in to null safety, it produces this
+ diagnostic because it uses the default `List` constructor:
+
+ ```dart
+ var l = [!List<int>!]();
+ ```
+
+ #### Common fixes
+
+ If no initial size is provided, then convert the code to use a list
+ literal:
+
+ ```dart
+ var l = <int>[];
+ ```
+
+ If an initial size needs to be provided and there is a single reasonable
+ initial value for the elements, then use `List.filled`:
+
+ ```dart
+ var l = List.filled(3, 0);
+ ```
+
+ If an initial size needs to be provided but each element needs to be
+ computed, then use `List.generate`:
+
+ ```dart
+ var l = List.generate(3, (i) => i);
+ ```
+ DEFAULT_VALUE_IN_REDIRECTING_FACTORY_CONSTRUCTOR:
+ template: "Default values aren't allowed in factory constructors that redirect to another constructor."
+ tip: Try removing the default value.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a factory constructor that
+ redirects to another constructor specifies a default value for an optional
+ parameter.
+
+ #### Example
+
+ The following code produces this diagnostic because the factory constructor
+ in `A` has a default value for the optional parameter `x`:
+
+ ```dart
+ class A {
+ factory A([int [!x!] = 0]) = B;
+ }
+
+ class B implements A {
+ B([int x = 1]) {}
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the default value from the factory constructor:
+
+ ```dart
+ class A {
+ factory A([int x]) = B;
+ }
+
+ class B implements A {
+ B([int x = 1]) {}
+ }
+ ```
+
+ Note that this fix might change the value used when the optional parameter
+ is omitted. If that happens, and if that change is a problem, then consider
+ making the optional parameter a required parameter in the factory method:
+
+ ```dart
+ class A {
+ factory A(int x) = B;
+ }
+
+ class B implements A {
+ B([int x = 1]) {}
+ }
+ ```
+ DEFAULT_VALUE_ON_REQUIRED_PARAMETER:
+ template: "Required named parameters can't have a default value."
+ tip: "Try removing either the default value or the 'required' modifier."
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a named parameter has both the
+ `required` modifier and a default value. If the parameter is required, then
+ a value for the parameter is always provided at the call sites, so the
+ default value can never be used.
+
+ #### Examples
+
+ The following code generates this diagnostic:
+
+ ```dart
+ void log({required String [!message!] = 'no message'}) {}
+ ```
+
+ #### Common fixes
+
+ If the parameter is really required, then remove the default value:
+
+ ```dart
+ void log({required String message}) {}
+ ```
+
+ If the parameter isn't always required, then remove the `required`
+ modifier:
+
+ ```dart
+ void log({String message = 'no message'}) {}
+ ```
+ DEFERRED_IMPORT_OF_EXTENSION:
+ template: Imports of deferred libraries must hide all extensions.
+ tip: Try adding either a show combinator listing the names you need to reference or a hide combinator listing all of the extensions.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a library that is imported using
+ a deferred import declares an extension that is visible in the importing
+ library. Extension methods are resolved at compile time, and extensions
+ from deferred libraries aren't available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ Given a file (`a.dart`) that defines a named extension:
+
+ ```dart
+ %uri="lib/a.dart"
+ class C {}
+
+ extension E on String {
+ int get size => length;
+ }
+ ```
+
+ The following code produces this diagnostic because the named extension is
+ visible to the library:
+
+ ```dart
+ import [!'a.dart'!] deferred as a;
+
+ void f() {
+ a.C();
+ }
+ ```
+
+ #### Common fixes
+
+ If the library must be imported as `deferred`, then either add a `show`
+ clause listing the names being referenced or add a `hide` clause listing
+ all of the named extensions. Adding a `show` clause would look like this:
+
+ ```dart
+ import 'a.dart' deferred as a show C;
+
+ void f() {
+ a.C();
+ }
+ ```
+
+ Adding a `hide` clause would look like this:
+
+ ```dart
+ import 'a.dart' deferred as a hide E;
+
+ void f() {
+ a.C();
+ }
+ ```
+
+ With the first fix, the benefit is that if new extensions are added to the
+ imported library, then the extensions won't cause a diagnostic to be
+ generated.
+
+ If the library doesn't need to be imported as `deferred`, or if you need to
+ make use of the extension method declared in it, then remove the keyword
+ `deferred`:
+
+ ```dart
+ import 'a.dart' as a;
+
+ void f() {
+ a.C();
+ }
+ ```
+ DEFINITELY_UNASSIGNED_LATE_LOCAL_VARIABLE:
+ template: "The late local variable '{0}' is definitely unassigned at this point."
+ tip: Ensure that it is assigned on necessary execution paths.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the variable that is invalid
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when [definite assignment][] analysis
+ shows that a local variable that's marked as `late` is read before being
+ assigned.
+
+ #### Example
+
+ The following code produces this diagnostic because `x` wasn't assigned a
+ value before being read:
+
+ ```dart
+ void f(bool b) {
+ late int x;
+ print([!x!]);
+ }
+ ```
+
+ #### Common fixes
+
+ Assign a value to the variable before reading from it:
+
+ ```dart
+ void f(bool b) {
+ late int x;
+ x = b ? 1 : 0;
+ print(x);
+ }
+ ```
+ DISALLOWED_TYPE_INSTANTIATION_EXPRESSION:
+ template: Only a generic type, generic function, generic instance method, or generic constructor can be type instantiated.
+ tip: Try instantiating the type(s) of a generic type, generic function, generic instance method, or generic constructor.
+ comment: No parameters.
+ DUPLICATE_CONSTRUCTOR_NAME:
+ sharedName: DUPLICATE_CONSTRUCTOR
+ template: "The constructor with name '{0}' is already defined."
+ tip: Try renaming one of the constructors.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the duplicate entity
+ DUPLICATE_CONSTRUCTOR_DEFAULT:
+ sharedName: DUPLICATE_CONSTRUCTOR
+ template: The unnamed constructor is already defined.
+ tip: Try giving one of the constructors a name.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class declares more than one
+ unnamed constructor or when it declares more than one constructor with the
+ same name.
+
+ #### Examples
+
+ The following code produces this diagnostic because there are two
+ declarations for the unnamed constructor:
+
+ ```dart
+ class C {
+ C();
+
+ [!C!]();
+ }
+ ```
+
+ The following code produces this diagnostic because there are two
+ declarations for the constructor named `m`:
+
+ ```dart
+ class C {
+ C.m();
+
+ [!C.m!]();
+ }
+ ```
+
+ #### Common fixes
+
+ If there are multiple unnamed constructors and all of the constructors are
+ needed, then give all of them, or all except one of them, a name:
+
+ ```dart
+ class C {
+ C();
+
+ C.n();
+ }
+ ```
+
+ If there are multiple unnamed constructors and all except one of them are
+ unneeded, then remove the constructors that aren't needed:
+
+ ```dart
+ class C {
+ C();
+ }
+ ```
+
+ If there are multiple named constructors and all of the constructors are
+ needed, then rename all except one of them:
+
+ ```dart
+ class C {
+ C.m();
+
+ C.n();
+ }
+ ```
+
+ If there are multiple named constructors and all except one of them are
+ unneeded, then remove the constructorsthat aren't needed:
+
+ ```dart
+ class C {
+ C.m();
+ }
+ ```
+ DUPLICATE_DEFINITION:
+ template: "The name '{0}' is already defined."
+ tip: Try renaming one of the declarations.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the duplicate entity
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name is declared, and there is
+ a previous declaration with the same name in the same scope.
+
+ #### Examples
+
+ The following code produces this diagnostic because the name `x` is
+ declared twice:
+
+ ```dart
+ int x = 0;
+ int [!x!] = 1;
+ ```
+
+ #### Common fixes
+
+ Choose a different name for one of the declarations.
+
+ ```dart
+ int x = 0;
+ int y = 1;
+ ```
+ DUPLICATE_FIELD_FORMAL_PARAMETER:
+ template: "The field '{0}' can't be initialized by multiple parameters in the same constructor."
+ tip: Try removing one of the parameters, or using different fields.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the field
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when there's more than one field
+ formal parameter for the same field in a constructor's parameter list. It
+ isn't useful to assign a value that will immediately be overwritten.
+
+ #### Example
+
+ The following code produces this diagnostic because `this.f` appears twice
+ in the parameter list:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f, this.[!f!]) {}
+ }
+ ```
+
+ #### Common fixes
+
+ Remove one of the field formal parameters:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f) {}
+ }
+ ```
+ DUPLICATE_NAMED_ARGUMENT:
+ template: "The argument for the named parameter '{0}' was already specified."
+ tip: Try removing one of the named arguments, or correcting one of the names to reference a different named parameter.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the parameter that was duplicated
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an invocation has two or more
+ named arguments that have the same name.
+
+ #### Examples
+
+ The following code produces this diagnostic because there are two arguments
+ with the name `a`:
+
+ ```dart
+ %language=2.9
+ void f(C c) {
+ c.m(a: 0, [!a!]: 1);
+ }
+
+ class C {
+ void m({int a, int b}) {}
+ }
+ ```
+
+ #### Common fixes
+
+ If one of the arguments should have a different name, then change the name:
+
+ ```dart
+ %language=2.9
+ void f(C c) {
+ c.m(a: 0, b: 1);
+ }
+
+ class C {
+ void m({int a, int b}) {}
+ }
+ ```
+
+ If one of the arguments is wrong, then remove it:
+
+ ```dart
+ %language=2.9
+ void f(C c) {
+ c.m(a: 1);
+ }
+
+ class C {
+ void m({int a, int b}) {}
+ }
+ ```
+ DUPLICATE_PART:
+ template: "The library already contains a part with the URI '{0}'."
+ tip: Try removing all except one of the duplicated part directives.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the URI of the duplicate part
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a single file is referenced in
+ multiple part directives.
+
+ #### Example
+
+ Given a file named `part.dart` containing
+
+ ```dart
+ %uri="lib/part.dart"
+ part of lib;
+ ```
+
+ The following code produces this diagnostic because the file `part.dart` is
+ included multiple times:
+
+ ```dart
+ library lib;
+
+ part 'part.dart';
+ part [!'part.dart'!];
+ ```
+
+ #### Common fixes
+
+ Remove all except the first of the duplicated part directives:
+
+ ```dart
+ library lib;
+
+ part 'part.dart';
+ ```
+ ENUM_CONSTANT_SAME_NAME_AS_ENCLOSING:
+ template: "The name of the enum constant can't be the same as the enum's name."
+ tip: Try renaming the constant.
+ EQUAL_ELEMENTS_IN_CONST_SET:
+ template: "Two elements in a constant set literal can't be equal."
+ tip: Change or remove the duplicate element.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when two elements in a constant set
+ literal have the same value. The set can only contain each value once,
+ which means that one of the values is unnecessary.
+
+ #### Examples
+
+ The following code produces this diagnostic because the string `'a'` is
+ specified twice:
+
+ ```dart
+ const Set<String> set = {'a', [!'a'!]};
+ ```
+
+ #### Common fixes
+
+ Remove one of the duplicate values:
+
+ ```dart
+ const Set<String> set = {'a'};
+ ```
+
+ Note that literal sets preserve the order of their elements, so the choice
+ of which element to remove might affect the order in which elements are
+ returned by an iterator.
+ EQUAL_KEYS_IN_CONST_MAP:
+ template: "Two keys in a constant map literal can't be equal."
+ tip: Change or remove the duplicate key.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a key in a constant map is the
+ same as a previous key in the same map. If two keys are the same, then the
+ second value would overwrite the first value, which makes having both pairs
+ pointless.
+
+ #### Examples
+
+ The following code produces this diagnostic because the key `1` is used
+ twice:
+
+ ```dart
+ const map = <int, String>{1: 'a', 2: 'b', [!1!]: 'c', 4: 'd'};
+ ```
+
+ #### Common fixes
+
+ If both entries should be included in the map, then change one of the keys
+ to be different:
+
+ ```dart
+ const map = <int, String>{1: 'a', 2: 'b', 3: 'c', 4: 'd'};
+ ```
+
+ If only one of the entries is needed, then remove the one that isn't
+ needed:
+
+ ```dart
+ const map = <int, String>{1: 'a', 2: 'b', 4: 'd'};
+ ```
+
+ Note that literal maps preserve the order of their entries, so the choice
+ of which entry to remove might affect the order in which keys and values
+ are returned by an iterator.
+ EXPECTED_ONE_LIST_TYPE_ARGUMENTS:
+ template: "List literals require one type argument or none, but {0} found."
+ tip: Try adjusting the number of type arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the number of provided type arguments
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a list literal has more than one
+ type argument.
+
+ #### Example
+
+ The following code produces this diagnostic because the list literal has
+ two type arguments when it can have at most one:
+
+ ```dart
+ var l = [!<int, int>!][];
+ ```
+
+ #### Common fixes
+
+ Remove all except one of the type arguments:
+
+ ```dart
+ var l = <int>[];
+ ```
+ EXPECTED_ONE_SET_TYPE_ARGUMENTS:
+ template: "Set literals require one type argument or none, but {0} were found."
+ tip: Try adjusting the number of type arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the number of provided type arguments
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a set literal has more than one
+ type argument.
+
+ #### Example
+
+ The following code produces this diagnostic because the set literal has
+ three type arguments when it can have at most one:
+
+ ```dart
+ var s = [!<int, String, int>!]{0, 'a', 1};
+ ```
+
+ #### Common fixes
+
+ Remove all except one of the type arguments:
+
+ ```dart
+ var s = <int>{0, 1};
+ ```
+ EXPECTED_TWO_MAP_TYPE_ARGUMENTS:
+ template: "Map literals require two type arguments or none, but {0} found."
+ tip: Try adjusting the number of type arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the number of provided type arguments
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a map literal has either one or
+ more than two type arguments.
+
+ #### Example
+
+ The following code produces this diagnostic because the map literal has
+ three type arguments when it can have either two or zero:
+
+ ```dart
+ var m = [!<int, String, int>!]{};
+ ```
+
+ #### Common fixes
+
+ Remove all except two of the type arguments:
+
+ ```dart
+ var m = <int, String>{};
+ ```
+ EXPORT_INTERNAL_LIBRARY:
+ template: "The library '{0}' is internal and can't be exported."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the uri pointing to a library
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds an export whose `dart:`
+ URI references an internal library.
+
+ #### Example
+
+ The following code produces this diagnostic because `_interceptors` is an
+ internal library:
+
+ ```dart
+ export [!'dart:_interceptors'!];
+ ```
+
+ #### Common fixes
+
+ Remove the export directive.
+ EXPORT_LEGACY_SYMBOL:
+ template: "The symbol '{0}' is defined in a legacy library, and can't be re-exported from a library with null safety enabled."
+ tip: Try removing the export or migrating the legacy library.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of a symbol defined in a legacy library
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a library that was opted in to
+ null safety exports another library, and the exported library is opted out
+ of null safety.
+
+ #### Example
+
+ Given a library that is opted out of null safety:
+
+ ```dart
+ %uri="lib/optedOut.dart"
+ // @dart = 2.8
+ String s;
+ ```
+
+ The following code produces this diagnostic because it's exporting symbols
+ from an opted-out library:
+
+ ```dart
+ export [!'optedOut.dart'!];
+
+ class C {}
+ ```
+
+ #### Common fixes
+
+ If you're able to do so, migrate the exported library so that it doesn't
+ need to opt out:
+
+ ```dart
+ String? s;
+ ```
+
+ If you can't migrate the library, then remove the export:
+
+ ```dart
+ class C {}
+ ```
+
+ If the exported library (the one that is opted out) itself exports an
+ opted-in library, then it's valid for your library to indirectly export the
+ symbols from the opted-in library. You can do so by adding a hide
+ combinator to the export directive in your library that hides all of the
+ names declared in the opted-out library.
+ EXPORT_OF_NON_LIBRARY:
+ template: "The exported library '{0}' can't have a part-of directive."
+ tip: Try exporting the library that the part is a part of.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the uri pointing to a non-library declaration
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an export directive references a
+ part rather than a library.
+
+ #### Example
+
+ Given a file named `part.dart` containing
+
+ ```dart
+ %uri="lib/part.dart"
+ part of lib;
+ ```
+
+ The following code produces this diagnostic because the file `part.dart` is
+ a part, and only libraries can be exported:
+
+ ```dart
+ library lib;
+
+ export [!'part.dart'!];
+ ```
+
+ #### Common fixes
+
+ Either remove the export directive, or change the URI to be the URI of the
+ library containing the part.
+ EXPRESSION_IN_MAP:
+ template: "Expressions can't be used in a map literal."
+ tip: Try removing the expression or converting it to be a map entry.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the analyzer finds an
+ expression, rather than a map entry, in what appears to be a map literal.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ var map = <String, int>{'a': 0, 'b': 1, [!'c'!]};
+ ```
+
+ #### Common fixes
+
+ If the expression is intended to compute either a key or a value in an
+ entry, fix the issue by replacing the expression with the key or the value.
+ For example:
+
+ ```dart
+ var map = <String, int>{'a': 0, 'b': 1, 'c': 2};
+ ```
+ EXTENDS_NON_CLASS:
+ template: Classes can only extend other classes.
+ tip: Try specifying a different superclass, or removing the extends clause.
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name in the extends clause
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an `extends` clause contains a
+ name that is declared to be something other than a class.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` is declared to be a
+ function:
+
+ ```dart
+ void f() {}
+
+ class C extends [!f!] {}
+ ```
+
+ #### Common fixes
+
+ If you want the class to extend a class other than `Object`, then replace
+ the name in the `extends` clause with the name of that class:
+
+ ```dart
+ void f() {}
+
+ class C extends B {}
+
+ class B {}
+ ```
+
+ If you want the class to extend `Object`, then remove the `extends` clause:
+
+ ```dart
+ void f() {}
+
+ class C {}
+ ```
+ EXTENSION_AS_EXPRESSION:
+ template: "Extension '{0}' can't be used as an expression."
+ tip: Try replacing it with a valid expression.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the extension
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name of an extension is used
+ in an expression other than in an extension override or to qualify an
+ access to a static member of the extension. Because classes define a type,
+ the name of a class can be used to refer to the instance of `Type`
+ representing the type of the class. Extensions, on the other hand, don't
+ define a type and can't be used as a type literal.
+
+ #### Examples
+
+ The following code produces this diagnostic because `E` is an extension:
+
+ ```dart
+ extension E on int {
+ static String m() => '';
+ }
+
+ var x = [!E!];
+ ```
+
+ #### Common fixes
+
+ Replace the name of the extension with a name that can be referenced, such
+ as a static member defined on the extension:
+
+ ```dart
+ extension E on int {
+ static String m() => '';
+ }
+
+ var x = E.m();
+ ```
+ EXTENSION_CONFLICTING_STATIC_AND_INSTANCE:
+ template: "Extension '{0}' can't define static member '{1}' and an instance member with the same name."
+ tip: "Try renaming the member to a name that doesn't conflict."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the extension defining the conflicting member
+ 1: the name of the conflicting static member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension declaration
+ contains both an instance member and a static member that have the same
+ name. The instance member and the static member can't have the same name
+ because it's unclear which member is being referenced by an unqualified use
+ of the name within the body of the extension.
+
+ #### Examples
+
+ The following code produces this diagnostic because the name `a` is being
+ used for two different members:
+
+ ```dart
+ extension E on Object {
+ int get a => 0;
+ static int [!a!]() => 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Rename or remove one of the members:
+
+ ```dart
+ extension E on Object {
+ int get a => 0;
+ static int b() => 0;
+ }
+ ```
+ EXTENSION_DECLARES_MEMBER_OF_OBJECT:
+ template: "Extensions can't declare members with the same name as a member declared by 'Object'."
+ tip: Try specifying a different name for the member.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension declaration
+ declares a member with the same name as a member declared in the class
+ `Object`. Such a member can never be used because the member in `Object` is
+ always found first.
+
+ #### Examples
+
+ The following code produces this diagnostic because `toString` is defined
+ by `Object`:
+
+ ```dart
+ extension E on String {
+ String [!toString!]() => this;
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the member or rename it so that the name doesn't conflict with the
+ member in `Object`:
+
+ ```dart
+ extension E on String {
+ String displayString() => this;
+ }
+ ```
+ EXTENSION_OVERRIDE_ACCESS_TO_STATIC_MEMBER:
+ template: "An extension override can't be used to access a static member from an extension."
+ tip: Try using just the name of the extension.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override is the
+ receiver of the invocation of a static member. Similar to static members in
+ classes, the static members of an extension should be accessed using the
+ name of the extension, not an extension override.
+
+ #### Examples
+
+ The following code produces this diagnostic because `m` is static:
+
+ ```dart
+ extension E on String {
+ static void m() {}
+ }
+
+ void f() {
+ E('').[!m!]();
+ }
+ ```
+
+ #### Common fixes
+
+ Replace the extension override with the name of the extension:
+
+ ```dart
+ extension E on String {
+ static void m() {}
+ }
+
+ void f() {
+ E.m();
+ }
+ ```
+ EXTENSION_OVERRIDE_ARGUMENT_NOT_ASSIGNABLE:
+ template: "The type of the argument to the extension override '{0}' isn't assignable to the extended type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the argument
+ 1: the extended type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the argument to an extension
+ override isn't assignable to the type being extended by the extension.
+
+ #### Examples
+
+ The following code produces this diagnostic because `3` isn't a `String`:
+
+ ```dart
+ extension E on String {
+ void method() {}
+ }
+
+ void f() {
+ E([!3!]).method();
+ }
+ ```
+
+ #### Common fixes
+
+ If you're using the correct extension, then update the argument to have the
+ correct type:
+
+ ```dart
+ extension E on String {
+ void method() {}
+ }
+
+ void f() {
+ E(3.toString()).method();
+ }
+ ```
+
+ If there's a different extension that's valid for the type of the argument,
+ then either replace the name of the extension or unwrap the argument so
+ that the correct extension is found.
+ EXTENSION_OVERRIDE_WITHOUT_ACCESS:
+ template: An extension override can only be used to access instance members.
+ tip: Consider adding an access to an instance member.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override is found
+ that isn't being used to access one of the members of the extension. The
+ extension override syntax doesn't have any runtime semantics; it only
+ controls which member is selected at compile time.
+
+ #### Examples
+
+ The following code produces this diagnostic because `E(i)` isn't an
+ expression:
+
+ ```dart
+ extension E on int {
+ int get a => 0;
+ }
+
+ void f(int i) {
+ print([!E(i)!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If you want to invoke one of the members of the extension, then add the
+ invocation:
+
+ ```dart
+ extension E on int {
+ int get a => 0;
+ }
+
+ void f(int i) {
+ print(E(i).a);
+ }
+ ```
+
+ If you don't want to invoke a member, then unwrap the argument:
+
+ ```dart
+ extension E on int {
+ int get a => 0;
+ }
+
+ void f(int i) {
+ print(i);
+ }
+ ```
+ EXTENSION_OVERRIDE_WITH_CASCADE:
+ template: "Extension overrides have no value so they can't be used as the receiver of a cascade expression."
+ tip: "Try using '.' instead of '..'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override is used as
+ the receiver of a cascade expression. The value of a cascade expression
+ `e..m` is the value of the receiver `e`, but extension overrides aren't
+ expressions and don't have a value.
+
+ #### Examples
+
+ The following code produces this diagnostic because `E(3)` isn't an
+ expression:
+
+ ```dart
+ extension E on int {
+ void m() {}
+ }
+ f() {
+ [!E!](3)..m();
+ }
+ ```
+
+ #### Common fixes
+
+ Use `.` rather than `..`:
+
+ ```dart
+ extension E on int {
+ void m() {}
+ }
+ f() {
+ E(3).m();
+ }
+ ```
+
+ If there are multiple cascaded accesses, you'll need to duplicate the
+ extension override for each one.
+ EXTERNAL_FIELD_CONSTRUCTOR_INITIALIZER:
+ template: External fields cannot have initializers.
+ tip: "Try removing the field initializer or the 'external' keyword from the field declaration."
+ EXTERNAL_FIELD_INITIALIZER:
+ template: External fields cannot have initializers.
+ tip: "Try removing the initializer or the 'external' keyword."
+ EXTERNAL_VARIABLE_INITIALIZER:
+ template: External variables cannot have initializers.
+ tip: "Try removing the initializer or the 'external' keyword."
+ EXTRA_POSITIONAL_ARGUMENTS:
+ template: "Too many positional arguments: {0} expected, but {1} found."
+ tip: Try removing the extra arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the maximum number of positional arguments
+ 1: the actual number of positional arguments given
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function invocation
+ has more positional arguments than the method or function allows.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` defines 2
+ parameters but is invoked with 3 arguments:
+
+ ```dart
+ void f(int a, int b) {}
+ void g() {
+ f(1, 2, [!3!]);
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the arguments that don't correspond to parameters:
+
+ ```dart
+ void f(int a, int b) {}
+ void g() {
+ f(1, 2);
+ }
+ ```
+ EXTRA_POSITIONAL_ARGUMENTS_COULD_BE_NAMED:
+ template: "Too many positional arguments: {0} expected, but {1} found."
+ tip: Try removing the extra positional arguments, or specifying the name for named arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the maximum number of positional arguments
+ 1: the actual number of positional arguments given
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function invocation
+ has more positional arguments than the method or function allows, but the
+ method or function defines named parameters.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` defines 2
+ positional parameters but has a named parameter that could be used for the
+ third argument:
+
+ ```dart
+ %language=2.9
+ void f(int a, int b, {int c}) {}
+ void g() {
+ f(1, 2, [!3!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If some of the arguments should be values for named parameters, then add
+ the names before the arguments:
+
+ ```dart
+ %language=2.9
+ void f(int a, int b, {int c}) {}
+ void g() {
+ f(1, 2, c: 3);
+ }
+ ```
+
+ Otherwise, remove the arguments that don't correspond to positional
+ parameters:
+
+ ```dart
+ %language=2.9
+ void f(int a, int b, {int c}) {}
+ void g() {
+ f(1, 2);
+ }
+ ```
+ FIELD_INITIALIZED_BY_MULTIPLE_INITIALIZERS:
+ template: "The field '{0}' can't be initialized twice in the same constructor."
+ tip: Try removing one of the initializations.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the field being initialized multiple times
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the initializer list of a
+ constructor initializes a field more than once. There is no value to allow
+ both initializers because only the last value is preserved.
+
+ #### Example
+
+ The following code produces this diagnostic because the field `f` is being
+ initialized twice:
+
+ ```dart
+ class C {
+ int f;
+
+ C() : f = 0, [!f!] = 1;
+ }
+ ```
+
+ #### Common fixes
+
+ Remove one of the initializers:
+
+ ```dart
+ class C {
+ int f;
+
+ C() : f = 0;
+ }
+ ```
+ FIELD_INITIALIZED_IN_INITIALIZER_AND_DECLARATION:
+ template: "Fields can't be initialized in the constructor if they are final and were already initialized at their declaration."
+ tip: Try removing one of the initializations.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a final field is initialized in
+ both the declaration of the field and in an initializer in a constructor.
+ Final fields can only be assigned once, so it can't be initialized in both
+ places.
+
+ #### Example
+
+ The following code produces this diagnostic because `f` is :
+
+ ```dart
+ class C {
+ final int f = 0;
+ C() : [!f!] = 1;
+ }
+ ```
+
+ #### Common fixes
+
+ If the initialization doesn't depend on any values passed to the
+ constructor, and if all of the constructors need to initialize the field to
+ the same value, then remove the initializer from the constructor:
+
+ ```dart
+ class C {
+ final int f = 0;
+ C();
+ }
+ ```
+
+ If the initialization depends on a value passed to the constructor, or if
+ different constructors need to initialize the field differently, then
+ remove the initializer in the field's declaration:
+
+ ```dart
+ class C {
+ final int f;
+ C() : f = 1;
+ }
+ ```
+ FIELD_INITIALIZED_IN_PARAMETER_AND_INITIALIZER:
+ template: "Fields can't be initialized in both the parameter list and the initializers."
+ tip: Try removing one of the initializations.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a field is initialized in both
+ the parameter list and in the initializer list of a constructor.
+
+ #### Example
+
+ The following code produces this diagnostic because the field `f` is
+ initialized both by a field formal parameter and in the initializer list:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f) : [!f!] = 0;
+ }
+ ```
+
+ #### Common fixes
+
+ If the field should be initialized by the parameter, then remove the
+ initialization in the initializer list:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f);
+ }
+ ```
+
+ If the field should be initialized in the initializer list and the
+ parameter isn't needed, then remove the parameter:
+
+ ```dart
+ class C {
+ int f;
+
+ C() : f = 0;
+ }
+ ```
+
+ If the field should be initialized in the initializer list and the
+ parameter is needed, then make it a normal parameter:
+
+ ```dart
+ class C {
+ int f;
+
+ C(int g) : f = g * 2;
+ }
+ ```
+ FIELD_INITIALIZER_FACTORY_CONSTRUCTOR:
+ template: "Initializing formal parameters can't be used in factory constructors."
+ tip: Try using a normal parameter.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a factory constructor has a
+ field formal parameter. Factory constructors can't assign values to fields
+ because no instance is created; hence, there is no field to assign.
+
+ #### Example
+
+ The following code produces this diagnostic because the factory constructor
+ uses a field formal parameter:
+
+ ```dart
+ class C {
+ int? f;
+
+ factory C([!this.f!]) => throw 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Replace the field formal parameter with a normal parameter:
+
+ ```dart
+ class C {
+ int? f;
+
+ factory C(int f) => throw 0;
+ }
+ ```
+ FIELD_INITIALIZER_NOT_ASSIGNABLE:
+ template: "The initializer type '{0}' can't be assigned to the field type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type of the initializer expression
+ 1: the name of the type of the field
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the initializer list of a
+ constructor initializes a field to a value that isn't assignable to the
+ field.
+
+ #### Example
+
+ The following code produces this diagnostic because `0` has the type `int`,
+ and an `int` can't be assigned to a field of type `String`:
+
+ ```dart
+ class C {
+ String s;
+
+ C() : s = [!0!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the type of the field is correct, then change the value assigned to it
+ so that the value has a valid type:
+
+ ```dart
+ class C {
+ String s;
+
+ C() : s = '0';
+ }
+ ```
+
+ If the type of the value is correct, then change the type of the field to
+ allow the assignment:
+
+ ```dart
+ class C {
+ int s;
+
+ C() : s = 0;
+ }
+ ```
+ CONST_FIELD_INITIALIZER_NOT_ASSIGNABLE:
+ sharedName: FIELD_INITIALIZER_NOT_ASSIGNABLE
+ template: "The initializer type '{0}' can't be assigned to the field type '{1}' in a const constructor."
+ tip: "Try using a subtype, or removing the 'const' keyword"
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type of the initializer expression
+ 1: the name of the type of the field
+ FIELD_INITIALIZER_OUTSIDE_CONSTRUCTOR:
+ template: Initializing formal parameters can only be used in constructors.
+ tip: Try using a normal parameter.
+ comment: |-
+ 7.6.1 Generative Constructors: It is a compile-time error if an
+ initializing formal is used by a function other than a non-redirecting
+ generative constructor.
+ FIELD_INITIALIZER_REDIRECTING_CONSTRUCTOR:
+ template: "The redirecting constructor can't have a field initializer."
+ tip: Try initializing the field in the constructor being redirected to.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a redirecting constructor
+ initializes a field in the object. This isn't allowed because the instance
+ that has the field hasn't been created at the point at which it should be
+ initialized.
+
+ #### Example
+
+ The following code produces this diagnostic because the constructor
+ `C.zero`, which redirects to the constructor `C`, has a field formal
+ parameter that initializes the field `f`:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f);
+
+ C.zero([!this.f!]) : this(f);
+ }
+ ```
+
+ The following code produces this diagnostic because the constructor
+ `C.zero`, which redirects to the constructor `C`, has an initializer that
+ initializes the field `f`:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f);
+
+ C.zero() : [!f = 0!], this(1);
+ }
+ ```
+
+ #### Common fixes
+
+ If the initialization is done by a field formal parameter, then use a
+ normal parameter:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f);
+
+ C.zero(int f) : this(f);
+ }
+ ```
+
+ If the initialization is done in an initializer, then remove the
+ initializer:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f);
+
+ C.zero() : this(0);
+ }
+ ```
+ FIELD_INITIALIZING_FORMAL_NOT_ASSIGNABLE:
+ template: "The parameter type '{0}' is incompatible with the field type '{1}'."
+ tip: "Try changing or removing the parameter's type, or changing the field's type."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type of the field formal parameter
+ 1: the name of the type of the field
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type of a field formal
+ parameter isn't assignable to the type of the field being initialized.
+
+ #### Example
+
+ The following code produces this diagnostic because the field formal
+ parameter has the type `String`, but the type of the field is `int`. The
+ parameter must have a type that is a subtype of the field's type.
+
+ ```dart
+ class C {
+ int f;
+
+ C([!String this.f!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If the type of the field is incorrect, then change the type of the field to
+ match the type of the parameter, and consider removing the type from the
+ parameter:
+
+ ```dart
+ class C {
+ String f;
+
+ C(this.f);
+ }
+ ```
+
+ If the type of the parameter is incorrect, then remove the type of the
+ parameter:
+
+ ```dart
+ class C {
+ int f;
+
+ C(this.f);
+ }
+ ```
+
+ If the types of both the field and the parameter are correct, then use an
+ initializer rather than a field formal parameter to convert the parameter
+ value into a value of the correct type:
+
+ ```dart
+ class C {
+ int f;
+
+ C(String s) : f = int.parse(s);
+ }
+ ```
+ FINAL_INITIALIZED_IN_DECLARATION_AND_CONSTRUCTOR:
+ template: "'{0}' is final and was given a value when it was declared, so it can't be set to a new value."
+ tip: Try removing one of the initializations.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the field in question
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a final field is initialized
+ twice: once where it's declared and once by a constructor's parameter.
+
+ #### Example
+
+ The following code produces this diagnostic because the field `f` is
+ initialized twice:
+
+ ```dart
+ class C {
+ final int f = 0;
+
+ C(this.[!f!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If the field should have the same value for all instances, then remove the
+ initialization in the parameter list:
+
+ ```dart
+ class C {
+ final int f = 0;
+
+ C();
+ }
+ ```
+
+ If the field can have different values in different instances, then remove
+ the initialization in the declaration:
+
+ ```dart
+ class C {
+ final int f;
+
+ C(this.f);
+ }
+ ```
+ FINAL_NOT_INITIALIZED:
+ template: "The final variable '{0}' must be initialized."
+ tip: Try initializing the variable.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the uninitialized final variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a final field or variable isn't
+ initialized.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` doesn't have an
+ initializer:
+
+ ```dart
+ final [!x!];
+ ```
+
+ #### Common fixes
+
+ For variables and static fields, you can add an initializer:
+
+ ```dart
+ final x = 0;
+ ```
+
+ For instance fields, you can add an initializer as shown in the previous
+ example, or you can initialize the field in every constructor. You can
+ initialize the field by using a field formal parameter:
+
+ ```dart
+ class C {
+ final int x;
+ C(this.x);
+ }
+ ```
+
+ You can also initialize the field by using an initializer in the
+ constructor:
+
+ ```dart
+ class C {
+ final int x;
+ C(int y) : x = y * 2;
+ }
+ ```
+ FINAL_NOT_INITIALIZED_CONSTRUCTOR_1:
+ sharedName: FINAL_NOT_INITIALIZED_CONSTRUCTOR
+ template: "All final variables must be initialized, but '{0}' isn't."
+ tip: Try adding an initializer for the field.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the uninitialized final variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class defines one or more
+ final instance fields without initializers and has at least one constructor
+ that doesn't initialize those fields. All final instance fields must be
+ initialized when the instance is created, either by the field's initializer
+ or by the constructor.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ class C {
+ final String value;
+
+ [!C!]();
+ }
+ ```
+
+ #### Common fixes
+
+ If the value should be passed in to the constructor directly, then use a
+ field formal parameter to initialize the field `value`:
+
+ ```dart
+ class C {
+ final String value;
+
+ C(this.value);
+ }
+ ```
+
+ If the value should be computed indirectly from a value provided by the
+ caller, then add a parameter and include an initializer:
+
+ ```dart
+ class C {
+ final String value;
+
+ C(Object o) : value = o.toString();
+ }
+ ```
+
+ If the value of the field doesn't depend on values that can be passed to
+ the constructor, then add an initializer for the field as part of the field
+ declaration:
+
+ ```dart
+ class C {
+ final String value = '';
+
+ C();
+ }
+ ```
+
+ If the value of the field doesn't depend on values that can be passed to
+ the constructor but different constructors need to initialize it to
+ different values, then add an initializer for the field in the initializer
+ list:
+
+ ```dart
+ class C {
+ final String value;
+
+ C() : value = '';
+
+ C.named() : value = 'c';
+ }
+ ```
+
+ However, if the value is the same for all instances, then consider using a
+ static field instead of an instance field:
+
+ ```dart
+ class C {
+ static const String value = '';
+
+ C();
+ }
+ ```
+ FINAL_NOT_INITIALIZED_CONSTRUCTOR_2:
+ sharedName: FINAL_NOT_INITIALIZED_CONSTRUCTOR
+ template: "All final variables must be initialized, but '{0}' and '{1}' aren't."
+ tip: Try adding initializers for the fields.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the uninitialized final variable
+ 1: the name of the uninitialized final variable
+ FINAL_NOT_INITIALIZED_CONSTRUCTOR_3_PLUS:
+ sharedName: FINAL_NOT_INITIALIZED_CONSTRUCTOR
+ template: "All final variables must be initialized, but '{0}', '{1}', and {2} others aren't."
+ tip: Try adding initializers for the fields.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the uninitialized final variable
+ 1: the name of the uninitialized final variable
+ 2: the number of additional not initialized variables that aren't listed
+ FOR_IN_OF_INVALID_ELEMENT_TYPE:
+ template: "The type '{0}' used in the 'for' loop must implement '{1}' with a type argument that can be assigned to '{2}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the iterable expression.
+ 1: the sequence type -- Iterable for `for` or Stream for `await for`.
+ 2: the loop variable type.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the `Iterable` or `Stream` in a
+ for-in loop has an element type that can't be assigned to the loop
+ variable.
+
+ #### Example
+
+ The following code produces this diagnostic because `<String>[]` has an
+ element type of `String`, and `String` can't be assigned to the type of `e`
+ (`int`):
+
+ ```dart
+ void f() {
+ for (int e in [!<String>[]!]) {
+ print(e);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the type of the loop variable is correct, then update the type of the
+ iterable:
+
+ ```dart
+ void f() {
+ for (int e in <int>[]) {
+ print(e);
+ }
+ }
+ ```
+
+ If the type of the iterable is correct, then update the type of the loop
+ variable:
+
+ ```dart
+ void f() {
+ for (String e in <String>[]) {
+ print(e);
+ }
+ }
+ ```
+ FOR_IN_OF_INVALID_TYPE:
+ template: "The type '{0}' used in the 'for' loop must implement {1}."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the iterable expression.
+ 1: the sequence type -- Iterable for `for` or Stream for `await for`.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the expression following `in` in
+ a for-in loop has a type that isn't a subclass of `Iterable`.
+
+ #### Examples
+
+ The following code produces this diagnostic because `m` is a `Map`, and
+ `Map` isn't a subclass of `Iterable`:
+
+ ```dart
+ void f(Map<String, String> m) {
+ for (String s in [!m!]) {
+ print(s);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Replace the expression with one that produces an iterable value:
+
+ ```dart
+ void f(Map<String, String> m) {
+ for (String s in m.values) {
+ print(s);
+ }
+ }
+ ```
+ FOR_IN_WITH_CONST_VARIABLE:
+ template: "A for-in loop variable can't be a 'const'."
+ tip: "Try removing the 'const' modifier from the variable, or use a different variable."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the loop variable declared in a
+ for-in loop is declared to be a `const`. The variable can't be a `const`
+ because the value can't be computed at compile time.
+
+ #### Example
+
+ The following code produces this diagnostic because the loop variable `x`
+ is declared to be a `const`:
+
+ ```dart
+ void f() {
+ for ([!const!] x in [0, 1, 2]) {
+ print(x);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If there's a type annotation, then remove the `const` modifier from the
+ declaration.
+
+ If there's no type, then replace the `const` modifier with `final`, `var`,
+ or a type annotation:
+
+ ```dart
+ void f() {
+ for (final x in [0, 1, 2]) {
+ print(x);
+ }
+ }
+ ```
+ GENERIC_FUNCTION_TYPE_CANNOT_BE_BOUND:
+ template: "Generic function types can't be used as type parameter bounds"
+ tip: Try making the free variable in the function type part of the larger declaration signature
+ comment: |-
+ It is a compile-time error if a generic function type is used as a bound
+ for a formal type parameter of a class or a function.
+ GENERIC_FUNCTION_TYPE_CANNOT_BE_TYPE_ARGUMENT:
+ template: "A generic function type can't be a type argument."
+ tip: "Try removing type parameters from the generic function type, or using 'dynamic' as the type argument here."
+ comment: |-
+ It is a compile-time error if a generic function type is used as an actual
+ type argument.
+ GENERIC_METHOD_TYPE_INSTANTIATION_ON_DYNAMIC:
+ template: "A method tear-off on a receiver whose type is 'dynamic' can't have type arguments."
+ tip: Specify the type of the receiver, or remove the type arguments from the method tear-off.
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an instance method is being torn
+ off from a receiver whose type is `dynamic`, and the tear-off includes type
+ arguments. Because the analyzer can't know how many type parameters the
+ method has, or whether it has any type parameters, there's no way it can
+ validate that the type arguments are correct. As a result, the type
+ arguments aren't allowed.
+
+ #### Example
+
+ The following code produces this diagnostic because the type of `p` is
+ `dynamic` and the tear-off of `m` has type arguments:
+
+ ```dart
+ void f(dynamic list) {
+ [!list.fold!]<int>;
+ }
+ ```
+
+ #### Common fixes
+
+ If you can use a more specific type than `dynamic`, then change the type of
+ the receiver:
+
+ ```dart
+ void f(List<Object> list) {
+ list.fold<int>;
+ }
+ ```
+
+ If you can't use a more specific type, then remove the type arguments:
+
+ ```dart
+ void f(dynamic list) {
+ list.cast;
+ }
+ ```
+ GETTER_NOT_ASSIGNABLE_SETTER_TYPES:
+ template: "The return type of getter '{0}' is '{1}' which isn't assignable to the type '{2}' of its setter '{3}'."
+ tip: Try changing the types so that they are compatible.
+ comment: |-
+ Parameters:
+ 0: the name of the getter
+ 1: the type of the getter
+ 2: the type of the setter
+ 3: the name of the setter
+ GETTER_NOT_SUBTYPE_SETTER_TYPES:
+ template: "The return type of getter '{0}' is '{1}' which isn't a subtype of the type '{2}' of its setter '{3}'."
+ tip: Try changing the types so that they are compatible.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the getter
+ 1: the type of the getter
+ 2: the type of the setter
+ 3: the name of the setter
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the return type of a getter
+ isn't a subtype of the type of the parameter of a setter with the same
+ name.
+
+ The subtype relationship is a requirement whether the getter and setter are
+ in the same class or whether one of them is in a superclass of the other.
+
+ #### Example
+
+ The following code produces this diagnostic because the return type of the
+ getter `x` is `num`, the parameter type of the setter `x` is `int`, and
+ `num` isn't a subtype of `int`:
+
+ ```dart
+ class C {
+ num get [!x!] => 0;
+
+ set x(int y) {}
+ }
+ ```
+
+ #### Common fixes
+
+ If the type of the getter is correct, then change the type of the setter:
+
+ ```dart
+ class C {
+ num get x => 0;
+
+ set x(num y) {}
+ }
+ ```
+
+ If the type of the setter is correct, then change the type of the getter:
+
+ ```dart
+ class C {
+ int get x => 0;
+
+ set x(int y) {}
+ }
+ ```
+ IF_ELEMENT_CONDITION_FROM_DEFERRED_LIBRARY:
+ template: "Constant values from a deferred library can't be used as values in an if condition inside a const collection literal."
+ tip: Try making the deferred import non-deferred.
+ ILLEGAL_ASYNC_GENERATOR_RETURN_TYPE:
+ template: "Functions marked 'async*' must have a return type that is a supertype of 'Stream<T>' for some type 'T'."
+ tip: "Try fixing the return type of the function, or removing the modifier 'async*' from the function body."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the body of a function has the
+ `async*` modifier even though the return type of the function isn't either
+ `Stream` or a supertype of `Stream`.
+
+ #### Example
+
+ The following code produces this diagnostic because the body of the
+ function `f` has the 'async*' modifier even though the return type `int`
+ isn't a supertype of `Stream`:
+
+ ```dart
+ [!int!] f() async* {}
+ ```
+
+ #### Common fixes
+
+ If the function should be asynchronous, then change the return type to be
+ either `Stream` or a supertype of `Stream`:
+
+ ```dart
+ Stream<int> f() async* {}
+ ```
+
+ If the function should be synchronous, then remove the `async*` modifier:
+
+ ```dart
+ int f() => 0;
+ ```
+ ILLEGAL_ASYNC_RETURN_TYPE:
+ template: "Functions marked 'async' must have a return type assignable to 'Future'."
+ tip: "Try fixing the return type of the function, or removing the modifier 'async' from the function body."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the body of a function has the
+ `async` modifier even though the return type of the function isn't
+ assignable to `Future`.
+
+ #### Example
+
+ The following code produces this diagnostic because the body of the
+ function `f` has the `async` modifier even though the return type isn't
+ assignable to `Future`:
+
+ ```dart
+ [!int!] f() async {
+ return 0;
+ }
+ ```
+
+ #### Common fixes
+
+ If the function should be asynchronous, then change the return type to be
+ assignable to `Future`:
+
+ ```dart
+ Future<int> f() async {
+ return 0;
+ }
+ ```
+
+ If the function should be synchronous, then remove the `async` modifier:
+
+ ```dart
+ int f() => 0;
+ ```
+ ILLEGAL_SYNC_GENERATOR_RETURN_TYPE:
+ template: "Functions marked 'sync*' must have a return type that is a supertype of 'Iterable<T>' for some type 'T'."
+ tip: "Try fixing the return type of the function, or removing the modifier 'sync*' from the function body."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the body of a function has the
+ `sync*` modifier even though the return type of the function isn't either
+ `Iterable` or a supertype of `Iterable`.
+
+ #### Example
+
+ The following code produces this diagnostic because the body of the
+ function `f` has the 'sync*' modifier even though the return type `int`
+ isn't a supertype of `Iterable`:
+
+ ```dart
+ [!int!] f() sync* {}
+ ```
+
+ #### Common fixes
+
+ If the function should return an iterable, then change the return type to
+ be either `Iterable` or a supertype of `Iterable`:
+
+ ```dart
+ Iterable<int> f() sync* {}
+ ```
+
+ If the function should return a single value, then remove the `sync*`
+ modifier:
+
+ ```dart
+ int f() => 0;
+ ```
+ IMPLEMENTS_NON_CLASS:
+ template: Classes and mixins can only implement other classes and mixins.
+ tip: Try specifying a class or mixin, or remove the name from the list.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the interface that was not found
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name used in the `implements`
+ clause of a class or mixin declaration is defined to be something other
+ than a class or mixin.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` is a variable
+ rather than a class or mixin:
+
+ ```dart
+ var x;
+ class C implements [!x!] {}
+ ```
+
+ #### Common fixes
+
+ If the name is the name of an existing class or mixin that's already being
+ imported, then add a prefix to the import so that the local definition of
+ the name doesn't shadow the imported name.
+
+ If the name is the name of an existing class or mixin that isn't being
+ imported, then add an import, with a prefix, for the library in which it’s
+ declared.
+
+ Otherwise, either replace the name in the `implements` clause with the name
+ of an existing class or mixin, or remove the name from the `implements`
+ clause.
+ IMPLEMENTS_REPEATED:
+ template: "'{0}' can only be implemented once."
+ tip: Try removing all but one occurrence of the class name.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the interface that is implemented more than once
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a single class is specified more
+ than once in an `implements` clause.
+
+ #### Examples
+
+ The following code produces this diagnostic because `A` is in the list
+ twice:
+
+ ```dart
+ class A {}
+ class B implements A, [!A!] {}
+ ```
+
+ #### Common fixes
+
+ Remove all except one occurrence of the class name:
+
+ ```dart
+ class A {}
+ class B implements A {}
+ ```
+ IMPLEMENTS_SUPER_CLASS:
+ template: "'{0}' can't be used in both the 'extends' and 'implements' clauses."
+ tip: Try removing one of the occurrences.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the class that appears in both "extends" and "implements"
+ clauses
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when one class is listed in both the
+ `extends` and `implements` clauses of another class.
+
+ #### Example
+
+ The following code produces this diagnostic because the class `A` is used
+ in both the `extends` and `implements` clauses for the class `B`:
+
+ ```dart
+ class A {}
+
+ class B extends A implements [!A!] {}
+ ```
+
+ #### Common fixes
+
+ If you want to inherit the implementation from the class, then remove the
+ class from the `implements` clause:
+
+ ```dart
+ class A {}
+
+ class B extends A {}
+ ```
+
+ If you don't want to inherit the implementation from the class, then remove
+ the `extends` clause:
+
+ ```dart
+ class A {}
+
+ class B implements A {}
+ ```
+ IMPLICIT_THIS_REFERENCE_IN_INITIALIZER:
+ template: "The instance member '{0}' can't be accessed in an initializer."
+ tip: Try replacing the reference to the instance member with a different expression
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the instance member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds a reference to an
+ instance member in a constructor's initializer list.
+
+ #### Examples
+
+ The following code produces this diagnostic because `defaultX` is an
+ instance member:
+
+ ```dart
+ class C {
+ int x;
+
+ C() : x = [!defaultX!];
+
+ int get defaultX => 0;
+ }
+ ```
+
+ #### Common fixes
+
+ If the member can be made static, then do so:
+
+ ```dart
+ class C {
+ int x;
+
+ C() : x = defaultX;
+
+ static int get defaultX => 0;
+ }
+ ```
+
+ If not, then replace the reference in the initializer with a different
+ expression that doesn't use an instance member:
+
+ ```dart
+ class C {
+ int x;
+
+ C() : x = 0;
+
+ int get defaultX => 0;
+ }
+ ```
+ IMPORT_INTERNAL_LIBRARY:
+ template: "The library '{0}' is internal and can't be imported."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the uri pointing to a library
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds an import whose `dart:`
+ URI references an internal library.
+
+ #### Example
+
+ The following code produces this diagnostic because `_interceptors` is an
+ internal library:
+
+ ```dart
+ import [!'dart:_interceptors'!];
+ ```
+
+ #### Common fixes
+
+ Remove the import directive.
+ IMPORT_OF_NON_LIBRARY:
+ template: "The imported library '{0}' can't have a part-of directive."
+ tip: Try importing the library that the part is a part of.
+ comment: |-
+ 14.1 Imports: It is a compile-time error if the specified URI of an
+ immediate import does not refer to a library declaration.
+
+ Parameters:
+ 0: the uri pointing to a non-library declaration
+ INCONSISTENT_CASE_EXPRESSION_TYPES:
+ template: "Case expressions must have the same types, '{0}' isn't a '{1}'."
+ comment: |-
+ 13.9 Switch: It is a compile-time error if values of the expressions
+ <i>e<sub>k</sub></i> are not instances of the same class <i>C</i>, for all
+ <i>1 <= k <= n</i>.
+
+ Parameters:
+ 0: the expression source code that is the unexpected type
+ 1: the name of the expected type
+ INCONSISTENT_INHERITANCE:
+ template: "Superinterfaces don't have a valid override for '{0}': {1}."
+ tip: Try adding an explicit override that is consistent with all of the inherited members.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the instance member with inconsistent inheritance.
+ 1: the list of all inherited signatures for this member.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class inherits two or more
+ conflicting signatures for a member and doesn't provide an implementation
+ that satisfies all the inherited signatures.
+
+ #### Example
+
+ The following code produces this diagnostic because `C` is inheriting the
+ declaration of `m` from `A`, and that implementation isn't consistent with
+ the signature of `m` that's inherited from `B`:
+
+ ```dart
+ %language=2.9
+ class A {
+ void m({int a}) {}
+ }
+
+ class B {
+ void m({int b}) {}
+ }
+
+ class [!C!] extends A implements B {
+ }
+ ```
+
+ #### Common fixes
+
+ Add an implementation of the method that satisfies all the inherited
+ signatures:
+
+ ```dart
+ %language=2.9
+ class A {
+ void m({int a}) {}
+ }
+
+ class B {
+ void m({int b}) {}
+ }
+
+ class C extends A implements B {
+ void m({int a, int b}) {}
+ }
+ ```
+ INCONSISTENT_INHERITANCE_GETTER_AND_METHOD:
+ template: "'{0}' is inherited as a getter (from '{1}') and also a method (from '{2}')."
+ tip: Try adjusting the supertypes of this class to remove the inconsistency.
+ comment: |-
+ 11.1.1 Inheritance and Overriding. Let `I` be the implicit interface of a
+ class `C` declared in library `L`. `I` inherits all members of
+ `inherited(I, L)` and `I` overrides `m'` if `m' ∈ overrides(I, L)`. It is
+ a compile-time error if `m` is a method and `m'` is a getter, or if `m`
+ is a getter and `m'` is a method.
+
+ Parameters:
+ 0: the name of the the instance member with inconsistent inheritance.
+ 1: the name of the superinterface that declares the name as a getter.
+ 2: the name of the superinterface that declares the name as a method.
+ INCONSISTENT_LANGUAGE_VERSION_OVERRIDE:
+ template: Parts must have exactly the same language version override as the library.
+ comment: |-
+ It is a compile-time error if a part file has a different language version
+ override than its library.
+
+ https://github.com/dart-lang/language/blob/master/accepted/
+ future-releases/language-versioning/feature-specification.md
+ #individual-library-language-version-override
+ INITIALIZER_FOR_NON_EXISTENT_FIELD:
+ template: "'{0}' isn't a field in the enclosing class."
+ tip: "Try correcting the name to match an existing field, or defining a field named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the initializing formal that is not an instance variable in
+ the immediately enclosing class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor initializes a
+ field that isn't declared in the class containing the constructor.
+ Constructors can't initialize fields that aren't declared and fields that
+ are inherited from superclasses.
+
+ #### Examples
+
+ The following code produces this diagnostic because the initializer is
+ initializing `x`, but `x` isn't a field in the class:
+
+ ```dart
+ %language=2.9
+ class C {
+ int y;
+
+ C() : [!x = 0!];
+ }
+ ```
+
+ #### Common fixes
+
+ If a different field should be initialized, then change the name to the
+ name of the field:
+
+ ```dart
+ %language=2.9
+ class C {
+ int y;
+
+ C() : y = 0;
+ }
+ ```
+
+ If the field must be declared, then add a declaration:
+
+ ```dart
+ %language=2.9
+ class C {
+ int x;
+ int y;
+
+ C() : x = 0;
+ }
+ ```
+ INITIALIZER_FOR_STATIC_FIELD:
+ template: "'{0}' is a static field in the enclosing class. Fields initialized in a constructor can't be static."
+ tip: Try removing the initialization.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the initializing formal that is a static variable in the
+ immediately enclosing class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a static field is initialized in
+ a constructor using either a field formal parameter or an assignment in the
+ initializer list.
+
+ #### Example
+
+ The following code produces this diagnostic because the static field `a` is
+ being initialized by the field formal parameter `this.a`:
+
+ ```dart
+ class C {
+ static int? a;
+ C([!this.a!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If the field should be an instance field, then remove the keyword `static`:
+
+ ```dart
+ class C {
+ int? a;
+ C(this.a);
+ }
+ ```
+
+ If you intended to initialize an instance field and typed the wrong name,
+ then correct the name of the field being initialized:
+
+ ```dart
+ class C {
+ static int? a;
+ int? b;
+ C(this.b);
+ }
+ ```
+
+ If you really want to initialize the static field, then move the
+ initialization into the constructor body:
+
+ ```dart
+ class C {
+ static int? a;
+ C(int? c) {
+ a = c;
+ }
+ }
+ ```
+ INITIALIZING_FORMAL_FOR_NON_EXISTENT_FIELD:
+ template: "'{0}' isn't a field in the enclosing class."
+ tip: "Try correcting the name to match an existing field, or defining a field named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the initializing formal that is not an instance variable in
+ the immediately enclosing class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a field formal parameter is
+ found in a constructor in a class that doesn't declare the field being
+ initialized. Constructors can't initialize fields that aren't declared and
+ fields that are inherited from superclasses.
+
+ #### Examples
+
+ The following code produces this diagnostic because the field `x` isn't
+ defined:
+
+ ```dart
+ %language=2.9
+ class C {
+ int y;
+
+ C([!this.x!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If the field name was wrong, then change it to the name of an existing
+ field:
+
+ ```dart
+ %language=2.9
+ class C {
+ int y;
+
+ C(this.y);
+ }
+ ```
+
+ If the field name is correct but hasn't yet been defined, then declare the
+ field:
+
+ ```dart
+ %language=2.9
+ class C {
+ int x;
+ int y;
+
+ C(this.x);
+ }
+ ```
+
+ If the parameter is needed but shouldn't initialize a field, then convert
+ it to a normal parameter and use it:
+
+ ```dart
+ %language=2.9
+ class C {
+ int y;
+
+ C(int x) : y = x * 2;
+ }
+ ```
+
+ If the parameter isn't needed, then remove it:
+
+ ```dart
+ %language=2.9
+ class C {
+ int y;
+
+ C();
+ }
+ ```
+ INSTANCE_ACCESS_TO_STATIC_MEMBER:
+ template: "Static {1} '{0}' can't be accessed through an instance."
+ tip: "Try using the class '{2}' to access the {1}."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the static member
+ 1: the kind of the static member (field, getter, setter, or method)
+ 2: the name of the defining class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an access operator is used to
+ access a static member through an instance of the class.
+
+ #### Examples
+
+ The following code produces this diagnostic because `zero` is a static
+ field, but it’s being accessed as if it were an instance field:
+
+ ```dart
+ void f(C c) {
+ c.[!zero!];
+ }
+
+ class C {
+ static int zero = 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Use the class to access the static member:
+
+ ```dart
+ void f(C c) {
+ C.zero;
+ }
+
+ class C {
+ static int zero = 0;
+ }
+ ```
+ INSTANCE_MEMBER_ACCESS_FROM_FACTORY:
+ template: "Instance members can't be accessed from a factory constructor."
+ tip: Try removing the reference to the instance member.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a factory constructor contains
+ an unqualified reference to an instance member. In a generative
+ constructor, the instance of the class is created and initialized before
+ the body of the constructor is executed, so the instance can be bound to
+ `this` and accessed just like it would be in an instance method. But, in a
+ factory constructor, the instance isn't created before executing the body,
+ so `this` can't be used to reference it.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` isn't in scope in
+ the factory constructor:
+
+ ```dart
+ class C {
+ int x;
+ factory C() {
+ return C._([!x!]);
+ }
+ C._(this.x);
+ }
+ ```
+
+ #### Common fixes
+
+ Rewrite the code so that it doesn't reference the instance member:
+
+ ```dart
+ class C {
+ int x;
+ factory C() {
+ return C._(0);
+ }
+ C._(this.x);
+ }
+ ```
+ INSTANCE_MEMBER_ACCESS_FROM_STATIC:
+ template: "Instance members can't be accessed from a static method."
+ tip: "Try removing the reference to the instance member, or removing the keyword 'static' from the method."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a static method contains an
+ unqualified reference to an instance member.
+
+ #### Examples
+
+ The following code produces this diagnostic because the instance field `x`
+ is being referenced in a static method:
+
+ ```dart
+ %language=2.9
+ class C {
+ int x;
+
+ static int m() {
+ return [!x!];
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the method must reference the instance member, then it can't be static,
+ so remove the keyword:
+
+ ```dart
+ %language=2.9
+ class C {
+ int x;
+
+ int m() {
+ return x;
+ }
+ }
+ ```
+
+ If the method can't be made an instance method, then add a parameter so
+ that an instance of the class can be passed in:
+
+ ```dart
+ %language=2.9
+ class C {
+ int x;
+
+ static int m(C c) {
+ return c.x;
+ }
+ }
+ ```
+ INSTANTIATE_ABSTRACT_CLASS:
+ template: "Abstract classes can't be instantiated."
+ tip: Try creating an instance of a concrete subtype.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds a constructor
+ invocation and the constructor is declared in an abstract class. Even
+ though you can't create an instance of an abstract class, abstract classes
+ can declare constructors that can be invoked by subclasses.
+
+ #### Examples
+
+ The following code produces this diagnostic because `C` is an abstract
+ class:
+
+ ```dart
+ abstract class C {}
+
+ var c = new [!C!]();
+ ```
+
+ #### Common fixes
+
+ If there's a concrete subclass of the abstract class that can be used, then
+ create an instance of the concrete subclass.
+ INSTANTIATE_ENUM:
+ template: "Enums can't be instantiated."
+ tip: Try using one of the defined constants.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an enum is instantiated. It's
+ invalid to create an instance of an enum by invoking a constructor; only
+ the instances named in the declaration of the enum can exist.
+
+ #### Example
+
+ The following code produces this diagnostic because the enum `E` is being
+ instantiated:
+
+ ```dart
+ enum E {a}
+
+ var e = [!E!]();
+ ```
+
+ #### Common fixes
+
+ If you intend to use an instance of the enum, then reference one of the
+ constants defined in the enum:
+
+ ```dart
+ enum E {a}
+
+ var e = E.a;
+ ```
+
+ If you intend to use an instance of a class, then use the name of that class in place of the name of the enum.
+ INSTANTIATE_TYPE_ALIAS_EXPANDS_TO_TYPE_PARAMETER:
+ template: "Type aliases that expand to a type parameter can't be instantiated."
+ tip: Try replacing it with a class.
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor invocation is
+ found where the type being instantiated is a type alias for one of the type
+ parameters of the type alias. This isn’t allowed because the value of the
+ type parameter is a type rather than a class.
+
+ #### Example
+
+ The following code produces this diagnostic because it creates an instance
+ of `A`, even though `A` is a type alias that is defined to be equivalent to
+ a type parameter:
+
+ ```dart
+ typedef A<T> = T;
+
+ void f() {
+ const [!A!]<int>();
+ }
+ ```
+
+ #### Common fixes
+
+ Use either a class name or a type alias defined to be a class, rather than
+ a type alias defined to be a type parameter:
+
+ ```dart
+ typedef A<T> = C<T>;
+
+ void f() {
+ const A<int>();
+ }
+
+ class C<T> {
+ const C();
+ }
+ ```
+ INTEGER_LITERAL_IMPRECISE_AS_DOUBLE:
+ template: "The integer literal is being used as a double, but can't be represented as a 64-bit double without overflow or loss of precision: '{0}'."
+ tip: "Try using the class 'BigInt', or switch to the closest valid double: '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the lexeme of the integer
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an integer literal is being
+ implicitly converted to a double, but can't be represented as a 64-bit
+ double without overflow or loss of precision. Integer literals are
+ implicitly converted to a double if the context requires the type `double`.
+
+ #### Example
+
+ The following code produces this diagnostic because the integer value
+ `9223372036854775807` can't be represented exactly as a double:
+
+ ```dart
+ double x = [!9223372036854775807!];
+ ```
+
+ #### Common fixes
+
+ If you need to use the exact value, then use the class `BigInt` to
+ represent the value:
+
+ ```dart
+ var x = BigInt.parse('9223372036854775807');
+ ```
+
+ If you need to use a double, then change the value to one that can be
+ represented exactly:
+
+ ```dart
+ double x = 9223372036854775808;
+ ```
+ INTEGER_LITERAL_OUT_OF_RANGE:
+ template: "The integer literal {0} can't be represented in 64 bits."
+ tip: "Try using the 'BigInt' class if you need an integer larger than 9,223,372,036,854,775,807 or less than -9,223,372,036,854,775,808."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an integer literal has a value
+ that is too large (positive) or too small (negative) to be represented in a
+ 64-bit word.
+
+ #### Example
+
+ The following code produces this diagnostic because the value can't be
+ represented in 64 bits:
+
+ ```dart
+ var x = [!9223372036854775810!];
+ ```
+
+ #### Common fixes
+
+ If you need to represent the current value, then wrap it in an instance of
+ the class `BigInt`:
+
+ ```dart
+ var x = BigInt.parse('9223372036854775810');
+ ```
+ INVALID_ANNOTATION:
+ template: Annotation must be either a const variable reference or const constructor invocation.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an annotation is found that is
+ using something that is neither a variable marked as `const` or the
+ invocation of a `const` constructor.
+
+ Getters can't be used as annotations.
+
+ #### Example
+
+ The following code produces this diagnostic because the variable `v` isn't
+ a `const` variable:
+
+ ```dart
+ var v = 0;
+
+ [!@v!]
+ void f() {
+ }
+ ```
+
+ The following code produces this diagnostic because `f` isn't a variable:
+
+ ```dart
+ [!@f!]
+ void f() {
+ }
+ ```
+
+ The following code produces this diagnostic because `f` isn't a
+ constructor:
+
+ ```dart
+ [!@f()!]
+ void f() {
+ }
+ ```
+
+ The following code produces this diagnostic because `g` is a getter:
+
+ ```dart
+ [!@g!]
+ int get g => 0;
+ ```
+
+ #### Common fixes
+
+ If the annotation is referencing a variable that isn't a `const`
+ constructor, add the keyword `const` to the variable's declaration:
+
+ ```dart
+ const v = 0;
+
+ @v
+ void f() {
+ }
+ ```
+
+ If the annotation isn't referencing a variable, then remove it:
+
+ ```dart
+ int v = 0;
+
+ void f() {
+ }
+ ```
+ INVALID_ANNOTATION_CONSTANT_VALUE_FROM_DEFERRED_LIBRARY:
+ template: "Constant values from a deferred library can't be used in annotations."
+ tip: "Try moving the constant from the deferred library, or removing 'deferred' from the import."
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constant defined in a library
+ that is imported as a deferred library is referenced in the argument list
+ of an annotation. Annotations are evaluated at compile time, and values
+ from deferred libraries aren't available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ The following code produces this diagnostic because the constant `pi` is
+ being referenced in the argument list of an annotation, even though the
+ library that defines it is being imported as a deferred library:
+
+ ```dart
+ import 'dart:math' deferred as math;
+
+ class C {
+ const C(double d);
+ }
+
+ @C([!math.pi!])
+ void f () {}
+ ```
+
+ #### Common fixes
+
+ If you need to reference the imported constant, then remove the `deferred`
+ keyword:
+
+ ```dart
+ import 'dart:math' as math;
+
+ class C {
+ const C(double d);
+ }
+
+ @C(math.pi)
+ void f () {}
+ ```
+
+ If the import is required to be deferred and there's another constant that
+ is appropriate, then use that constant in place of the constant from the
+ deferred library.
+ INVALID_ANNOTATION_FROM_DEFERRED_LIBRARY:
+ template: "Constant values from a deferred library can't be used as annotations."
+ tip: Try removing the annotation, or changing the import to not be deferred.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constant from a library that
+ is imported using a deferred import is used as an annotation. Annotations
+ are evaluated at compile time, and constants from deferred libraries aren't
+ available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ The following code produces this diagnostic because the constant `pi` is
+ being used as an annotation when the library `dart:math` is imported as
+ `deferred`:
+
+ ```dart
+ import 'dart:math' deferred as math;
+
+ @[!math.pi!]
+ void f() {}
+ ```
+
+ #### Common fixes
+
+ If you need to reference the constant as an annotation, then remove the
+ keyword `deferred` from the import:
+
+ ```dart
+ import 'dart:math' as math;
+
+ @math.pi
+ void f() {}
+ ```
+
+ If you can use a different constant as an annotation, then replace the
+ annotation with a different constant:
+
+ ```dart
+ @deprecated
+ void f() {}
+ ```
+ INVALID_ASSIGNMENT:
+ template: "A value of type '{0}' can't be assigned to a variable of type '{1}'."
+ tip: "Try changing the type of the variable, or casting the right-hand type to '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the right hand side type
+ 1: the name of the left hand side type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the static type of an expression
+ that is assigned to a variable isn't assignable to the type of the
+ variable.
+
+ #### Examples
+
+ The following code produces this diagnostic because the type of the
+ initializer (`int`) isn't assignable to the type of the variable
+ (`String`):
+
+ ```dart
+ int i = 0;
+ String s = [!i!];
+ ```
+
+ #### Common fixes
+
+ If the value being assigned is always assignable at runtime, even though
+ the static types don't reflect that, then add an explicit cast.
+
+ Otherwise, change the value being assigned so that it has the expected
+ type. In the previous example, this might look like:
+
+ ```dart
+ int i = 0;
+ String s = i.toString();
+ ```
+
+ If you can’t change the value, then change the type of the variable to be
+ compatible with the type of the value being assigned:
+
+ ```dart
+ int i = 0;
+ int s = i;
+ ```
+ INVALID_CAST_FUNCTION:
+ template: "The function '{0}' has type '{1}' that isn't of expected type '{2}'. This means its parameter or return type doesn't match what is expected."
+ comment: |-
+ Parameters:
+ 0: the type of the function
+ 1: the expected function type
+ INVALID_CAST_FUNCTION_EXPR:
+ template: "The function expression type '{0}' isn't of type '{1}'. This means its parameter or return type doesn't match what is expected. Consider changing parameter type(s) or the returned type(s)."
+ comment: |-
+ Parameters:
+ 0: the type of the torn-off function expression
+ 1: the expected function type
+ INVALID_CAST_LITERAL:
+ template: "The literal '{0}' with type '{1}' isn't of expected type '{2}'."
+ comment: |-
+ Parameters:
+ 0: the type of the literal
+ 1: the expected type
+ INVALID_CAST_LITERAL_LIST:
+ template: "The list literal type '{0}' isn't of expected type '{1}'. The list's type can be changed with an explicit generic type argument or by changing the element types."
+ comment: |-
+ Parameters:
+ 0: the type of the list literal
+ 1: the expected type
+ INVALID_CAST_LITERAL_MAP:
+ template: "The map literal type '{0}' isn't of expected type '{1}'. The maps's type can be changed with an explicit generic type arguments or by changing the key and value types."
+ comment: |-
+ Parameters:
+ 0: the type of the map literal
+ 1: the expected type
+ INVALID_CAST_LITERAL_SET:
+ template: "The set literal type '{0}' isn't of expected type '{1}'. The set's type can be changed with an explicit generic type argument or by changing the element types."
+ comment: |-
+ Parameters:
+ 0: the type of the set literal
+ 1: the expected type
+ INVALID_CAST_METHOD:
+ template: "The method tear-off '{0}' has type '{1}' that isn't of expected type '{2}'. This means its parameter or return type doesn't match what is expected."
+ comment: |-
+ Parameters:
+ 0: the type of the torn-off method
+ 1: the expected function type
+ INVALID_CAST_NEW_EXPR:
+ template: "The constructor returns type '{0}' that isn't of expected type '{1}'."
+ comment: |-
+ Parameters:
+ 0: the type of the instantiated object
+ 1: the expected type
+ INVALID_CONSTANT:
+ template: Invalid constant value.
+ comment: |-
+ TODO(brianwilkerson) Remove this when we have decided on how to report
+ errors in compile-time constants. Until then, this acts as a placeholder
+ for more informative errors.
+
+ See TODOs in ConstantVisitor
+ INVALID_CONSTRUCTOR_NAME:
+ template: Invalid constructor name.
+ comment: |-
+ 7.6 Constructors: It is a compile-time error if the name of a constructor
+ is not a constructor name.
+ INVALID_EXTENSION_ARGUMENT_COUNT:
+ template: "Extension overrides must have exactly one argument: the value of 'this' in the extension method."
+ tip: Try specifying exactly one argument.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override doesn't
+ have exactly one argument. The argument is the expression used to compute
+ the value of `this` within the extension method, so there must be one
+ argument.
+
+ #### Examples
+
+ The following code produces this diagnostic because there are no arguments:
+
+ ```dart
+ extension E on String {
+ String join(String other) => '$this $other';
+ }
+
+ void f() {
+ E[!()!].join('b');
+ }
+ ```
+
+ And, the following code produces this diagnostic because there's more than
+ one argument:
+
+ ```dart
+ extension E on String {
+ String join(String other) => '$this $other';
+ }
+
+ void f() {
+ E[!('a', 'b')!].join('c');
+ }
+ ```
+
+ #### Common fixes
+
+ Provide one argument for the extension override:
+
+ ```dart
+ extension E on String {
+ String join(String other) => '$this $other';
+ }
+
+ void f() {
+ E('a').join('b');
+ }
+ ```
+ INVALID_FACTORY_NAME_NOT_A_CLASS:
+ template: The name of a factory constructor must be the same as the name of the immediately enclosing class.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name of a factory
+ constructor isn't the same as the name of the surrounding class.
+
+ #### Examples
+
+ The following code produces this diagnostic because the name of the factory
+ constructor (`A`) isn't the same as the surrounding class (`C`):
+
+ ```dart
+ class A {}
+
+ class C {
+ factory [!A!]() => throw 0;
+ }
+ ```
+
+ #### Common fixes
+
+ If the factory returns an instance of the surrounding class, then rename
+ the factory:
+
+ ```dart
+ class A {}
+
+ class C {
+ factory C() => throw 0;
+ }
+ ```
+
+ If the factory returns an instance of a different class, then move the
+ factory to that class:
+
+ ```dart
+ class A {
+ factory A() => throw 0;
+ }
+
+ class C {}
+ ```
+
+ If the factory returns an instance of a different class, but you can't
+ modify that class or don't want to move the factory, then convert it to be
+ a static method:
+
+ ```dart
+ class A {}
+
+ class C {
+ static A a() => throw 0;
+ }
+ ```
+ INVALID_IMPLEMENTATION_OVERRIDE:
+ template: "'{1}.{0}' ('{2}') isn't a valid concrete implementation of '{3}.{0}' ('{4}')."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the declared member that is not a valid override.
+ 1: the name of the interface that declares the member.
+ 2: the type of the declared member in the interface.
+ 3. the name of the interface with the overridden member.
+ 4. the type of the overridden member.
+
+ These parameters must be kept in sync with those of
+ [CompileTimeErrorCode.INVALID_OVERRIDE].
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when all of the following are true:
+
+ - A class defines an abstract member.
+ - There is a concrete implementation of that member in a superclass.
+ - The concrete implementation isn't a valid implementation of the abstract
+ method.
+
+ The concrete implementation can be invalid because of incompatibilities in
+ either the return type, the types of parameters, or the type variables.
+
+ #### Example
+
+ The following code produces this diagnostic because the method `A.add` has
+ a parameter of type `int`, and the overriding method `B.add` has a
+ corresponding parameter of type `num`:
+
+ ```dart
+ class A {
+ int add(int a) => a;
+ }
+ class [!B!] extends A {
+ int add(num a);
+ }
+ ```
+
+ This is a problem because in an invocation of `B.add` like the following:
+
+ ```dart
+ void f(B b) {
+ b.add(3.4);
+ }
+ ```
+
+ `B.add` is expecting to be able to take, for example, a `double`, but when
+ the method `A.add` is executed (because it's the only concrete
+ implementation of `add`), a runtime exception will be thrown because a
+ `double` can't be assigned to a parameter of type `int`.
+
+ #### Common fixes
+
+ If the method in the subclass can conform to the implementation in the
+ superclass, then change the declaration in the subclass (or remove it if
+ it's the same):
+
+ ```dart
+ class A {
+ int add(int a) => a;
+ }
+ class B extends A {
+ int add(int a);
+ }
+ ```
+
+ If the method in the superclass can be generalized to be a valid
+ implementation of the method in the subclass, then change the superclass
+ method:
+
+ ```dart
+ class A {
+ int add(num a) => a.floor();
+ }
+ class B extends A {
+ int add(num a);
+ }
+ ```
+
+ If neither the method in the superclass nor the method in the subclass can
+ be changed, then provide a concrete implementation of the method in the
+ subclass:
+
+ ```dart
+ class A {
+ int add(int a) => a;
+ }
+ class B extends A {
+ int add(num a) => a.floor();
+ }
+ ```
+ INVALID_INLINE_FUNCTION_TYPE:
+ template: "Inline function types can't be used for parameters in a generic function type."
+ tip: "Try using a generic function type (returnType 'Function(' parameters ')')."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a generic function type has a
+ function-valued parameter that is written using the older inline function
+ type syntax.
+
+ #### Example
+
+ The following code produces this diagnostic because the parameter `f`, in
+ the generic function type used to define `F`, uses the inline function
+ type syntax:
+
+ ```dart
+ typedef F = int Function(int f[!(!]String s));
+ ```
+
+ #### Common fixes
+
+ Use the generic function syntax for the parameter's type:
+
+ ```dart
+ typedef F = int Function(int Function(String));
+ ```
+ INVALID_MODIFIER_ON_CONSTRUCTOR:
+ template: "The modifier '{0}' can't be applied to the body of a constructor."
+ tip: Try removing the modifier.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the invalid modifier
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the body of a constructor is
+ prefixed by one of the following modifiers: `async`, `async*`, or `sync*`.
+ Constructor bodies must be synchronous.
+
+ #### Example
+
+ The following code produces this diagnostic because the body of the
+ constructor for `C` is marked as being `async`:
+
+ ```dart
+ class C {
+ C() [!async!] {}
+ }
+ ```
+
+ #### Common fixes
+
+ If the constructor can be synchronous, then remove the modifier:
+
+ ```dart
+ class C {
+ C();
+ }
+ ```
+
+ If the constructor can't be synchronous, then use a static method to create
+ the instance instead:
+
+ ```dart
+ class C {
+ C();
+ static Future<C> c() async {
+ return C();
+ }
+ }
+ ```
+ INVALID_MODIFIER_ON_SETTER:
+ template: "Setters can't use 'async', 'async*', or 'sync*'."
+ tip: Try removing the modifier.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the invalid modifier
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the body of a setter is prefixed
+ by one of the following modifiers: `async`, `async*`, or `sync*`. Setter
+ bodies must be synchronous.
+
+ #### Example
+
+ The following code produces this diagnostic because the body of the setter
+ `x` is marked as being `async`:
+
+ ```dart
+ class C {
+ set x(int i) [!async!] {}
+ }
+ ```
+
+ #### Common fixes
+
+ If the setter can be synchronous, then remove the modifier:
+
+ ```dart
+ class C {
+ set x(int i) {}
+ }
+ ```
+
+ If the setter can't be synchronous, then use a method to set the value
+ instead:
+
+ ```dart
+ class C {
+ void x(int i) async {}
+ }
+ ```
+ INVALID_OVERRIDE:
+ template: "'{1}.{0}' ('{2}') isn't a valid override of '{3}.{0}' ('{4}')."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the declared member that is not a valid override.
+ 1: the name of the interface that declares the member.
+ 2: the type of the declared member in the interface.
+ 3. the name of the interface with the overridden member.
+ 4. the type of the overridden member.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a member of a class is found
+ that overrides a member from a supertype and the override isn't valid. An
+ override is valid if all of these are true:
+ * It allows all of the arguments allowed by the overridden member.
+ * It doesn't require any arguments that aren't required by the overridden
+ member.
+ * The type of every parameter of the overridden member is assignable to the
+ corresponding parameter of the override.
+ * The return type of the override is assignable to the return type of the
+ overridden member.
+
+ #### Examples
+
+ The following code produces this diagnostic because the type of the
+ parameter `s` (`String`) isn't assignable to the type of the parameter `i`
+ (`int`):
+
+ ```dart
+ class A {
+ void m(int i) {}
+ }
+
+ class B extends A {
+ void [!m!](String s) {}
+ }
+ ```
+
+ #### Common fixes
+
+ If the invalid method is intended to override the method from the
+ superclass, then change it to conform:
+
+ ```dart
+ class A {
+ void m(int i) {}
+ }
+
+ class B extends A {
+ void m(int i) {}
+ }
+ ```
+
+ If it isn't intended to override the method from the superclass, then
+ rename it:
+
+ ```dart
+ class A {
+ void m(int i) {}
+ }
+
+ class B extends A {
+ void m2(String s) {}
+ }
+ ```
+ INVALID_REFERENCE_TO_THIS:
+ template: "Invalid reference to 'this' expression."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when `this` is used outside of an
+ instance method or a generative constructor. The reserved word `this` is
+ only defined in the context of an instance method or a generative
+ constructor.
+
+ #### Examples
+
+ The following code produces this diagnostic because `v` is a top-level
+ variable:
+
+ ```dart
+ C f() => [!this!];
+
+ class C {}
+ ```
+
+ #### Common fixes
+
+ Use a variable of the appropriate type in place of `this`, declaring it if
+ necessary:
+
+ ```dart
+ C f(C c) => c;
+
+ class C {}
+ ```
+ INVALID_SUPER_INVOCATION:
+ template: "The superclass call must be last in an initializer list: '{0}'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the initializer list of a
+ constructor contains an invocation of a constructor in the superclass, but
+ the invocation isn't the last item in the initializer list.
+
+ #### Example
+
+ The following code produces this diagnostic because the invocation of the
+ superclass' constructor isn't the last item in the initializer list:
+
+ ```dart
+ class A {
+ A(int x);
+ }
+
+ class B extends A {
+ B(int x) : [!super!](x), assert(x >= 0);
+ }
+ ```
+
+ #### Common fixes
+
+ Move the invocation of the superclass' constructor to the end of the
+ initializer list:
+
+ ```dart
+ class A {
+ A(int x);
+ }
+
+ class B extends A {
+ B(int x) : assert(x >= 0), super(x);
+ }
+ ```
+ INVALID_TYPE_ARGUMENT_IN_CONST_LIST:
+ sharedName: INVALID_TYPE_ARGUMENT_IN_CONST_LITERAL
+ template: "Constant list literals can't include a type parameter as a type argument, such as '{0}'."
+ tip: Try replacing the type parameter with a different type.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type parameter
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a type parameter is used as a
+ type argument in a list, map, or set literal that is prefixed by `const`.
+ This isn't allowed because the value of the type parameter (the actual type
+ that will be used at runtime) can't be known at compile time.
+
+ #### Example
+
+ The following code produces this diagnostic because the type parameter `T`
+ is being used as a type argument when creating a constant list:
+
+ ```dart
+ List<T> newList<T>() => const <[!T!]>[];
+ ```
+
+ The following code produces this diagnostic because the type parameter `T`
+ is being used as a type argument when creating a constant map:
+
+ ```dart
+ Map<String, T> newSet<T>() => const <String, [!T!]>{};
+ ```
+
+ The following code produces this diagnostic because the type parameter `T`
+ is being used as a type argument when creating a constant set:
+
+ ```dart
+ Set<T> newSet<T>() => const <[!T!]>{};
+ ```
+
+ #### Common fixes
+
+ If the type that will be used for the type parameter can be known at
+ compile time, then remove the type parameter:
+
+ ```dart
+ List<int> newList() => const <int>[];
+ ```
+
+ If the type that will be used for the type parameter can't be known until
+ runtime, then remove the keyword `const`:
+
+ ```dart
+ List<T> newList<T>() => <T>[];
+ ```
+ INVALID_TYPE_ARGUMENT_IN_CONST_MAP:
+ sharedName: INVALID_TYPE_ARGUMENT_IN_CONST_LITERAL
+ template: "Constant map literals can't include a type parameter as a type argument, such as '{0}'."
+ tip: Try replacing the type parameter with a different type.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type parameter
+ INVALID_TYPE_ARGUMENT_IN_CONST_SET:
+ sharedName: INVALID_TYPE_ARGUMENT_IN_CONST_LITERAL
+ template: "Constant set literals can't include a type parameter as a type argument, such as '{0}'."
+ tip: Try replacing the type parameter with a different type.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type parameter
+ INVALID_URI:
+ template: "Invalid URI syntax: '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the URI that is invalid
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a URI in a directive doesn't
+ conform to the syntax of a valid URI.
+
+ #### Examples
+
+ The following code produces this diagnostic because `'#'` isn't a valid
+ URI:
+
+ ```dart
+ import [!'#'!];
+ ```
+
+ #### Common fixes
+
+ Replace the invalid URI with a valid URI.
+ INVALID_USE_OF_COVARIANT:
+ template: "The 'covariant' keyword can only be used for parameters in instance methods or before non-final instance fields."
+ tip: "Try removing the 'covariant' keyword."
+ comment: "The 'covariant' keyword was found in an inappropriate location."
+ INVALID_USE_OF_NULL_VALUE:
+ template: "An expression whose value is always 'null' can't be dereferenced."
+ tip: Try changing the type of the expression.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an expression whose value will
+ always be `null` is dereferenced.
+
+ #### Example
+
+ The following code produces this diagnostic because `x` will always be
+ `null`:
+
+ ```dart
+ int f(Null x) {
+ return [!x!].length;
+ }
+ ```
+
+ #### Common fixes
+
+ If the value is allowed to be something other than `null`, then change the
+ type of the expression:
+
+ ```dart
+ int f(String? x) {
+ return x!.length;
+ }
+ ```
+ INVOCATION_OF_EXTENSION_WITHOUT_CALL:
+ template: "The extension '{0}' doesn't define a 'call' method so the override can't be used in an invocation."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the extension
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override is used to
+ invoke a function but the extension doesn't declare a `call` method.
+
+ #### Examples
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't define a `call` method:
+
+ ```dart
+ extension E on String {}
+
+ void f() {
+ [!E('')!]();
+ }
+ ```
+
+ #### Common fixes
+
+ If the extension is intended to define a `call` method, then declare it:
+
+ ```dart
+ extension E on String {
+ int call() => 0;
+ }
+
+ void f() {
+ E('')();
+ }
+ ```
+
+ If the extended type defines a `call` method, then remove the extension
+ override.
+
+ If the `call` method isn't defined, then rewrite the code so that it
+ doesn't invoke the `call` method.
+ INVOCATION_OF_NON_FUNCTION:
+ template: "'{0}' isn't a function."
+ tip: "Try correcting the name to match an existing function, or define a method or function named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the identifier that is not a function type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds a function invocation,
+ but the name of the function being invoked is defined to be something other
+ than a function.
+
+ #### Examples
+
+ The following code produces this diagnostic because `Binary` is the name of
+ a function type, not a function:
+
+ ```dart
+ typedef Binary = int Function(int, int);
+
+ int f() {
+ return [!Binary!](1, 2);
+ }
+ ```
+
+ #### Common fixes
+
+ Replace the name with the name of a function.
+ INVOCATION_OF_NON_FUNCTION_EXPRESSION:
+ template: "The expression doesn't evaluate to a function, so it can't be invoked."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a function invocation is found,
+ but the name being referenced isn't the name of a function, or when the
+ expression computing the function doesn't compute a function.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` isn't a function:
+
+ ```dart
+ int x = 0;
+
+ int f() => x;
+
+ var y = [!x!]();
+ ```
+
+ The following code produces this diagnostic because `f()` doesn't return a
+ function:
+
+ ```dart
+ int x = 0;
+
+ int f() => x;
+
+ var y = [!f()!]();
+ ```
+
+ #### Common fixes
+
+ If you need to invoke a function, then replace the code before the argument
+ list with the name of a function or with an expression that computes a
+ function:
+
+ ```dart
+ int x = 0;
+
+ int f() => x;
+
+ var y = f();
+ ```
+ LABEL_IN_OUTER_SCOPE:
+ template: "Can't reference label '{0}' declared in an outer method."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the unresolvable label
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `break` or `continue`
+ statement references a label that is declared in a method or function
+ containing the function in which the `break` or `continue` statement
+ appears. The `break` and `continue` statements can't be used to transfer
+ control outside the function that contains them.
+
+ #### Example
+
+ The following code produces this diagnostic because the label `loop` is
+ declared outside the local function `g`:
+
+ ```dart
+ void f() {
+ loop:
+ while (true) {
+ void g() {
+ break [!loop!];
+ }
+
+ g();
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Try rewriting the code so that it isn't necessary to transfer control
+ outside the local function, possibly by inlining the local function:
+
+ ```dart
+ void f() {
+ loop:
+ while (true) {
+ break loop;
+ }
+ }
+ ```
+
+ If that isn't possible, then try rewriting the local function so that a
+ value returned by the function can be used to determine whether control is
+ transferred:
+
+ ```dart
+ void f() {
+ loop:
+ while (true) {
+ bool g() {
+ return true;
+ }
+
+ if (g()) {
+ break loop;
+ }
+ }
+ }
+ ```
+ LABEL_UNDEFINED:
+ template: "Can't reference an undefined label '{0}'."
+ tip: Try defining the label, or correcting the name to match an existing label.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the unresolvable label
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds a reference to a label
+ that isn't defined in the scope of the `break` or `continue` statement that
+ is referencing it.
+
+ #### Example
+
+ The following code produces this diagnostic because the label `loop` isn't
+ defined anywhere:
+
+ ```dart
+ void f() {
+ for (int i = 0; i < 10; i++) {
+ for (int j = 0; j < 10; j++) {
+ break [!loop!];
+ }
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the label should be on the innermost enclosing `do`, `for`, `switch`, or
+ `while` statement, then remove the label:
+
+ ```dart
+ void f() {
+ for (int i = 0; i < 10; i++) {
+ for (int j = 0; j < 10; j++) {
+ break;
+ }
+ }
+ }
+ ```
+
+ If the label should be on some other statement, then add the label:
+
+ ```dart
+ void f() {
+ loop: for (int i = 0; i < 10; i++) {
+ for (int j = 0; j < 10; j++) {
+ break loop;
+ }
+ }
+ }
+ ```
+ LATE_FINAL_FIELD_WITH_CONST_CONSTRUCTOR:
+ template: "Can't have a late final field in a class with a generative const constructor."
+ tip: "Try removing the 'late' modifier, or don't declare 'const' constructors."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class that has at least one
+ `const` constructor also has a field marked both `late` and `final`.
+
+ #### Example
+
+ The following code produces this diagnostic because the class `A` has a
+ `const` constructor and the `final` field `f` is marked as `late`:
+
+ ```dart
+ class A {
+ [!late!] final int f;
+
+ const A();
+ }
+ ```
+
+ #### Common fixes
+
+ If the field doesn't need to be marked `late`, then remove the `late`
+ modifier from the field:
+
+ ```dart
+ class A {
+ final int f = 0;
+
+ const A();
+ }
+ ```
+
+ If the field must be marked `late`, then remove the `const` modifier from
+ the constructors:
+
+ ```dart
+ class A {
+ late final int f;
+
+ A();
+ }
+ ```
+ LATE_FINAL_LOCAL_ALREADY_ASSIGNED:
+ template: The late final local variable is already assigned.
+ tip: "Try removing the 'final' modifier, or don't reassign the value."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the analyzer can prove that a
+ local variable marked as both `late` and `final` was already assigned a
+ value at the point where another assignment occurs.
+
+ Because `final` variables can only be assigned once, subsequent assignments
+ are guaranteed to fail, so they're flagged.
+
+ #### Example
+
+ The following code produces this diagnostic because the `final` variable
+ `v` is assigned a value in two places:
+
+ ```dart
+ int f() {
+ late final int v;
+ v = 0;
+ [!v!] += 1;
+ return v;
+ }
+ ```
+
+ #### Common fixes
+
+ If you need to be able to reassign the variable, then remove the `final`
+ keyword:
+
+ ```dart
+ int f() {
+ late int v;
+ v = 0;
+ v += 1;
+ return v;
+ }
+ ```
+
+ If you don't need to reassign the variable, then remove all except the
+ first of the assignments:
+
+ ```dart
+ int f() {
+ late final int v;
+ v = 0;
+ return v;
+ }
+ ```
+ LIST_ELEMENT_TYPE_NOT_ASSIGNABLE:
+ template: "The element type '{0}' can't be assigned to the list type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the actual type of the list element
+ 1: the expected type of the list element
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type of an element in a list
+ literal isn't assignable to the element type of the list.
+
+ #### Examples
+
+ The following code produces this diagnostic because `2.5` is a double, and
+ the list can hold only integers:
+
+ ```dart
+ List<int> x = [1, [!2.5!], 3];
+ ```
+
+ #### Common fixes
+
+ If you intended to add a different object to the list, then replace the
+ element with an expression that computes the intended object:
+
+ ```dart
+ List<int> x = [1, 2, 3];
+ ```
+
+ If the object shouldn't be in the list, then remove the element:
+
+ ```dart
+ List<int> x = [1, 3];
+ ```
+
+ If the object being computed is correct, then widen the element type of the
+ list to allow all of the different types of objects it needs to contain:
+
+ ```dart
+ List<num> x = [1, 2.5, 3];
+ ```
+ MAIN_FIRST_POSITIONAL_PARAMETER_TYPE:
+ template: "The type of the first positional parameter of the 'main' function must be a supertype of 'List<String>'."
+ tip: Try changing the type of the parameter.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the first positional parameter
+ of a function named `main` isn't a supertype of `List<String>`.
+
+ #### Example
+
+ The following code produces this diagnostic because `List<int>` isn't a
+ supertype of `List<String>`:
+
+ ```dart
+ void main([!List<int>!] args) {}
+ ```
+
+ #### Common fixes
+
+ If the function is an entry point, then change the type of the first
+ positional parameter to be a supertype of `List<String>`:
+
+ ```dart
+ void main(List<String> args) {}
+ ```
+
+ If the function isn't an entry point, then change the name of the function:
+
+ ```dart
+ void f(List<int> args) {}
+ ```
+ MAIN_HAS_REQUIRED_NAMED_PARAMETERS:
+ template: "The function 'main' can't have any required named parameters."
+ tip: "Try using a different name for the function, or removing the 'required' modifier."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a function named `main` has one
+ or more required named parameters.
+
+ #### Example
+
+ The following code produces this diagnostic because the function named
+ `main` has a required named parameter (`x`):
+
+ ```dart
+ void [!main!]({required int x}) {}
+ ```
+
+ #### Common fixes
+
+ If the function is an entry point, then remove the `required` keyword:
+
+ ```dart
+ void main({int? x}) {}
+ ```
+
+ If the function isn't an entry point, then change the name of the function:
+
+ ```dart
+ void f({required int x}) {}
+ ```
+ MAIN_HAS_TOO_MANY_REQUIRED_POSITIONAL_PARAMETERS:
+ template: "The function 'main' can't have more than two required positional parameters."
+ tip: Try using a different name for the function, or removing extra parameters.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a function named `main` has more
+ than two required positional parameters.
+
+ #### Example
+
+ The following code produces this diagnostic because the function `main` has
+ three required positional parameters:
+
+ ```dart
+ void [!main!](List<String> args, int x, int y) {}
+ ```
+
+ #### Common fixes
+
+ If the function is an entry point and the extra parameters aren't used,
+ then remove them:
+
+ ```dart
+ void main(List<String> args, int x) {}
+ ```
+
+ If the function is an entry point, but the extra parameters used are for
+ when the function isn't being used as an entry point, then make the extra
+ parameters optional:
+
+ ```dart
+ void main(List<String> args, int x, [int y = 0]) {}
+ ```
+
+ If the function isn't an entry point, then change the name of the function:
+
+ ```dart
+ void f(List<String> args, int x, int y) {}
+ ```
+ MAIN_IS_NOT_FUNCTION:
+ template: "The declaration named 'main' must be a function."
+ tip: Try using a different name for this declaration.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a library contains a declaration
+ of the name `main` that isn't the declaration of a top-level function.
+
+ #### Example
+
+ The following code produces this diagnostic because the name `main` is
+ being used to declare a top-level variable:
+
+ ```dart
+ var [!main!] = 3;
+ ```
+
+ #### Common fixes
+
+ Use a different name for the declaration:
+
+ ```dart
+ var mainIndex = 3;
+ ```
+ MAP_ENTRY_NOT_IN_MAP:
+ template: Map entries can only be used in a map literal.
+ tip: Try converting the collection to a map or removing the map entry.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a map entry (a key/value pair)
+ is found in a set literal.
+
+ #### Examples
+
+ The following code produces this diagnostic because the literal has a map
+ entry even though it's a set literal:
+
+ ```dart
+ const collection = <String>{[!'a' : 'b'!]};
+ ```
+
+ #### Common fixes
+
+ If you intended for the collection to be a map, then change the code so
+ that it is a map. In the previous example, you could do this by adding
+ another type argument:
+
+ ```dart
+ const collection = <String, String>{'a' : 'b'};
+ ```
+
+ In other cases, you might need to change the explicit type from `Set` to
+ `Map`.
+
+ If you intended for the collection to be a set, then remove the map entry,
+ possibly by replacing the colon with a comma if both values should be
+ included in the set:
+
+ ```dart
+ const collection = <String>{'a', 'b'};
+ ```
+ MAP_KEY_TYPE_NOT_ASSIGNABLE:
+ template: "The element type '{0}' can't be assigned to the map key type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the expression being used as a key
+ 1: the type of keys declared for the map
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a key of a key-value pair in a
+ map literal has a type that isn't assignable to the key type of the map.
+
+ #### Examples
+
+ The following code produces this diagnostic because `2` is an `int`, but
+ the keys of the map are required to be `String`s:
+
+ ```dart
+ var m = <String, String>{[!2!] : 'a'};
+ ```
+
+ #### Common fixes
+
+ If the type of the map is correct, then change the key to have the correct
+ type:
+
+ ```dart
+ var m = <String, String>{'2' : 'a'};
+ ```
+
+ If the type of the key is correct, then change the key type of the map:
+
+ ```dart
+ var m = <int, String>{2 : 'a'};
+ ```
+ MAP_VALUE_TYPE_NOT_ASSIGNABLE:
+ template: "The element type '{0}' can't be assigned to the map value type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the expression being used as a value
+ 1: the type of values declared for the map
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a value of a key-value pair in a
+ map literal has a type that isn't assignable to the the value type of the
+ map.
+
+ #### Examples
+
+ The following code produces this diagnostic because `2` is an `int`, but/
+ the values of the map are required to be `String`s:
+
+ ```dart
+ var m = <String, String>{'a' : [!2!]};
+ ```
+
+ #### Common fixes
+
+ If the type of the map is correct, then change the value to have the
+ correct type:
+
+ ```dart
+ var m = <String, String>{'a' : '2'};
+ ```
+
+ If the type of the value is correct, then change the value type of the map:
+
+ ```dart
+ var m = <String, int>{'a' : 2};
+ ```
+ MISSING_CONST_IN_LIST_LITERAL:
+ template: "List literals must be prefixed with 'const' when used as a constant expression."
+ tip: "Try adding the keyword 'const' before the literal."
+ comment: "12.1 Constants: A constant expression is ... a constant list literal."
+ MISSING_CONST_IN_MAP_LITERAL:
+ template: "Map literals must be prefixed with 'const' when used as a constant expression."
+ tip: "Try adding the keyword 'const' before the literal."
+ comment: "12.1 Constants: A constant expression is ... a constant map literal."
+ MISSING_CONST_IN_SET_LITERAL:
+ template: "Set literals must be prefixed with 'const' when used as a constant expression."
+ tip: "Try adding the keyword 'const' before the literal."
+ comment: "12.1 Constants: A constant expression is ... a constant set literal."
+ MISSING_DART_LIBRARY:
+ template: "Required library '{0}' is missing."
+ tip: Re-install the Dart or Flutter SDK.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when either the Dart or Flutter SDK
+ isn’t installed correctly, and, as a result, one of the `dart:` libraries
+ can't be found.
+
+ #### Common fixes
+
+ Reinstall the Dart or Flutter SDK.
+ MISSING_DEFAULT_VALUE_FOR_PARAMETER:
+ template: "The parameter '{0}' can't have a value of 'null' because of its type, but the implicit default value is 'null'."
+ tip: "Try adding either an explicit non-'null' default value or the 'required' modifier."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an optional parameter, whether
+ positional or named, has a [potentially non-nullable][] type and doesn't
+ specify a default value. Optional parameters that have no explicit default
+ value have an implicit default value of `null`. If the type of the
+ parameter doesn't allow the parameter to have a value of `null`, then the
+ implicit default value isn't valid.
+
+ #### Example
+
+ The following code produces this diagnostic because `x` can't be `null`,
+ and no non-`null` default value is specified:
+
+ ```dart
+ void f([int [!x!]]) {}
+ ```
+
+ As does this:
+
+ ```dart
+ void g({int [!x!]}) {}
+ ```
+
+ #### Common fixes
+
+ If you want to use `null` to indicate that no value was provided, then you
+ need to make the type nullable:
+
+ ```dart
+ void f([int? x]) {}
+ void g({int? x}) {}
+ ```
+
+ If the parameter can't be null, then either provide a default value:
+
+ ```dart
+ void f([int x = 1]) {}
+ void g({int x = 2}) {}
+ ```
+
+ or make the parameter a required parameter:
+
+ ```dart
+ void f(int x) {}
+ void g({required int x}) {}
+ ```
+ MISSING_REQUIRED_ARGUMENT:
+ template: "The named parameter '{0}' is required, but there's no corresponding argument."
+ tip: Try adding the required argument.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the parameter
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an invocation of a function is
+ missing a required named parameter.
+
+ #### Example
+
+ The following code produces this diagnostic because the invocation of `f`
+ doesn't include a value for the required named parameter `end`:
+
+ ```dart
+ void f(int start, {required int end}) {}
+ void g() {
+ [!f!](3);
+ }
+ ```
+
+ #### Common fixes
+
+ Add a named argument corresponding to the missing required parameter:
+
+ ```dart
+ void f(int start, {required int end}) {}
+ void g() {
+ f(3, end: 5);
+ }
+ ```
+ MIXINS_SUPER_CLASS:
+ template: "'{0}' can't be used in both 'extends' and 'with' clauses."
+ tip: Try removing one of the occurrences.
+ comment: |-
+ Technically this is [IMPLEMENTS_SUPER_CLASS].
+ See https://github.com/dart-lang/sdk/issues/25765#issuecomment-307422593
+
+ Parameters:
+ 0: the name of the class that appears in both "extends" and "with" clauses
+ MIXIN_APPLICATION_CONCRETE_SUPER_INVOKED_MEMBER_TYPE:
+ template: "The super-invoked member '{0}' has the type '{1}', and the concrete member in the class has the type '{2}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the super-invoked member
+ 1: the display name of the type of the super-invoked member in the mixin
+ 2: the display name of the type of the concrete member in the class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a mixin that invokes a method
+ using `super` is used in a class where the concrete implementation of that
+ method has a different signature than the signature defined for that method
+ by the mixin's `on` type. The reason this is an error is because the
+ invocation in the mixin might invoke the method in a way that's
+ incompatible with the method that will actually be executed.
+
+ #### Example
+
+ The following code produces this diagnostic because the class `C` uses the
+ mixin `M`, the mixin `M` invokes `foo` using `super`, and the abstract
+ version of `foo` declared in `I` (the mixin's `on` type) doesn't have the
+ same signature as the concrete version of `foo` declared in `A`:
+
+ ```dart
+ class I {
+ void foo([int? p]) {}
+ }
+
+ class A {
+ void foo(int p) {}
+ }
+
+ abstract class B extends A implements I {
+ @override
+ void foo([int? p]);
+ }
+
+ mixin M on I {
+ void bar() {
+ super.foo(42);
+ }
+ }
+
+ abstract class C extends B with [!M!] {}
+ ```
+
+ #### Common fixes
+
+ If the class doesn't need to use the mixin, then remove it from the `with`
+ clause:
+
+ ```dart
+ class I {
+ void foo([int? p]) {}
+ }
+
+ class A {
+ void foo(int? p) {}
+ }
+
+ abstract class B extends A implements I {
+ @override
+ void foo([int? p]);
+ }
+
+ mixin M on I {
+ void bar() {
+ super.foo(42);
+ }
+ }
+
+ abstract class C extends B {}
+ ```
+
+ If the class needs to use the mixin, then ensure that there's a concrete
+ implementation of the method that conforms to the signature expected by the
+ mixin:
+
+ ```dart
+ class I {
+ void foo([int? p]) {}
+ }
+
+ class A {
+ void foo(int? p) {}
+ }
+
+ abstract class B extends A implements I {
+ @override
+ void foo([int? p]) {
+ super.foo(p);
+ }
+ }
+
+ mixin M on I {
+ void bar() {
+ super.foo(42);
+ }
+ }
+
+ abstract class C extends B with M {}
+ ```
+ MIXIN_APPLICATION_NOT_IMPLEMENTED_INTERFACE:
+ template: "'{0}' can't be mixed onto '{1}' because '{1}' doesn't implement '{2}'."
+ tip: "Try extending the class '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the display name of the mixin
+ 1: the display name of the superclass
+ 2: the display name of the type that is not implemented
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a mixin that has a superclass
+ constraint is used in a [mixin application][] with a superclass that
+ doesn't implement the required constraint.
+
+ #### Example
+
+ The following code produces this diagnostic because the mixin `M` requires
+ that the class to which it's applied be a subclass of `A`, but `Object`
+ isn't a subclass of `A`:
+
+ ```dart
+ class A {}
+
+ mixin M on A {}
+
+ class X = Object with [!M!];
+ ```
+
+ #### Common fixes
+
+ If you need to use the mixin, then change the superclass to be either the
+ same as or a subclass of the superclass constraint:
+
+ ```dart
+ class A {}
+
+ mixin M on A {}
+
+ class X = A with M;
+ ```
+ MIXIN_APPLICATION_NO_CONCRETE_SUPER_INVOKED_MEMBER:
+ template: "The class doesn't have a concrete implementation of the super-invoked member '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the display name of the member without a concrete implementation
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a [mixin application][] contains
+ an invocation of a member from its superclass, and there's no concrete
+ member of that name in the mixin application's superclass.
+
+ #### Example
+
+ The following code produces this diagnostic because the mixin `M` contains
+ the invocation `super.m()`, and the class `A`, which is the superclass of
+ the [mixin application][] `A+M`, doesn't define a concrete implementation
+ of `m`:
+
+ ```dart
+ abstract class A {
+ void m();
+ }
+
+ mixin M on A {
+ void bar() {
+ super.m();
+ }
+ }
+
+ abstract class B extends A with [!M!] {}
+ ```
+
+ #### Common fixes
+
+ If you intended to apply the mixin `M` to a different class, one that has a
+ concrete implementation of `m`, then change the superclass of `B` to that
+ class:
+
+ ```dart
+ abstract class A {
+ void m();
+ }
+
+ mixin M on A {
+ void bar() {
+ super.m();
+ }
+ }
+
+ class C implements A {
+ void m() {}
+ }
+
+ abstract class B extends C with M {}
+ ```
+
+ If you need to make `B` a subclass of `A`, then add a concrete
+ implementation of `m` in `A`:
+
+ ```dart
+ abstract class A {
+ void m() {}
+ }
+
+ mixin M on A {
+ void bar() {
+ super.m();
+ }
+ }
+
+ abstract class B extends A with M {}
+ ```
+ MIXIN_CLASS_DECLARES_CONSTRUCTOR:
+ template: "The class '{0}' can't be used as a mixin because it declares a constructor."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the mixin that is invalid
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class is used as a mixin and
+ the mixed-in class defines a constructor.
+
+ #### Example
+
+ The following code produces this diagnostic because the class `A`, which
+ defines a constructor, is being used as a mixin:
+
+ ```dart
+ class A {
+ A();
+ }
+
+ class B with [!A!] {}
+ ```
+
+ #### Common fixes
+
+ If it's possible to convert the class to a mixin, then do so:
+
+ ```dart
+ mixin A {
+ }
+
+ class B with A {}
+ ```
+
+ If the class can't be a mixin and it's possible to remove the constructor,
+ then do so:
+
+ ```dart
+ class A {
+ }
+
+ class B with A {}
+ ```
+
+ If the class can't be a mixin and you can't remove the constructor, then
+ try extending or implementing the class rather than mixing it in:
+
+ ```dart
+ class A {
+ A();
+ }
+
+ class B extends A {}
+ ```
+ MIXIN_DECLARES_CONSTRUCTOR:
+ template: "Mixins can't declare constructors."
+ comment: |-
+ The <i>mixinMember</i> production allows the same instance or static
+ members that a class would allow, but no constructors (for now).
+ MIXIN_INFERENCE_INCONSISTENT_MATCHING_CLASSES:
+ template: "Type parameters couldn't be inferred for the mixin '{0}' because the base class implements the mixin's supertype constraint '{1}' in multiple conflicting ways"
+ MIXIN_INFERENCE_NO_MATCHING_CLASS:
+ template: "Type parameters couldn't be inferred for the mixin '{0}' because the base class doesn't implement the mixin's supertype constraint '{1}'"
+ MIXIN_INFERENCE_NO_POSSIBLE_SUBSTITUTION:
+ template: "Type parameters couldn't be inferred for the mixin '{0}' because no type parameter substitution could be found matching the mixin's supertype constraints"
+ MIXIN_INHERITS_FROM_NOT_OBJECT:
+ template: "The class '{0}' can't be used as a mixin because it extends a class other than 'Object'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the mixin that is invalid
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class that extends a class
+ other than `Object` is used as a mixin.
+
+ #### Example
+
+ The following code produces this diagnostic because the class `B`, which
+ extends `A`, is being used as a mixin by `C`:
+
+ ```dart
+ class A {}
+
+ class B extends A {}
+
+ class C with [!B!] {}
+ ```
+
+ #### Common fixes
+
+ If the class being used as a mixin can be changed to extend `Object`, then
+ change it:
+
+ ```dart
+ class A {}
+
+ class B {}
+
+ class C with B {}
+ ```
+
+ If the class being used as a mixin can't be changed and the class that's
+ using it extends `Object`, then extend the class being used as a mixin:
+
+ ```dart
+ class A {}
+
+ class B extends A {}
+
+ class C extends B {}
+ ```
+
+ If the class doesn't extend `Object` or if you want to be able to mix in
+ the behavior from `B` in other places, then create a real mixin:
+
+ ```dart
+ class A {}
+
+ mixin M on A {}
+
+ class B extends A with M {}
+
+ class C extends A with M {}
+ ```
+ MIXIN_INSTANTIATE:
+ template: "Mixins can't be instantiated."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a mixin is instantiated.
+
+ #### Example
+
+ The following code produces this diagnostic because the mixin `M` is being
+ instantiated:
+
+ ```dart
+ mixin M {}
+
+ var m = [!M!]();
+ ```
+
+ #### Common fixes
+
+ If you intend to use an instance of a class, then use the name of that
+ class in place of the name of the mixin.
+ MIXIN_OF_NON_CLASS:
+ template: Classes can only mix in mixins and classes.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name in a `with` clause is
+ defined to be something other than a mixin or a class.
+
+ #### Examples
+
+ The following code produces this diagnostic because `F` is defined to be a
+ function type:
+
+ ```dart
+ typedef F = int Function(String);
+
+ class C with [!F!] {}
+ ```
+
+ #### Common fixes
+
+ Remove the invalid name from the list, possibly replacing it with the name
+ of the intended mixin or class:
+
+ ```dart
+ typedef F = int Function(String);
+
+ class C {}
+ ```
+ MIXIN_SUPER_CLASS_CONSTRAINT_DEFERRED_CLASS:
+ template: "Deferred classes can't be used as super-class constraints."
+ tip: Try changing the import to not be deferred.
+ comment: No parameters.
+ MIXIN_SUPER_CLASS_CONSTRAINT_NON_INTERFACE:
+ template: Only classes and mixins can be used as superclass constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a type following the `on`
+ keyword in a mixin declaration is neither a class nor a mixin.
+
+ #### Examples
+
+ The following code produces this diagnostic because `F` is neither a class
+ nor a mixin:
+
+ ```dart
+ typedef F = void Function();
+
+ mixin M on [!F!] {}
+ ```
+
+ #### Common fixes
+
+ If the type was intended to be a class but was mistyped, then replace the
+ name.
+
+ Otherwise, remove the type from the `on` clause.
+ MIXIN_WITH_NON_CLASS_SUPERCLASS:
+ template: Mixin can only be applied to class.
+ comment: |-
+ 9.1 Mixin Application: It is a compile-time error if <i>S</i> does not
+ denote a class available in the immediately enclosing scope.
+ MULTIPLE_REDIRECTING_CONSTRUCTOR_INVOCATIONS:
+ template: "Constructors can have at most one 'this' redirection."
+ tip: Try removing all but one of the redirections.
+ comment: |-
+ 7.6.1 Generative Constructors: A generative constructor may be redirecting,
+ in which case its only action is to invoke another generative constructor.
+ MULTIPLE_SUPER_INITIALIZERS:
+ template: "A constructor can have at most one 'super' initializer."
+ tip: "Try removing all but one of the 'super' initializers."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the initializer list of a
+ constructor contains more than one invocation of a constructor from the
+ superclass. The initializer list is required to have exactly one such call,
+ which can either be explicit or implicit.
+
+ #### Example
+
+ The following code produces this diagnostic because the initializer list
+ for `B`’s constructor invokes both the constructor `one` and the
+ constructor `two` from the superclass `A`:
+
+ ```dart
+ class A {
+ int? x;
+ String? s;
+ A.one(this.x);
+ A.two(this.s);
+ }
+
+ class B extends A {
+ B() : super.one(0), [!super.two('')!];
+ }
+ ```
+
+ #### Common fixes
+
+ If one of the super constructors will initialize the instance fully, then
+ remove the other:
+
+ ```dart
+ class A {
+ int? x;
+ String? s;
+ A.one(this.x);
+ A.two(this.s);
+ }
+
+ class B extends A {
+ B() : super.one(0);
+ }
+ ```
+
+ If the initialization achieved by one of the super constructors can be
+ performed in the body of the constructor, then remove its super invocation
+ and perform the initialization in the body:
+
+ ```dart
+ class A {
+ int? x;
+ String? s;
+ A.one(this.x);
+ A.two(this.s);
+ }
+
+ class B extends A {
+ B() : super.one(0) {
+ s = '';
+ }
+ }
+ ```
+
+ If the initialization can only be performed in a constructor in the
+ superclass, then either add a new constructor or modify one of the existing
+ constructors so there's a constructor that allows all the required
+ initialization to occur in a single call:
+
+ ```dart
+ class A {
+ int? x;
+ String? s;
+ A.one(this.x);
+ A.two(this.s);
+ A.three(this.x, this.s);
+ }
+
+ class B extends A {
+ B() : super.three(0, '');
+ }
+ ```
+ NEW_WITH_UNDEFINED_CONSTRUCTOR:
+ template: "The class '{0}' doesn't have a constructor named '{1}'."
+ tip: "Try invoking a different constructor, or define a constructor named '{1}'."
+ comment: |-
+ 12.11.1 New: If <i>T</i> is a class or parameterized type accessible in the
+ current scope then:
+ 1. If <i>e</i> is of the form <i>new T.id(a<sub>1</sub>, …,
+ a<sub>n</sub>, x<sub>n+1</sub>: a<sub>n+1</sub>, …,
+ x<sub>n+k</sub>: a<sub>n+k</sub>)</i> it is a static warning if
+ <i>T.id</i> is not the name of a constructor declared by the type
+ <i>T</i>.
+ If <i>e</i> of the form <i>new T(a<sub>1</sub>, …, a<sub>n</sub>,
+ x<sub>n+1</sub>: a<sub>n+1</sub>, …, x<sub>n+k</sub>:
+ a<sub>n+kM/sub>)</i> it is a static warning if the type <i>T</i> does not
+ declare a constructor with the same name as the declaration of <i>T</i>.
+ NEW_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT:
+ template: "The class '{0}' doesn't have an unnamed constructor."
+ tip: "Try using one of the named constructors defined in '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the class being instantiated
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an unnamed constructor is
+ invoked on a class that defines named constructors but the class doesn’t
+ have an unnamed constructor.
+
+ #### Examples
+
+ The following code produces this diagnostic because `A` doesn't define an
+ unnamed constructor:
+
+ ```dart
+ class A {
+ A.a();
+ }
+
+ A f() => [!A!]();
+ ```
+
+ #### Common fixes
+
+ If one of the named constructors does what you need, then use it:
+
+ ```dart
+ class A {
+ A.a();
+ }
+
+ A f() => A.a();
+ ```
+
+ If none of the named constructors does what you need, and you're able to
+ add an unnamed constructor, then add the constructor:
+
+ ```dart
+ class A {
+ A();
+ A.a();
+ }
+
+ A f() => A();
+ ```
+ NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_FIVE_PLUS:
+ sharedName: NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER
+ template: "Missing concrete implementations of '{0}', '{1}', '{2}', '{3}', and {4} more."
+ tip: Try implementing the missing methods, or make the class abstract.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the first member
+ 1: the name of the second member
+ 2: the name of the third member
+ 3: the name of the fourth member
+ 4: the number of additional missing members that aren't listed
+ NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_FOUR:
+ sharedName: NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER
+ template: "Missing concrete implementations of '{0}', '{1}', '{2}', and '{3}'."
+ tip: Try implementing the missing methods, or make the class abstract.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the first member
+ 1: the name of the second member
+ 2: the name of the third member
+ 3: the name of the fourth member
+ NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_ONE:
+ sharedName: NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER
+ template: "Missing concrete implementation of '{0}'."
+ tip: Try implementing the missing method, or make the class abstract.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a concrete class inherits one or
+ more abstract members, and doesn't provide or inherit an implementation for
+ at least one of those abstract members.
+
+ #### Examples
+
+ The following code produces this diagnostic because the class `B` doesn't
+ have a concrete implementation of `m`:
+
+ ```dart
+ abstract class A {
+ void m();
+ }
+
+ class [!B!] extends A {}
+ ```
+
+ #### Common fixes
+
+ If the subclass can provide a concrete implementation for some or all of
+ the abstract inherited members, then add the concrete implementations:
+
+ ```dart
+ abstract class A {
+ void m();
+ }
+
+ class B extends A {
+ void m() {}
+ }
+ ```
+
+ If there is a mixin that provides an implementation of the inherited
+ methods, then apply the mixin to the subclass:
+
+ ```dart
+ abstract class A {
+ void m();
+ }
+
+ class B extends A with M {}
+
+ mixin M {
+ void m() {}
+ }
+ ```
+
+ If the subclass can't provide a concrete implementation for all of the
+ abstract inherited members, then mark the subclass as being abstract:
+
+ ```dart
+ abstract class A {
+ void m();
+ }
+
+ abstract class B extends A {}
+ ```
+ NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_THREE:
+ sharedName: NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER
+ template: "Missing concrete implementations of '{0}', '{1}', and '{2}'."
+ tip: Try implementing the missing methods, or make the class abstract.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the first member
+ 1: the name of the second member
+ 2: the name of the third member
+ NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_TWO:
+ sharedName: NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER
+ template: "Missing concrete implementations of '{0}' and '{1}'."
+ tip: Try implementing the missing methods, or make the class abstract.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the first member
+ 1: the name of the second member
+ NON_BOOL_CONDITION:
+ template: "Conditions must have a static type of 'bool'."
+ tip: Try changing the condition.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a condition, such as an `if` or
+ `while` loop, doesn't have the static type `bool`.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` has the static type
+ `int`:
+
+ ```dart
+ void f(int x) {
+ if ([!x!]) {
+ // ...
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Change the condition so that it produces a Boolean value:
+
+ ```dart
+ void f(int x) {
+ if (x == 0) {
+ // ...
+ }
+ }
+ ```
+ NON_BOOL_EXPRESSION:
+ template: "The expression in an assert must be of type 'bool'."
+ tip: Try changing the expression.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the first expression in an
+ assert has a type other than `bool`.
+
+ #### Examples
+
+ The following code produces this diagnostic because the type of `p` is
+ `int`, but a `bool` is required:
+
+ ```dart
+ void f(int p) {
+ assert([!p!]);
+ }
+ ```
+
+ #### Common fixes
+
+ Change the expression so that it has the type `bool`:
+
+ ```dart
+ void f(int p) {
+ assert(p > 0);
+ }
+ ```
+ NON_BOOL_NEGATION_EXPRESSION:
+ template: "A negation operand must have a static type of 'bool'."
+ tip: "Try changing the operand to the '!' operator."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the operand of the unary
+ negation operator (`!`) doesn't have the type `bool`.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` is an `int` when it
+ must be a `bool`:
+
+ ```dart
+ int x = 0;
+ bool y = ![!x!];
+ ```
+
+ #### Common fixes
+
+ Replace the operand with an expression that has the type `bool`:
+
+ ```dart
+ int x = 0;
+ bool y = !(x > 0);
+ ```
+ NON_BOOL_OPERAND:
+ template: "The operands of the operator '{0}' must be assignable to 'bool'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the lexeme of the logical operator
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when one of the operands of either
+ the `&&` or `||` operator doesn't have the type `bool`.
+
+ #### Examples
+
+ The following code produces this diagnostic because `a` isn't a Boolean
+ value:
+
+ ```dart
+ int a = 3;
+ bool b = [!a!] || a > 1;
+ ```
+
+ #### Common fixes
+
+ Change the operand to a Boolean value:
+
+ ```dart
+ int a = 3;
+ bool b = a == 0 || a > 1;
+ ```
+ NON_CONSTANT_ANNOTATION_CONSTRUCTOR:
+ template: Annotation creation can only call a const constructor.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an annotation is the invocation
+ of an existing constructor even though the invoked constructor isn't a
+ const constructor.
+
+ #### Example
+
+ The following code produces this diagnostic because the constructor for `C`
+ isn't a const constructor:
+
+ ```dart
+ [!@C()!]
+ void f() {
+ }
+
+ class C {
+ C();
+ }
+ ```
+
+ #### Common fixes
+
+ If it's valid for the class to have a const constructor, then create a
+ const constructor that can be used for the annotation:
+
+ ```dart
+ @C()
+ void f() {
+ }
+
+ class C {
+ const C();
+ }
+ ```
+
+ If it isn't valid for the class to have a const constructor, then either
+ remove the annotation or use a different class for the annotation.
+ NON_CONSTANT_CASE_EXPRESSION:
+ template: Case expressions must be constant.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the expression in a `case`
+ clause isn't a constant expression.
+
+ #### Examples
+
+ The following code produces this diagnostic because `j` isn't a constant:
+
+ ```dart
+ void f(int i, int j) {
+ switch (i) {
+ case [!j!]:
+ // ...
+ break;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Either make the expression a constant expression, or rewrite the `switch`
+ statement as a sequence of `if` statements:
+
+ ```dart
+ void f(int i, int j) {
+ if (i == j) {
+ // ...
+ }
+ }
+ ```
+ NON_CONSTANT_CASE_EXPRESSION_FROM_DEFERRED_LIBRARY:
+ template: "Constant values from a deferred library can't be used as a case expression."
+ tip: Try re-writing the switch as a series of if statements, or changing the import to not be deferred.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the expression in a case clause
+ references a constant from a library that is imported using a deferred
+ import. In order for switch statements to be compiled efficiently, the
+ constants referenced in case clauses need to be available at compile time,
+ and constants from deferred libraries aren't available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ Given a file (`a.dart`) that defines the constant `zero`:
+
+ ```dart
+ %uri="lib/a.dart"
+ const zero = 0;
+ ```
+
+ The following code produces this diagnostic because the library `a.dart` is
+ imported using a `deferred` import, and the constant `a.zero`, declared in
+ the imported library, is used in a case clause:
+
+ ```dart
+ import 'a.dart' deferred as a;
+
+ void f(int x) {
+ switch (x) {
+ case [!a.zero!]:
+ // ...
+ break;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If you need to reference the constant from the imported library, then
+ remove the `deferred` keyword:
+
+ ```dart
+ import 'a.dart' as a;
+
+ void f(int x) {
+ switch (x) {
+ case a.zero:
+ // ...
+ break;
+ }
+ }
+ ```
+
+ If you need to reference the constant from the imported library and also
+ need the imported library to be deferred, then rewrite the switch statement
+ as a sequence of `if` statements:
+
+ ```dart
+ import 'a.dart' deferred as a;
+
+ void f(int x) {
+ if (x == a.zero) {
+ // ...
+ }
+ }
+ ```
+
+ If you don't need to reference the constant, then replace the case
+ expression:
+
+ ```dart
+ void f(int x) {
+ switch (x) {
+ case 0:
+ // ...
+ break;
+ }
+ }
+ ```
+ NON_CONSTANT_DEFAULT_VALUE:
+ template: The default value of an optional parameter must be constant.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an optional parameter, either
+ named or positional, has a default value that isn't a compile-time
+ constant.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ %language=2.9
+ var defaultValue = 3;
+
+ void f([int value = [!defaultValue!]]) {}
+ ```
+
+ #### Common fixes
+
+ If the default value can be converted to be a constant, then convert it:
+
+ ```dart
+ %language=2.9
+ const defaultValue = 3;
+
+ void f([int value = defaultValue]) {}
+ ```
+
+ If the default value needs to change over time, then apply the default
+ value inside the function:
+
+ ```dart
+ %language=2.9
+ var defaultValue = 3;
+
+ void f([int value]) {
+ value ??= defaultValue;
+ }
+ ```
+ NON_CONSTANT_DEFAULT_VALUE_FROM_DEFERRED_LIBRARY:
+ template: "Constant values from a deferred library can't be used as a default parameter value."
+ tip: Try leaving the default as null and initializing the parameter inside the function body.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the default value of an optional
+ parameter uses a constant from a library imported using a deferred import.
+ Default values need to be available at compile time, and constants from
+ deferred libraries aren't available at compile time.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ Given a file (`a.dart`) that defines the constant `zero`:
+
+ ```dart
+ %uri="lib/a.dart"
+ const zero = 0;
+ ```
+
+ The following code produces this diagnostic because `zero` is declared in a
+ library imported using a deferred import:
+
+ ```dart
+ import 'a.dart' deferred as a;
+
+ void f({int x = [!a.zero!]}) {}
+ ```
+
+ #### Common fixes
+
+ If you need to reference the constant from the imported library, then
+ remove the `deferred` keyword:
+
+ ```dart
+ import 'a.dart' as a;
+
+ void f({int x = a.zero}) {}
+ ```
+
+ If you don't need to reference the constant, then replace the default
+ value:
+
+ ```dart
+ void f({int x = 0}) {}
+ ```
+ NON_CONSTANT_LIST_ELEMENT:
+ template: The values in a const list literal must be constants.
+ tip: "Try removing the keyword 'const' from the list literal."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an element in a constant list
+ literal isn't a constant value. The list literal can be constant either
+ explicitly (because it's prefixed by the `const` keyword) or implicitly
+ (because it appears in a [constant context][]).
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` isn't a constant,
+ even though it appears in an implicitly constant list literal:
+
+ ```dart
+ var x = 2;
+ var y = const <int>[0, 1, [!x!]];
+ ```
+
+ #### Common fixes
+
+ If the list needs to be a constant list, then convert the element to be a
+ constant. In the example above, you might add the `const` keyword to the
+ declaration of `x`:
+
+ ```dart
+ const x = 2;
+ var y = const <int>[0, 1, x];
+ ```
+
+ If the expression can't be made a constant, then the list can't be a
+ constant either, so you must change the code so that the list isn't a
+ constant. In the example above this means removing the `const` keyword
+ before the list literal:
+
+ ```dart
+ var x = 2;
+ var y = <int>[0, 1, x];
+ ```
+ NON_CONSTANT_MAP_ELEMENT:
+ template: The elements in a const map literal must be constant.
+ tip: "Try removing the keyword 'const' from the map literal."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an `if` element or a spread
+ element in a constant map isn't a constant element.
+
+ #### Examples
+
+ The following code produces this diagnostic because it's attempting to
+ spread a non-constant map:
+
+ ```dart
+ var notConst = <int, int>{};
+ var map = const <int, int>{...[!notConst!]};
+ ```
+
+ Similarly, the following code produces this diagnostic because the
+ condition in the `if` element isn't a constant expression:
+
+ ```dart
+ bool notConst = true;
+ var map = const <int, int>{if ([!notConst!]) 1 : 2};
+ ```
+
+ #### Common fixes
+
+ If the map needs to be a constant map, then make the elements constants.
+ In the spread example, you might do that by making the collection being
+ spread a constant:
+
+ ```dart
+ const notConst = <int, int>{};
+ var map = const <int, int>{...notConst};
+ ```
+
+ If the map doesn't need to be a constant map, then remove the `const`
+ keyword:
+
+ ```dart
+ bool notConst = true;
+ var map = <int, int>{if (notConst) 1 : 2};
+ ```
+ NON_CONSTANT_MAP_KEY:
+ template: The keys in a const map literal must be constant.
+ tip: "Try removing the keyword 'const' from the map literal."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a key in a constant map literal
+ isn't a constant value.
+
+ #### Examples
+
+ The following code produces this diagnostic beause `a` isn't a constant:
+
+ ```dart
+ var a = 'a';
+ var m = const {[!a!]: 0};
+ ```
+
+ #### Common fixes
+
+ If the map needs to be a constant map, then make the key a constant:
+
+ ```dart
+ const a = 'a';
+ var m = const {a: 0};
+ ```
+
+ If the map doesn't need to be a constant map, then remove the `const`
+ keyword:
+
+ ```dart
+ var a = 'a';
+ var m = {a: 0};
+ ```
+ NON_CONSTANT_MAP_VALUE:
+ template: The values in a const map literal must be constant.
+ tip: "Try removing the keyword 'const' from the map literal."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a value in a constant map
+ literal isn't a constant value.
+
+ #### Examples
+
+ The following code produces this diagnostic because `a` isn't a constant:
+
+ ```dart
+ var a = 'a';
+ var m = const {0: [!a!]};
+ ```
+
+ #### Common fixes
+
+ If the map needs to be a constant map, then make the key a constant:
+
+ ```dart
+ const a = 'a';
+ var m = const {0: a};
+ ```
+
+ If the map doesn't need to be a constant map, then remove the `const`
+ keyword:
+
+ ```dart
+ var a = 'a';
+ var m = {0: a};
+ ```
+ NON_CONSTANT_SET_ELEMENT:
+ template: The values in a const set literal must be constants.
+ tip: "Try removing the keyword 'const' from the set literal."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constant set literal contains
+ an element that isn't a compile-time constant.
+
+ #### Examples
+
+ The following code produces this diagnostic because `i` isn't a constant:
+
+ ```dart
+ var i = 0;
+
+ var s = const {[!i!]};
+ ```
+
+ #### Common fixes
+
+ If the element can be changed to be a constant, then change it:
+
+ ```dart
+ const i = 0;
+
+ var s = const {i};
+ ```
+
+ If the element can't be a constant, then remove the keyword `const`:
+
+ ```dart
+ var i = 0;
+
+ var s = {i};
+ ```
+ NON_CONST_MAP_AS_EXPRESSION_STATEMENT:
+ template: "A non-constant map or set literal without type arguments can't be used as an expression statement."
+ comment: |-
+ 13.2 Expression Statements: It is a compile-time error if a non-constant
+ map literal that has no explicit type arguments appears in a place where a
+ statement is expected.
+ NON_GENERATIVE_CONSTRUCTOR:
+ template: "The generative constructor '{0}' is expected, but a factory was found."
+ tip: Try calling a different constructor of the superclass, or making the called constructor not be a factory constructor.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the non-generative constructor
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the initializer list of a
+ constructor invokes a constructor from the superclass, and the invoked
+ constructor is a factory constructor. Only a generative constructor can be
+ invoked in the initializer list.
+
+ #### Example
+
+ The following code produces this diagnostic because the invocation of the
+ constructor `super.one()` is invoking a factory constructor:
+
+ ```dart
+ class A {
+ factory A.one() = B;
+ A.two();
+ }
+
+ class B extends A {
+ B() : [!super.one()!];
+ }
+ ```
+
+ #### Common fixes
+
+ Change the super invocation to invoke a generative constructor:
+
+ ```dart
+ class A {
+ factory A.one() = B;
+ A.two();
+ }
+
+ class B extends A {
+ B() : super.two();
+ }
+ ```
+
+ If the generative constructor is the unnamed constructor, and if there are
+ no arguments being passed to it, then you can remove the super invocation.
+ NON_GENERATIVE_IMPLICIT_CONSTRUCTOR:
+ template: "The unnamed constructor of superclass '{0}' (called by the default constructor of '{1}') must be a generative constructor, but factory found."
+ tip: "Try adding an explicit constructor that has a different superinitializer or changing the superclass constructor '{2}' to not be a factory constructor."
+ comment: |-
+ An error code for when a class has no explicit constructor, and therefore
+ a constructor is implicitly defined which uses a factory as a
+ superinitializer. See [NON_GENERATIVE_CONSTRUCTOR].
+
+ Parameters:
+ 0: the name of the superclass
+ 1: the name of the current class
+ 2: the implicitly called factory constructor of the superclass
+ NON_SYNC_FACTORY:
+ template: "Factory bodies can't use 'async', 'async*', or 'sync*'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the body of a factory
+ constructor is marked with `async`, `async*`, or `sync*`. All constructors,
+ including factory constructors, are required to return an instance of the
+ class in which they're declared, not a `Future`, `Stream`, or `Iterator`.
+
+ #### Example
+
+ The following code produces this diagnostic because the body of the factory
+ constructor is marked with `async`:
+
+ ```dart
+ class C {
+ factory C() [!async!] {
+ return C._();
+ }
+ C._();
+ }
+ ```
+
+ #### Common fixes
+
+ If the member must be declared as a factory constructor, then remove the
+ keyword appearing before the body:
+
+ ```dart
+ class C {
+ factory C() {
+ return C._();
+ }
+ C._();
+ }
+ ```
+
+ If the member must return something other than an instance of the enclosing
+ class, then make the member a static method:
+
+ ```dart
+ class C {
+ static Future<C> m() async {
+ return C._();
+ }
+ C._();
+ }
+ ```
+ NON_TYPE_AS_TYPE_ARGUMENT:
+ template: "The name '{0}' isn't a type so it can't be used as a type argument."
+ tip: "Try correcting the name to an existing type, or defining a type named '{0}'."
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name appearing where a type is expected
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an identifier that isn't a type
+ is used as a type argument.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` is a variable, not
+ a type:
+
+ ```dart
+ var x = 0;
+ List<[!x!]> xList = [];
+ ```
+
+ #### Common fixes
+
+ Change the type argument to be a type:
+
+ ```dart
+ var x = 0;
+ List<int> xList = [];
+ ```
+ NON_TYPE_IN_CATCH_CLAUSE:
+ template: "The name '{0}' isn't a type and can't be used in an on-catch clause."
+ tip: Try correcting the name to match an existing class.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the non-type element
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the identifier following the
+ `on` in a `catch` clause is defined to be something other than a type.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` is a function, not
+ a type:
+
+ ```dart
+ %language=2.9
+ void f() {
+ try {
+ // ...
+ } on [!f!] {
+ // ...
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Change the name to the type of object that should be caught:
+
+ ```dart
+ %language=2.9
+ void f() {
+ try {
+ // ...
+ } on FormatException {
+ // ...
+ }
+ }
+ ```
+ NON_VOID_RETURN_FOR_OPERATOR:
+ template: "The return type of the operator []= must be 'void'."
+ tip: "Try changing the return type to 'void'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a declaration of the operator
+ `[]=` has a return type other than `void`.
+
+ #### Example
+
+ The following code produces this diagnostic because the declaration of the
+ operator `[]=` has a return type of `int`:
+
+ ```dart
+ class C {
+ [!int!] operator []=(int index, int value) => 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Change the return type to `void`:
+
+ ```dart
+ class C {
+ void operator []=(int index, int value) => 0;
+ }
+ ```
+ NON_VOID_RETURN_FOR_SETTER:
+ template: "The return type of the setter must be 'void' or absent."
+ tip: Try removing the return type, or define a method rather than a setter.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a setter is defined with a
+ return type other than `void`.
+
+ #### Example
+
+ The following code produces this diagnostic because the setter `p` has a
+ return type of `int`:
+
+ ```dart
+ class C {
+ [!int!] set p(int i) => 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Change the return type to `void` or omit the return type:
+
+ ```dart
+ class C {
+ set p(int i) => 0;
+ }
+ ```
+ NOT_ASSIGNED_POTENTIALLY_NON_NULLABLE_LOCAL_VARIABLE:
+ template: "The non-nullable local variable '{0}' must be assigned before it can be used."
+ tip: "Try giving it an initializer expression, or ensure that it's assigned on every execution path."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the variable that is invalid
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a local variable is referenced
+ and has all these characteristics:
+ - Has a type that's [potentially non-nullable][].
+ - Doesn't have an initializer.
+ - Isn't marked as `late`.
+ - The analyzer can't prove that the local variable will be assigned before
+ the reference based on the specification of [definite assignment][].
+
+ #### Example
+
+ The following code produces this diagnostic because `x` can't have a value
+ of `null`, but is referenced before a value was assigned to it:
+
+ ```dart
+ String f() {
+ int x;
+ return [!x!].toString();
+ }
+ ```
+
+ The following code produces this diagnostic because the assignment to `x`
+ might not be executed, so it might have a value of `null`:
+
+ ```dart
+ int g(bool b) {
+ int x;
+ if (b) {
+ x = 1;
+ }
+ return [!x!] * 2;
+ }
+ ```
+
+ The following code produces this diagnostic because the analyzer can't
+ prove, based on definite assignment analysis, that `x` won't be referenced
+ without having a value assigned to it:
+
+ ```dart
+ int h(bool b) {
+ int x;
+ if (b) {
+ x = 1;
+ }
+ if (b) {
+ return [!x!] * 2;
+ }
+ return 0;
+ }
+ ```
+
+ #### Common fixes
+
+ If `null` is a valid value, then make the variable nullable:
+
+ ```dart
+ String f() {
+ int? x;
+ return x!.toString();
+ }
+ ```
+
+ If `null` isn’t a valid value, and there's a reasonable default value, then
+ add an initializer:
+
+ ```dart
+ int g(bool b) {
+ int x = 2;
+ if (b) {
+ x = 1;
+ }
+ return x * 2;
+ }
+ ```
+
+ Otherwise, ensure that a value was assigned on every possible code path
+ before the value is accessed:
+
+ ```dart
+ int g(bool b) {
+ int x;
+ if (b) {
+ x = 1;
+ } else {
+ x = 2;
+ }
+ return x * 2;
+ }
+ ```
+
+ You can also mark the variable as `late`, which removes the diagnostic, but
+ if the variable isn't assigned a value before it's accessed, then it
+ results in an exception being thrown at runtime. This approach should only
+ be used if you're sure that the variable will always be assigned, even
+ though the analyzer can't prove it based on definite assignment analysis.
+
+ ```dart
+ int h(bool b) {
+ late int x;
+ if (b) {
+ x = 1;
+ }
+ if (b) {
+ return x * 2;
+ }
+ return 0;
+ }
+ ```
+ NOT_A_TYPE:
+ template: "{0} isn't a type."
+ tip: Try correcting the name to match an existing type.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name that is not a type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name is used as a type but
+ declared to be something other than a type.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` is a function:
+
+ ```dart
+ f() {}
+ g([!f!] v) {}
+ ```
+
+ #### Common fixes
+
+ Replace the name with the name of a type.
+ NOT_BINARY_OPERATOR:
+ template: "'{0}' isn't a binary operator."
+ comment: |-
+ Parameters:
+ 0: the name of the operator that is not a binary operator.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an operator that can only be
+ used as a unary operator is used as a binary operator.
+
+ #### Example
+
+ The following code produces this diagnostic because the operator `~` can
+ only be used as a unary operator:
+
+ ```dart
+ var a = 5 [!~!] 3;
+ ```
+
+ #### Common fixes
+
+ Replace the operator with the correct binary operator:
+
+ ```dart
+ var a = 5 - 3;
+ ```
+ NOT_ENOUGH_POSITIONAL_ARGUMENTS:
+ template: "{0} positional argument(s) expected, but {1} found."
+ tip: Try adding the missing arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the expected number of required arguments
+ 1: the actual number of positional arguments given
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function invocation
+ has fewer positional arguments than the number of required positional
+ parameters.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` declares two
+ required parameters, but only one argument is provided:
+
+ ```dart
+ void f(int a, int b) {}
+ void g() {
+ f[!(0)!];
+ }
+ ```
+
+ #### Common fixes
+
+ Add arguments corresponding to the remaining parameters:
+
+ ```dart
+ void f(int a, int b) {}
+ void g() {
+ f(0, 1);
+ }
+ ```
+ NOT_INITIALIZED_NON_NULLABLE_INSTANCE_FIELD:
+ template: "Non-nullable instance field '{0}' must be initialized."
+ tip: "Try adding an initializer expression, or a generative constructor that initializes it, or mark it 'late'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the field that is not initialized
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a field is declared and has all
+ these characteristics:
+ - Has a type that's [potentially non-nullable][]
+ - Doesn't have an initializer
+ - Isn't marked as `late`
+
+ #### Example
+
+ The following code produces this diagnostic because `x` is implicitly
+ initialized to `null` when it isn't allowed to be `null`:
+
+ ```dart
+ class C {
+ int [!x!];
+ }
+ ```
+
+ Similarly, the following code produces this diagnostic because `x` is
+ implicitly initialized to `null`, when it isn't allowed to be `null`, by
+ one of the constructors, even though it's initialized by other
+ constructors:
+
+ ```dart
+ class C {
+ int x;
+
+ C(this.x);
+
+ [!C!].n();
+ }
+ ```
+
+ #### Common fixes
+
+ If there's a reasonable default value for the field that’s the same for all
+ instances, then add an initializer expression:
+
+ ```dart
+ class C {
+ int x = 0;
+ }
+ ```
+
+ If the value of the field should be provided when an instance is created,
+ then add a constructor that sets the value of the field or update an
+ existing constructor:
+
+ ```dart
+ class C {
+ int x;
+
+ C(this.x);
+ }
+ ```
+
+ You can also mark the field as `late`, which removes the diagnostic, but if
+ the field isn't assigned a value before it's accessed, then it results in
+ an exception being thrown at runtime. This approach should only be used if
+ you're sure that the field will always be assigned before it's referenced.
+
+ ```dart
+ class C {
+ late int x;
+ }
+ ```
+ NOT_INITIALIZED_NON_NULLABLE_INSTANCE_FIELD_CONSTRUCTOR:
+ sharedName: NOT_INITIALIZED_NON_NULLABLE_INSTANCE_FIELD
+ template: "Non-nullable instance field '{0}' must be initialized."
+ tip: "Try adding an initializer expression, or add a field initializer in this constructor, or mark it 'late'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the field that is not initialized
+ NOT_INITIALIZED_NON_NULLABLE_VARIABLE:
+ template: "The non-nullable variable '{0}' must be initialized."
+ tip: Try adding an initializer expression.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the variable that is invalid
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a static field or top-level
+ variable has a type that's non-nullable and doesn't have an initializer.
+ Fields and variables that don't have an initializer are normally
+ initialized to `null`, but the type of the field or variable doesn't allow
+ it to be set to `null`, so an explicit initializer must be provided.
+
+ #### Example
+
+ The following code produces this diagnostic because the field `f` can't be
+ initialized to `null`:
+
+ ```dart
+ class C {
+ static int [!f!];
+ }
+ ```
+
+ Similarly, the following code produces this diagnostic because the
+ top-level variable `v` can't be initialized to `null`:
+
+ ```dart
+ int [!v!];
+ ```
+
+ #### Common fixes
+
+ If the field or variable can't be initialized to `null`, then add an
+ initializer that sets it to a non-null value:
+
+ ```dart
+ class C {
+ static int f = 0;
+ }
+ ```
+
+ If the field or variable should be initialized to `null`, then change the
+ type to be nullable:
+
+ ```dart
+ int? v;
+ ```
+
+ If the field or variable can't be initialized in the declaration but will
+ always be initialized before it's referenced, then mark it as being `late`:
+
+ ```dart
+ class C {
+ static late int f;
+ }
+ ```
+ NOT_INSTANTIATED_BOUND:
+ template: Type parameter bound types must be instantiated.
+ tip: Try adding type arguments to the type parameter bound.
+ comment: No parameters.
+ NOT_ITERABLE_SPREAD:
+ template: "Spread elements in list or set literals must implement 'Iterable'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the static type of the
+ expression of a spread element that appears in either a list literal or a
+ set literal doesn't implement the type `Iterable`.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ var m = <String, int>{'a': 0, 'b': 1};
+ var s = <String>{...[!m!]};
+ ```
+
+ #### Common fixes
+
+ The most common fix is to replace the expression with one that produces an
+ iterable object:
+
+ ```dart
+ var m = <String, int>{'a': 0, 'b': 1};
+ var s = <String>{...m.keys};
+ ```
+ NOT_MAP_SPREAD:
+ template: "Spread elements in map literals must implement 'Map'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the static type of the
+ expression of a spread element that appears in a map literal doesn't
+ implement the type `Map`.
+
+ #### Examples
+
+ The following code produces this diagnostic because `l` isn't a `Map`:
+
+ ```dart
+ var l = <String>['a', 'b'];
+ var m = <int, String>{...[!l!]};
+ ```
+
+ #### Common fixes
+
+ The most common fix is to replace the expression with one that produces a
+ map:
+
+ ```dart
+ var l = <String>['a', 'b'];
+ var m = <int, String>{...l.asMap()};
+ ```
+ NOT_NULL_AWARE_NULL_SPREAD:
+ template: "The Null typed expression can't be used with a non-null-aware spread."
+ comment: No parameters.
+ NO_ANNOTATION_CONSTRUCTOR_ARGUMENTS:
+ template: Annotation creation must have arguments.
+ tip: Try adding an empty argument list.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an annotation consists of a
+ single identifier, but that identifier is the name of a class rather than a
+ variable. To create an instance of the class, the identifier must be
+ followed by an argument list.
+
+ #### Examples
+
+ The following code produces this diagnostic because `C` is a class, and a
+ class can't be used as an annotation without invoking a `const` constructor
+ from the class:
+
+ ```dart
+ class C {
+ const C();
+ }
+
+ [!@C!]
+ var x;
+ ```
+
+ #### Common fixes
+
+ Add the missing argument list:
+
+ ```dart
+ class C {
+ const C();
+ }
+
+ @C()
+ var x;
+ ```
+ NO_COMBINED_SUPER_SIGNATURE:
+ template: "Can't infer missing types in '{0}' from overridden methods: {1}."
+ tip: "Try providing explicit types for this method's parameters and return type."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the class where override error was detected
+ 1: the list of candidate signatures which cannot be combined
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when there is a method declaration
+ for which one or more types needs to be inferred, and those types can't be
+ inferred because none of the overridden methods has a function type that is
+ a supertype of all the other overridden methods, as specified by
+ [override inference][].
+
+ #### Example
+
+ The following code produces this diagnostic because the method `m` declared
+ in the class `C` is missing both the return type and the type of the
+ parameter `a`, and neither of the missing types can be inferred for it:
+
+ ```dart
+ abstract class A {
+ A m(String a);
+ }
+
+ abstract class B {
+ B m(int a);
+ }
+
+ abstract class C implements A, B {
+ [!m!](a);
+ }
+ ```
+
+ In this example, override inference can't be performed because the
+ overridden methods are incompatible in these ways:
+ - Neither parameter type (`String` and `int`) is a supertype of the other.
+ - Neither return type is a subtype of the other.
+
+ #### Common fixes
+
+ If possible, add types to the method in the subclass that are consistent
+ with the types from all the overridden methods:
+
+ ```dart
+ abstract class A {
+ A m(String a);
+ }
+
+ abstract class B {
+ B m(int a);
+ }
+
+ abstract class C implements A, B {
+ C m(Object a);
+ }
+ ```
+ NO_DEFAULT_SUPER_CONSTRUCTOR_EXPLICIT:
+ sharedName: NO_DEFAULT_SUPER_CONSTRUCTOR
+ template: "The superclass '{0}' doesn't have a zero argument constructor."
+ tip: "Try declaring a zero argument constructor in '{0}', or explicitly invoking a different constructor in '{0}'."
+ comment: |-
+ Parameters:
+ 0: the name of the superclass that does not define an implicitly invoked
+ constructor
+ NO_DEFAULT_SUPER_CONSTRUCTOR_IMPLICIT:
+ sharedName: NO_DEFAULT_SUPER_CONSTRUCTOR
+ template: "The superclass '{0}' doesn't have a zero argument constructor."
+ tip: "Try declaring a zero argument constructor in '{0}', or declaring a constructor in {1} that explicitly invokes a constructor in '{0}'."
+ comment: |-
+ Parameters:
+ 0: the name of the superclass that does not define an implicitly invoked
+ constructor
+ 1: the name of the subclass that does not contain any explicit constructors
+ NO_GENERATIVE_CONSTRUCTORS_IN_SUPERCLASS:
+ template: "The class '{0}' cannot extend '{1}' because '{1}' only has factory constructors (no generative constructors), and '{0}' has at least one generative constructor."
+ tip: "Try implementing the class instead, adding a generative (not factory) constructor to the superclass {0}, or a factory constructor to the subclass."
+ comment: |-
+ User friendly specialized error for [NON_GENERATIVE_CONSTRUCTOR]. This
+ handles the case of `class E extends Exception` which will never work
+ because [Exception] has no generative constructors.
+
+ Parameters:
+ 0: the name of the subclass
+ 1: the name of the superclass
+ NULLABLE_TYPE_IN_EXTENDS_CLAUSE:
+ template: "A class can't extend a nullable type."
+ tip: Try removing the question mark.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class declaration uses an
+ `extends` clause to specify a superclass, and the superclass is followed by
+ a `?`.
+
+ It isn't valid to specify a nullable superclass because doing so would have
+ no meaning; it wouldn't change either the interface or implementation being
+ inherited by the class containing the `extends` clause.
+
+ Note, however, that it _is_ valid to use a nullable type as a type argument
+ to the superclass, such as `class A extends B<C?> {}`.
+
+ #### Example
+
+ The following code produces this diagnostic because `A?` is a nullable
+ type, and nullable types can't be used in an `extends` clause:
+
+ ```dart
+ class A {}
+ class B extends [!A?!] {}
+ ```
+
+ #### Common fixes
+
+ Remove the question mark from the type:
+
+ ```dart
+ class A {}
+ class B extends A {}
+ ```
+ NULLABLE_TYPE_IN_IMPLEMENTS_CLAUSE:
+ template: "A class or mixin can't implement a nullable type."
+ tip: Try removing the question mark.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class or mixin declaration has
+ an `implements` clause, and an interface is followed by a `?`.
+
+ It isn't valid to specify a nullable interface because doing so would have
+ no meaning; it wouldn't change the interface being inherited by the class
+ containing the `implements` clause.
+
+ Note, however, that it _is_ valid to use a nullable type as a type argument
+ to the interface, such as `class A implements B<C?> {}`.
+
+
+ #### Example
+
+ The following code produces this diagnostic because `A?` is a nullable
+ type, and nullable types can't be used in an `implements` clause:
+
+ ```dart
+ class A {}
+ class B implements [!A?!] {}
+ ```
+
+ #### Common fixes
+
+ Remove the question mark from the type:
+
+ ```dart
+ class A {}
+ class B implements A {}
+ ```
+ NULLABLE_TYPE_IN_ON_CLAUSE:
+ template: "A mixin can't have a nullable type as a superclass constraint."
+ tip: Try removing the question mark.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a mixin declaration uses an `on`
+ clause to specify a superclass constraint, and the class that's specified
+ is followed by a `?`.
+
+ It isn't valid to specify a nullable superclass constraint because doing so
+ would have no meaning; it wouldn't change the interface being depended on
+ by the mixin containing the `on` clause.
+
+ Note, however, that it _is_ valid to use a nullable type as a type argument
+ to the superclass constraint, such as `mixin A on B<C?> {}`.
+
+
+ #### Example
+
+ The following code produces this diagnostic because `A?` is a nullable type
+ and nullable types can't be used in an `on` clause:
+
+ ```dart
+ class C {}
+ mixin M on [!C?!] {}
+ ```
+
+ #### Common fixes
+
+ Remove the question mark from the type:
+
+ ```dart
+ class C {}
+ mixin M on C {}
+ ```
+ NULLABLE_TYPE_IN_WITH_CLAUSE:
+ template: "A class or mixin can't mix in a nullable type."
+ tip: Try removing the question mark.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class or mixin declaration has
+ a `with` clause, and a mixin is followed by a `?`.
+
+ It isn't valid to specify a nullable mixin because doing so would have no
+ meaning; it wouldn't change either the interface or implementation being
+ inherited by the class containing the `with` clause.
+
+ Note, however, that it _is_ valid to use a nullable type as a type argument
+ to the mixin, such as `class A with B<C?> {}`.
+
+ #### Example
+
+ The following code produces this diagnostic because `A?` is a nullable
+ type, and nullable types can't be used in a `with` clause:
+
+ ```dart
+ mixin M {}
+ class C with [!M?!] {}
+ ```
+
+ #### Common fixes
+
+ Remove the question mark from the type:
+
+ ```dart
+ mixin M {}
+ class C with M {}
+ ```
+ OBJECT_CANNOT_EXTEND_ANOTHER_CLASS:
+ template: "The class 'Object' can't extend any other class."
+ comment: |-
+ 7.9 Superclasses: It is a compile-time error to specify an extends clause
+ for class Object.
+ ON_REPEATED:
+ template: "The type '{0}' can be included in the superclass constraints only once."
+ tip: Try removing all except one occurrence of the type name.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the interface that is implemented more than once
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the same type is listed in the
+ superclass constraints of a mixin multiple times.
+
+ #### Example
+
+ The following code produces this diagnostic because `A` is included twice
+ in the superclass constraints for `M`:
+
+ ```dart
+ mixin M on A, [!A!] {
+ }
+
+ class A {}
+ class B {}
+ ```
+
+ #### Common fixes
+
+ If a different type should be included in the superclass constraints, then
+ replace one of the occurrences with the other type:
+
+ ```dart
+ mixin M on A, B {
+ }
+
+ class A {}
+ class B {}
+ ```
+
+ If no other type was intended, then remove the repeated type name:
+
+ ```dart
+ mixin M on A {
+ }
+
+ class A {}
+ class B {}
+ ```
+ OPTIONAL_PARAMETER_IN_OPERATOR:
+ template: "Optional parameters aren't allowed when defining an operator."
+ tip: Try removing the optional parameters.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when one or more of the parameters in
+ an operator declaration are optional.
+
+ #### Example
+
+ The following code produces this diagnostic because the parameter `other`
+ is an optional parameter:
+
+ ```dart
+ class C {
+ C operator +([[!C? other!]]) => this;
+ }
+ ```
+
+ #### Common fixes
+
+ Make all of the parameters be required parameters:
+
+ ```dart
+ class C {
+ C operator +(C other) => this;
+ }
+ ```
+ PART_OF_DIFFERENT_LIBRARY:
+ template: "Expected this library to be part of '{0}', not '{1}'."
+ tip: "Try including a different part, or changing the name of the library in the part's part-of directive."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of expected library name
+ 1: the non-matching actual library name from the "part of" declaration
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a library attempts to include a
+ file as a part of itself when the other file is a part of a different
+ library.
+
+ #### Example
+
+ Given a file named `part.dart` containing
+
+ ```dart
+ %uri="package:a/part.dart"
+ part of 'library.dart';
+ ```
+
+ The following code, in any file other than `library.dart`, produces this
+ diagnostic because it attempts to include `part.dart` as a part of itself
+ when `part.dart` is a part of a different library:
+
+ ```dart
+ part [!'package:a/part.dart'!];
+ ```
+
+ #### Common fixes
+
+ If the library should be using a different file as a part, then change the
+ URI in the part directive to be the URI of the other file.
+
+ If the part file should be a part of this library, then update the URI (or
+ library name) in the part-of directive to be the URI (or name) of the
+ correct library.
+ PART_OF_NON_PART:
+ template: "The included part '{0}' must have a part-of directive."
+ tip: "Try adding a part-of directive to '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the uri pointing to a non-library declaration
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a part directive is found and
+ the referenced file doesn't have a part-of directive.
+
+ #### Examples
+
+ Given a file (`a.dart`) containing:
+
+ ```dart
+ %uri="lib/a.dart"
+ class A {}
+ ```
+
+ The following code produces this diagnostic because `a.dart` doesn't
+ contain a part-of directive:
+
+ ```dart
+ part [!'a.dart'!];
+ ```
+
+ #### Common fixes
+
+ If the referenced file is intended to be a part of another library, then
+ add a part-of directive to the file:
+
+ ```dart
+ part of 'test.dart';
+
+ class A {}
+ ```
+
+ If the referenced file is intended to be a library, then replace the part
+ directive with an import directive:
+
+ ```dart
+ import 'a.dart';
+ ```
+ PART_OF_UNNAMED_LIBRARY:
+ template: "The library is unnamed. A URI is expected, not a library name '{0}', in the part-of directive."
+ tip: Try changing the part-of directive to a URI, or try including a different part.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the URI of the expected library
+ 1: the non-matching actual library name from the "part of" declaration
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a library that doesn't have a
+ `library` directive (and hence has no name) contains a `part` directive and
+ the `part of` directive in the part file uses a name to specify the library
+ that it's a part of.
+
+ #### Example
+
+ Given a part file named `part_file.dart` containing the following code:
+
+ ```dart
+ %uri="lib/part_file.dart"
+ part of lib;
+ ```
+
+ The following code produces this diagnostic because the library including
+ the part file doesn't have a name even though the part file uses a name to
+ specify which library it's a part of:
+
+ ```dart
+ part [!'part_file.dart'!];
+ ```
+
+ #### Common fixes
+
+ Change the `part of` directive in the part file to specify its library by
+ URI:
+
+ ```dart
+ part of 'test.dart';
+ ```
+ PREFIX_COLLIDES_WITH_TOP_LEVEL_MEMBER:
+ template: "The name '{0}' is already used as an import prefix and can't be used to name a top-level element."
+ tip: Try renaming either the top-level element or the prefix.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the prefix
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name is used as both an import
+ prefix and the name of a top-level declaration in the same library.
+
+ #### Example
+
+ The following code produces this diagnostic because `f` is used as both an
+ import prefix and the name of a function:
+
+ ```dart
+ import 'dart:math' as f;
+
+ int [!f!]() => f.min(0, 1);
+ ```
+
+ #### Common fixes
+
+ If you want to use the name for the import prefix, then rename the
+ top-level declaration:
+
+ ```dart
+ import 'dart:math' as f;
+
+ int g() => f.min(0, 1);
+ ```
+
+ If you want to use the name for the top-level declaration, then rename the
+ import prefix:
+
+ ```dart
+ import 'dart:math' as math;
+
+ int f() => math.min(0, 1);
+ ```
+ PREFIX_IDENTIFIER_NOT_FOLLOWED_BY_DOT:
+ template: "The name '{0}' refers to an import prefix, so it must be followed by '.'."
+ tip: Try correcting the name to refer to something other than a prefix, or renaming the prefix.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the prefix
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an import prefix is used by
+ itself, without accessing any of the names declared in the libraries
+ associated with the prefix. Prefixes aren't variables, and therefore can't
+ be used as a value.
+
+ #### Example
+
+ The following code produces this diagnostic because the prefix `math` is
+ being used as if it were a variable:
+
+ ```dart
+ import 'dart:math' as math;
+
+ void f() {
+ print([!math!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If the code is incomplete, then reference something in one of the libraries
+ associated with the prefix:
+
+ ```dart
+ import 'dart:math' as math;
+
+ void f() {
+ print(math.pi);
+ }
+ ```
+
+ If the name is wrong, then correct the name.
+ PREFIX_SHADOWED_BY_LOCAL_DECLARATION:
+ template: "The prefix '{0}' can't be used here because it is shadowed by a local declaration."
+ tip: Try renaming either the prefix or the local declaration.
+ comment: |-
+ From the `Static Types` section of the spec:
+
+ A type T is malformed if:
+ - T has the form id or the form prefix.id, and in the enclosing lexical
+ scope, the name id (respectively prefix.id) does not denote a type.
+
+ In particular, this means that if an import prefix is shadowed by a local
+ declaration, it is an error to try to use it as a prefix for a type name.
+ PRIVATE_COLLISION_IN_MIXIN_APPLICATION:
+ template: "The private name '{0}', defined by '{1}', conflicts with the same name defined by '{2}'."
+ tip: "Try removing '{1}' from the 'with' clause."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the private name that collides
+ 1: the name of the first mixin
+ 2: the name of the second mixin
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when two mixins that define the same
+ private member are used together in a single class in a library other than
+ the one that defines the mixins.
+
+ #### Example
+
+ Given a file named `a.dart` containing the following code:
+
+ ```dart
+ %uri="lib/a.dart"
+ class A {
+ void _foo() {}
+ }
+
+ class B {
+ void _foo() {}
+ }
+ ```
+
+ The following code produces this diagnostic because the classes `A` and `B`
+ both define the method `_foo`:
+
+ ```dart
+ import 'a.dart';
+
+ class C extends Object with A, [!B!] {}
+ ```
+
+ #### Common fixes
+
+ If you don't need both of the mixins, then remove one of them from the
+ `with` clause:
+
+ ```dart
+ import 'a.dart';
+
+ class C extends Object with A, [!B!] {}
+ ```
+
+ If you need both of the mixins, then rename the conflicting member in one
+ of the two mixins.
+ PRIVATE_OPTIONAL_PARAMETER:
+ template: "Named parameters can't start with an underscore."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name of a named parameter
+ starts with an underscore.
+
+ #### Example
+
+ The following code produces this diagnostic because the named parameter
+ `_x` starts with an underscore:
+
+ ```dart
+ class C {
+ void m({int [!_x!] = 0}) {}
+ }
+ ```
+
+ #### Common fixes
+
+ Rename the parameter so that it doesn't start with an underscore:
+
+ ```dart
+ class C {
+ void m({int x = 0}) {}
+ }
+ ```
+ PRIVATE_SETTER:
+ template: "The setter '{0}' is private and can't be accessed outside of the library that declares it."
+ tip: Try making it public.
+ READ_POTENTIALLY_UNASSIGNED_FINAL:
+ template: "The final variable '{0}' can't be read because it is potentially unassigned at this point."
+ tip: Ensure that it is assigned on necessary execution paths.
+ RECURSIVE_COMPILE_TIME_CONSTANT:
+ template: The compile-time constant expression depends on itself.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the value of a compile-time
+ constant is defined in terms of itself, either directly or indirectly,
+ creating an infinite loop.
+
+ #### Example
+
+ The following code produces this diagnostic twice because both of the
+ constants are defined in terms of the other:
+
+ ```dart
+ const [!secondsPerHour!] = minutesPerHour * 60;
+ const [!minutesPerHour!] = secondsPerHour / 60;
+ ```
+
+ #### Common fixes
+
+ Break the cycle by finding an alternative way of defining at least one of
+ the constants:
+
+ ```dart
+ const secondsPerHour = minutesPerHour * 60;
+ const minutesPerHour = 60;
+ ```
+ RECURSIVE_CONSTRUCTOR_REDIRECT:
+ template: "Constructors can't redirect to themselves either directly or indirectly."
+ tip: Try changing one of the constructors in the loop to not redirect.
+ hasPublishedDocs: true
+ comment: |-
+ No parameters.
+
+ TODO(scheglov) review this later, there are no explicit "it is a
+ compile-time error" in specification. But it was added to the co19 and
+ there is same error for factories.
+
+ https://code.google.com/p/dart/issues/detail?id=954
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor redirects to
+ itself, either directly or indirectly, creating an infinite loop.
+
+ #### Example
+
+ The following code produces this diagnostic because the generative
+ constructors `C.a` and `C.b` each redirect to the other:
+
+ ```dart
+ class C {
+ C.a() : [!this.b()!];
+ C.b() : [!this.a()!];
+ }
+ ```
+
+ The following code produces this diagnostic because the factory
+ constructors `A` and `B` each redirect to the other:
+
+ ```dart
+ abstract class A {
+ factory A() = [!B!];
+ }
+ class B implements A {
+ factory B() = [!A!];
+ B.named();
+ }
+ ```
+
+ #### Common fixes
+
+ In the case of generative constructors, break the cycle by finding defining
+ at least one of the constructors to not redirect to another constructor:
+
+ ```dart
+ class C {
+ C.a() : this.b();
+ C.b();
+ }
+ ```
+
+ In the case of factory constructors, break the cycle by defining at least
+ one of the factory constructors to do one of the following:
+
+ - Redirect to a generative constructor:
+
+ ```dart
+ abstract class A {
+ factory A() = B;
+ }
+ class B implements A {
+ factory B() = B.named;
+ B.named();
+ }
+ ```
+
+ - Not redirect to another constructor:
+
+ ```dart
+ abstract class A {
+ factory A() = B;
+ }
+ class B implements A {
+ factory B() {
+ return B.named();
+ }
+
+ B.named();
+ }
+ ```
+
+ - Not be a factory constructor:
+
+ ```dart
+ abstract class A {
+ factory A() = B;
+ }
+ class B implements A {
+ B();
+ B.named();
+ }
+ ```
+ RECURSIVE_FACTORY_REDIRECT:
+ sharedName: RECURSIVE_CONSTRUCTOR_REDIRECT
+ template: "Constructors can't redirect to themselves either directly or indirectly."
+ tip: Try changing one of the constructors in the loop to not redirect.
+ hasPublishedDocs: true
+ comment: No parameters.
+ RECURSIVE_INTERFACE_INHERITANCE:
+ template: "'{0}' can't be a superinterface of itself: {1}."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the class that implements itself recursively
+ 1: a string representation of the implements loop
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when there's a circularity in the
+ type hierarchy. This happens when a type, either directly or indirectly,
+ is declared to be a subtype of itself.
+
+ #### Example
+
+ The following code produces this diagnostic because the class `A` is
+ declared to be a subtype of `B`, and `B` is a subtype of `A`:
+
+ ```dart
+ class [!A!] extends B {}
+ class B implements A {}
+ ```
+
+ #### Common fixes
+
+ Change the type hierarchy so that there's no circularity.
+ RECURSIVE_INTERFACE_INHERITANCE_EXTENDS:
+ sharedName: RECURSIVE_INTERFACE_INHERITANCE
+ template: "'{0}' can't extend itself."
+ hasPublishedDocs: true
+ comment: |-
+ 7.10 Superinterfaces: It is a compile-time error if the interface of a
+ class <i>C</i> is a superinterface of itself.
+
+ 8.1 Superinterfaces: It is a compile-time error if an interface is a
+ superinterface of itself.
+
+ 7.9 Superclasses: It is a compile-time error if a class <i>C</i> is a
+ superclass of itself.
+
+ Parameters:
+ 0: the name of the class that implements itself recursively
+ RECURSIVE_INTERFACE_INHERITANCE_IMPLEMENTS:
+ sharedName: RECURSIVE_INTERFACE_INHERITANCE
+ template: "'{0}' can't implement itself."
+ hasPublishedDocs: true
+ comment: |-
+ 7.10 Superinterfaces: It is a compile-time error if the interface of a
+ class <i>C</i> is a superinterface of itself.
+
+ 8.1 Superinterfaces: It is a compile-time error if an interface is a
+ superinterface of itself.
+
+ 7.9 Superclasses: It is a compile-time error if a class <i>C</i> is a
+ superclass of itself.
+
+ Parameters:
+ 0: the name of the class that implements itself recursively
+ RECURSIVE_INTERFACE_INHERITANCE_ON:
+ sharedName: RECURSIVE_INTERFACE_INHERITANCE
+ template: "'{0}' can't use itself as a superclass constraint."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the mixin that constraints itself recursively
+ RECURSIVE_INTERFACE_INHERITANCE_WITH:
+ sharedName: RECURSIVE_INTERFACE_INHERITANCE
+ template: "'{0}' can't use itself as a mixin."
+ hasPublishedDocs: true
+ comment: |-
+ 7.10 Superinterfaces: It is a compile-time error if the interface of a
+ class <i>C</i> is a superinterface of itself.
+
+ 8.1 Superinterfaces: It is a compile-time error if an interface is a
+ superinterface of itself.
+
+ 7.9 Superclasses: It is a compile-time error if a class <i>C</i> is a
+ superclass of itself.
+
+ Parameters:
+ 0: the name of the class that implements itself recursively
+ REDIRECT_GENERATIVE_TO_MISSING_CONSTRUCTOR:
+ template: "The constructor '{0}' couldn't be found in '{1}'."
+ tip: "Try redirecting to a different constructor, or defining the constructor named '{0}'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a generative constructor
+ redirects to a constructor that isn't defined.
+
+ #### Example
+
+ The following code produces this diagnostic because the constructor `C.a`
+ redirects to the constructor `C.b`, but `C.b` isn't defined:
+
+ ```dart
+ class C {
+ C.a() : [!this.b()!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the missing constructor must be called, then define it:
+
+ ```dart
+ class C {
+ C.a() : this.b();
+ C.b();
+ }
+ ```
+
+ If the missing constructor doesn't need to be called, then remove the
+ redirect:
+
+ ```dart
+ class C {
+ C.a();
+ }
+ ```
+ REDIRECT_GENERATIVE_TO_NON_GENERATIVE_CONSTRUCTOR:
+ template: "Generative constructors can't redirect to a factory constructor."
+ tip: Try redirecting to a different constructor.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a generative constructor
+ redirects to a factory constructor.
+
+ #### Example
+
+ The following code produces this diagnostic because the generative
+ constructor `C.a` redirects to the factory constructor `C.b`:
+
+ ```dart
+ class C {
+ C.a() : [!this.b()!];
+ factory C.b() => C.a();
+ }
+ ```
+
+ #### Common fixes
+
+ If the generative constructor doesn't need to redirect to another
+ constructor, then remove the redirect.
+
+ ```dart
+ class C {
+ C.a();
+ factory C.b() => C.a();
+ }
+ ```
+
+ If the generative constructor must redirect to another constructor, then
+ make the other constructor be a generative (non-factory) constructor:
+
+ ```dart
+ class C {
+ C.a() : this.b();
+ C.b();
+ }
+ ```
+ REDIRECT_TO_ABSTRACT_CLASS_CONSTRUCTOR:
+ template: "The redirecting constructor '{0}' can't redirect to a constructor of the abstract class '{1}'."
+ tip: Try redirecting to a constructor of a different class.
+ comment: |-
+ A factory constructor can't redirect to a non-generative constructor of an
+ abstract class.
+ REDIRECT_TO_INVALID_FUNCTION_TYPE:
+ template: "The redirected constructor '{0}' has incompatible parameters with '{1}'."
+ tip: Try redirecting to a different constructor.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the redirected constructor
+ 1: the name of the redirecting constructor
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a factory constructor attempts
+ to redirect to another constructor, but the two have incompatible
+ parameters. The parameters are compatible if all of the parameters of the
+ redirecting constructor can be passed to the other constructor and if the
+ other constructor doesn't require any parameters that aren't declared by
+ the redirecting constructor.
+
+ #### Examples
+
+ The following code produces this diagnostic because the constructor for `A`
+ doesn't declare a parameter that the constructor for `B` requires:
+
+ ```dart
+ abstract class A {
+ factory A() = [!B!];
+ }
+
+ class B implements A {
+ B(int x);
+ B.zero();
+ }
+ ```
+
+ The following code produces this diagnostic because the constructor for `A`
+ declares a named parameter (`y`) that the constructor for `B` doesn't
+ allow:
+
+ ```dart
+ abstract class A {
+ factory A(int x, {int y}) = [!B!];
+ }
+
+ class B implements A {
+ B(int x);
+ }
+ ```
+
+ #### Common fixes
+
+ If there's a different constructor that is compatible with the redirecting
+ constructor, then redirect to that constructor:
+
+ ```dart
+ abstract class A {
+ factory A() = B.zero;
+ }
+
+ class B implements A {
+ B(int x);
+ B.zero();
+ }
+ ```
+
+ Otherwise, update the redirecting constructor to be compatible:
+
+ ```dart
+ abstract class A {
+ factory A(int x) = B;
+ }
+
+ class B implements A {
+ B(int x);
+ }
+ ```
+ REDIRECT_TO_INVALID_RETURN_TYPE:
+ template: "The return type '{0}' of the redirected constructor isn't a subtype of '{1}'."
+ tip: Try redirecting to a different constructor.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the redirected constructor's return type
+ 1: the name of the redirecting constructor's return type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a factory constructor redirects
+ to a constructor whose return type isn't a subtype of the type that the
+ factory constructor is declared to produce.
+
+ #### Examples
+
+ The following code produces this diagnostic because `A` isn't a subclass
+ of `C`, which means that the value returned by the constructor `A()`
+ couldn't be returned from the constructor `C()`:
+
+ ```dart
+ class A {}
+
+ class B implements C {}
+
+ class C {
+ factory C() = [!A!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the factory constructor is redirecting to a constructor in the wrong
+ class, then update the factory constructor to redirect to the correct
+ constructor:
+
+ ```dart
+ class A {}
+
+ class B implements C {}
+
+ class C {
+ factory C() = B;
+ }
+ ```
+
+ If the class defining the constructor being redirected to is the class that
+ should be returned, then make it a subtype of the factory's return type:
+
+ ```dart
+ class A implements C {}
+
+ class B implements C {}
+
+ class C {
+ factory C() = A;
+ }
+ ```
+ REDIRECT_TO_MISSING_CONSTRUCTOR:
+ template: "The constructor '{0}' couldn't be found in '{1}'."
+ tip: "Try redirecting to a different constructor, or define the constructor named '{0}'."
+ comment: |-
+ 7.6.2 Factories: It is a compile-time error if <i>k</i> is prefixed with
+ the const modifier but <i>k'</i> is not a constant constructor.
+ REDIRECT_TO_NON_CLASS:
+ template: "The name '{0}' isn't a type and can't be used in a redirected constructor."
+ tip: Try redirecting to a different constructor.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the non-type referenced in the redirect
+ documentation: |-
+ #### Description
+
+ One way to implement a factory constructor is to redirect to another
+ constructor by referencing the name of the constructor. The analyzer
+ produces this diagnostic when the redirect is to something other than a
+ constructor.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` is a function:
+
+ ```dart
+ C f() => throw 0;
+
+ class C {
+ factory C() = [!f!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the constructor isn't defined, then either define it or replace it with
+ a constructor that is defined.
+
+ If the constructor is defined but the class that defines it isn't visible,
+ then you probably need to add an import.
+
+ If you're trying to return the value returned by a function, then rewrite
+ the constructor to return the value from the constructor's body:
+
+ ```dart
+ C f() => throw 0;
+
+ class C {
+ factory C() => f();
+ }
+ ```
+ REDIRECT_TO_NON_CONST_CONSTRUCTOR:
+ template: "A constant redirecting constructor can't redirect to a non-constant constructor."
+ tip: Try redirecting to a different constructor.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor marked as `const`
+ redirects to a constructor that isn't marked as `const`.
+
+ #### Example
+
+ The following code produces this diagnostic because the constructor `C.a`
+ is marked as `const` but redirects to the constructor `C.b`, which isn't:
+
+ ```dart
+ class C {
+ const C.a() : this.[!b!]();
+ C.b();
+ }
+ ```
+
+ #### Common fixes
+
+ If the non-constant constructor can be marked as `const`, then mark it as
+ `const`:
+
+ ```dart
+ class C {
+ const C.a() : this.b();
+ const C.b();
+ }
+ ```
+
+ If the non-constant constructor can't be marked as `const`, then either
+ remove the redirect or remove `const` from the redirecting constructor:
+
+ ```dart
+ class C {
+ C.a() : this.b();
+ C.b();
+ }
+ ```
+ REDIRECT_TO_TYPE_ALIAS_EXPANDS_TO_TYPE_PARAMETER:
+ template: "A redirecting constructor can't redirect to a type alias that expands to a type parameter."
+ tip: Try replacing it with a class.
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a redirecting factory
+ constructor redirects to a type alias, and the type alias expands to one of
+ the type parameters of the type alias. This isn’t allowed because the value
+ of the type parameter is a type rather than a class.
+
+ #### Example
+
+ The following code produces this diagnostic because the redirect to `B<A>`
+ is to a type alias whose value is `T`, even though it looks like the value
+ should be `A`:
+
+ ```dart
+ class A implements C {}
+
+ typedef B<T> = T;
+
+ abstract class C {
+ factory C() = [!B!]<A>;
+ }
+ ```
+
+ #### Common fixes
+
+ Use either a class name or a type alias that is defined to be a class
+ rather than a type alias defined to be a type parameter:
+
+ ```dart
+ class A implements C {}
+
+ abstract class C {
+ factory C() = A;
+ }
+ ```
+ REFERENCED_BEFORE_DECLARATION:
+ template: "Local variable '{0}' can't be referenced before it is declared."
+ tip: "Try moving the declaration to before the first use, or renaming the local variable so that it doesn't hide a name from an enclosing scope."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a variable is referenced before
+ it’s declared. In Dart, variables are visible everywhere in the block in
+ which they are declared, but can only be referenced after they are
+ declared.
+
+ The analyzer also produces a context message that indicates where the
+ declaration is located.
+
+ #### Examples
+
+ The following code produces this diagnostic because `i` is used before it
+ is declared:
+
+ ```dart
+ %language=2.9
+ void f() {
+ print([!i!]);
+ int i = 5;
+ }
+ ```
+
+ #### Common fixes
+
+ If you intended to reference the local variable, move the declaration
+ before the first reference:
+
+ ```dart
+ %language=2.9
+ void f() {
+ int i = 5;
+ print(i);
+ }
+ ```
+
+ If you intended to reference a name from an outer scope, such as a
+ parameter, instance field or top-level variable, then rename the local
+ declaration so that it doesn't hide the outer variable.
+
+ ```dart
+ %language=2.9
+ void f(int i) {
+ print(i);
+ int x = 5;
+ print(x);
+ }
+ ```
+ RETHROW_OUTSIDE_CATCH:
+ template: A rethrow must be inside of a catch clause.
+ tip: "Try moving the expression into a catch clause, or using a 'throw' expression."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `rethrow` statement is outside
+ a `catch` clause. The `rethrow` statement is used to throw a caught
+ exception again, but there's no caught exception outside of a `catch`
+ clause.
+
+ #### Example
+
+ The following code produces this diagnostic because the`rethrow` statement
+ is outside of a `catch` clause:
+
+ ```dart
+ void f() {
+ [!rethrow!];
+ }
+ ```
+
+ #### Common fixes
+
+ If you're trying to rethrow an exception, then wrap the `rethrow` statement
+ in a `catch` clause:
+
+ ```dart
+ void f() {
+ try {
+ // ...
+ } catch (exception) {
+ rethrow;
+ }
+ }
+ ```
+
+ If you're trying to throw a new exception, then replace the `rethrow`
+ statement with a `throw` expression:
+
+ ```dart
+ void f() {
+ throw UnsupportedError('Not yet implemented');
+ }
+ ```
+ RETURN_IN_GENERATIVE_CONSTRUCTOR:
+ template: "Constructors can't return values."
+ tip: Try removing the return statement or using a factory constructor.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a generative constructor
+ contains a `return` statement that specifies a value to be returned.
+ Generative constructors always return the object that was created, and
+ therefore can't return a different object.
+
+ #### Example
+
+ The following code produces this diagnostic because the `return` statement
+ has an expression:
+
+ ```dart
+ class C {
+ C() {
+ return [!this!];
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the constructor should create a new instance, then remove either the
+ `return` statement or the expression:
+
+ ```dart
+ class C {
+ C();
+ }
+ ```
+
+ If the constructor shouldn't create a new instance, then convert it to be a
+ factory constructor:
+
+ ```dart
+ class C {
+ factory C() {
+ return _instance;
+ }
+
+ static C _instance = C._();
+
+ C._();
+ }
+ ```
+ RETURN_IN_GENERATOR:
+ template: "Can't return a value from a generator function that uses the 'async*' or 'sync*' modifier."
+ tip: "Try replacing 'return' with 'yield', using a block function body, or changing the method body modifier."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a generator function (one whose
+ body is marked with either `async*` or `sync*`) uses either a `return`
+ statement to return a value or implicitly returns a value because of using
+ `=>`. In any of these cases, they should use `yield` instead of `return`.
+
+ #### Example
+
+ The following code produces this diagnostic because the method `f` is a
+ generator and is using `return` to return a value:
+
+ ```dart
+ Iterable<int> f() sync* {
+ [!return 3!];
+ }
+ ```
+
+ The following code produces this diagnostic because the function `f` is a
+ generator and is implicitly returning a value:
+
+ ```dart
+ Stream<int> f() async* [!=>!] 3;
+ ```
+
+ #### Common fixes
+
+ If the function is using `=>` for the body of the function, then convert it
+ to a block function body, and use `yield` to return a value:
+
+ ```dart
+ Stream<int> f() async* {
+ yield 3;
+ }
+ ```
+
+ If the method is intended to be a generator, then use `yield` to return a
+ value:
+
+ ```dart
+ Iterable<int> f() sync* {
+ yield 3;
+ }
+ ```
+
+ If the method isn't intended to be a generator, then remove the modifier
+ from the body (or use `async` if you're returning a future):
+
+ ```dart
+ int f() {
+ return 3;
+ }
+ ```
+ RETURN_OF_INVALID_TYPE_FROM_CONSTRUCTOR:
+ sharedName: RETURN_OF_INVALID_TYPE
+ template: "A value of type '{0}' can't be returned from the constructor '{2}' because it has a return type of '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the return type as declared in the return statement
+ 1: the expected return type as defined by the enclosing class
+ 2: the name of the constructor
+ RETURN_OF_INVALID_TYPE_FROM_FUNCTION:
+ sharedName: RETURN_OF_INVALID_TYPE
+ template: "A value of type '{0}' can't be returned from the function '{2}' because it has a return type of '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the return type as declared in the return statement
+ 1: the expected return type as defined by the method
+ 2: the name of the method
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function returns a
+ value whose type isn't assignable to the declared return type.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` has a return type
+ of `String` but is returning an `int`:
+
+ ```dart
+ String f() => [!3!];
+ ```
+
+ #### Common fixes
+
+ If the return type is correct, then replace the value being returned with a
+ value of the correct type, possibly by converting the existing value:
+
+ ```dart
+ String f() => 3.toString();
+ ```
+
+ If the value is correct, then change the return type to match:
+
+ ```dart
+ int f() => 3;
+ ```
+ RETURN_OF_INVALID_TYPE_FROM_METHOD:
+ sharedName: RETURN_OF_INVALID_TYPE
+ template: "A value of type '{0}' can't be returned from the method '{2}' because it has a return type of '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the return type as declared in the return statement
+ 1: the expected return type as defined by the method
+ 2: the name of the method
+ RETURN_OF_INVALID_TYPE_FROM_CLOSURE:
+ template: "The return type '{0}' isn't a '{1}', as required by the closure's context."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the return type as declared in the return statement
+ 1: the expected return type as defined by the method
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the static type of a returned
+ expression isn't assignable to the return type that the closure is required
+ to have.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` is defined to be a
+ function that returns a `String`, but the closure assigned to it returns an
+ `int`:
+
+ ```dart
+ String Function(String) f = (s) => [!3!];
+ ```
+
+ #### Common fixes
+
+ If the return type is correct, then replace the returned value with a value
+ of the correct type, possibly by converting the existing value:
+
+ ```dart
+ String Function(String) f = (s) => 3.toString();
+ ```
+ RETURN_WITHOUT_VALUE:
+ template: "The return value is missing after 'return'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds a `return` statement
+ without an expression in a function that declares a return type.
+
+ #### Examples
+
+ The following code produces this diagnostic because the function `f` is
+ expected to return an `int`, but no value is being returned:
+
+ ```dart
+ int f() {
+ [!return!];
+ }
+ ```
+
+ #### Common fixes
+
+ Add an expression that computes the value to be returned:
+
+ ```dart
+ int f() {
+ return 0;
+ }
+ ```
+ SET_ELEMENT_TYPE_NOT_ASSIGNABLE:
+ template: "The element type '{0}' can't be assigned to the set type '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the actual type of the set element
+ 1: the expected type of the set element
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an element in a set literal has
+ a type that isn't assignable to the element type of the set.
+
+ #### Example
+
+ The following code produces this diagnostic because the type of the string
+ literal `'0'` is `String`, which isn't assignable to `int`, the element
+ type of the set:
+
+ ```dart
+ var s = <int>{[!'0'!]};
+ ```
+
+ #### Common fixes
+
+ If the element type of the set literal is wrong, then change the element
+ type of the set:
+
+ ```dart
+ var s = <String>{'0'};
+ ```
+
+ If the type of the element is wrong, then change the element:
+
+ ```dart
+ var s = <int>{'0'.length};
+ ```
+ SHARED_DEFERRED_PREFIX:
+ template: "The prefix of a deferred import can't be used in other import directives."
+ tip: Try renaming one of the prefixes.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a prefix in a deferred import is
+ also used as a prefix in other imports (whether deferred or not). The
+ prefix in a deferred import can't be shared with other imports because the
+ prefix is used to load the imported library.
+
+ #### Example
+
+ The following code produces this diagnostic because the prefix `x` is used
+ as the prefix for a deferred import and is also used for one other import:
+
+ ```dart
+ import 'dart:math' [!deferred!] as x;
+ import 'dart:convert' as x;
+
+ var y = x.json.encode(x.min(0, 1));
+ ```
+
+ #### Common fixes
+
+ If you can use a different name for the deferred import, then do so:
+
+ ```dart
+ import 'dart:math' deferred as math;
+ import 'dart:convert' as x;
+
+ var y = x.json.encode(math.min(0, 1));
+ ```
+
+ If you can use a different name for the other imports, then do so:
+
+ ```dart
+ import 'dart:math' deferred as x;
+ import 'dart:convert' as convert;
+
+ var y = convert.json.encode(x.min(0, 1));
+ ```
+ SPREAD_EXPRESSION_FROM_DEFERRED_LIBRARY:
+ template: "Constant values from a deferred library can't be spread into a const literal."
+ tip: Try making the deferred import non-deferred.
+ STATIC_ACCESS_TO_INSTANCE_MEMBER:
+ template: "Instance member '{0}' can't be accessed using static access."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the instance member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class name is used to access
+ an instance field. Instance fields don't exist on a class; they exist only
+ on an instance of the class.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` is an instance
+ field:
+
+ ```dart
+ %language=2.9
+ class C {
+ static int a;
+
+ int b;
+ }
+
+ int f() => C.[!b!];
+ ```
+
+ #### Common fixes
+
+ If you intend to access a static field, then change the name of the field
+ to an existing static field:
+
+ ```dart
+ %language=2.9
+ class C {
+ static int a;
+
+ int b;
+ }
+
+ int f() => C.a;
+ ```
+
+ If you intend to access the instance field, then use an instance of the
+ class to access the field:
+
+ ```dart
+ %language=2.9
+ class C {
+ static int a;
+
+ int b;
+ }
+
+ int f(C c) => c.b;
+ ```
+ IMPLEMENTS_DEFERRED_CLASS:
+ sharedName: SUBTYPE_OF_DEFERRED_CLASS
+ template: "Classes and mixins can't implement deferred classes."
+ tip: Try specifying a different interface, removing the class from the list, or changing the import to not be deferred.
+ hasPublishedDocs: true
+ comment: No parameters.
+ MIXIN_DEFERRED_CLASS:
+ sharedName: SUBTYPE_OF_DEFERRED_CLASS
+ template: "Classes can't mixin deferred classes."
+ tip: Try changing the import to not be deferred.
+ hasPublishedDocs: true
+ comment: No parameters.
+ EXTENDS_DEFERRED_CLASS:
+ sharedName: SUBTYPE_OF_DEFERRED_CLASS
+ template: "Classes can't extend deferred classes."
+ tip: Try specifying a different superclass, or removing the extends clause.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a type (class or mixin) is a
+ subtype of a class from a library being imported using a deferred import.
+ The supertypes of a type must be compiled at the same time as the type, and
+ classes from deferred libraries aren't compiled until the library is
+ loaded.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ Given a file (`a.dart`) that defines the class `A`:
+
+ ```dart
+ %uri="lib/a.dart"
+ class A {}
+ ```
+
+ The following code produces this diagnostic because the superclass of `B`
+ is declared in a deferred library:
+
+ ```dart
+ import 'a.dart' deferred as a;
+
+ class B extends [!a.A!] {}
+ ```
+
+ #### Common fixes
+
+ If you need to create a subtype of a type from the deferred library, then
+ remove the `deferred` keyword:
+
+ ```dart
+ import 'a.dart' as a;
+
+ class B extends a.A {}
+ ```
+ EXTENDS_DISALLOWED_CLASS:
+ sharedName: SUBTYPE_OF_DISALLOWED_TYPE
+ template: "Classes can't extend '{0}'."
+ tip: Try specifying a different superclass, or removing the extends clause.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the disallowed type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when one of the restricted classes is
+ used in either an `extends`, `implements`, `with`, or `on` clause. The
+ classes `bool`, `double`, `FutureOr`, `int`, `Null`, `num`, and `String`
+ are all restricted in this way, to allow for more efficient
+ implementations.
+
+ #### Example
+
+ The following code produces this diagnostic because `String` is used in an
+ `extends` clause:
+
+ ```dart
+ class A extends [!String!] {}
+ ```
+
+ The following code produces this diagnostic because `String` is used in an
+ `implements` clause:
+
+ ```dart
+ class B implements [!String!] {}
+ ```
+
+ The following code produces this diagnostic because `String` is used in a
+ `with` clause:
+
+ ```dart
+ class C with [!String!] {}
+ ```
+
+ The following code produces this diagnostic because `String` is used in an
+ `on` clause:
+
+ ```dart
+ mixin M on [!String!] {}
+ ```
+
+ #### Common fixes
+
+ If a different type should be specified, then replace the type:
+
+ ```dart
+ class A extends Object {}
+ ```
+
+ If there isn't a different type that would be appropriate, then remove the
+ type, and possibly the whole clause:
+
+ ```dart
+ class B {}
+ ```
+ MIXIN_OF_DISALLOWED_CLASS:
+ sharedName: SUBTYPE_OF_DISALLOWED_TYPE
+ template: "Classes can't mixin '{0}'."
+ tip: Try specifying a different class or mixin, or remove the class or mixin from the list.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the disallowed type
+ MIXIN_SUPER_CLASS_CONSTRAINT_DISALLOWED_CLASS:
+ sharedName: SUBTYPE_OF_DISALLOWED_TYPE
+ template: "''{0}' can't be used as a superclass constraint."
+ tip: "Try specifying a different super-class constraint, or remove the 'on' clause."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the disallowed type
+ IMPLEMENTS_DISALLOWED_CLASS:
+ sharedName: SUBTYPE_OF_DISALLOWED_TYPE
+ template: "Classes and mixins can't implement '{0}'."
+ tip: Try specifying a different interface, or remove the class from the list.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the disallowed type
+ EXTENDS_TYPE_ALIAS_EXPANDS_TO_TYPE_PARAMETER:
+ sharedName: SUPERTYPE_EXPANDS_TO_TYPE_PARAMETER
+ template: "A type alias that expands to a type parameter can't be used as a superclass."
+ tip: Try specifying a different superclass, or removing the extends clause.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a type alias that expands to a
+ type parameter is used in an `extends`, `implements`, `with`, or `on`
+ clause.
+
+ #### Example
+
+ The following code produces this diagnostic because the type alias `T`,
+ which expands to the type parameter `S`, is used in the `extends` clause of
+ the class `C`:
+
+ ```dart
+ typedef T<S> = S;
+
+ class C extends [!T!]<Object> {}
+ ```
+
+ #### Common fixes
+
+ Use the value of the type argument directly:
+
+ ```dart
+ typedef T<S> = S;
+
+ class C extends Object {}
+ ```
+ MIXIN_ON_TYPE_ALIAS_EXPANDS_TO_TYPE_PARAMETER:
+ sharedName: SUPERTYPE_EXPANDS_TO_TYPE_PARAMETER
+ template: "A type alias that expands to a type parameter can't be used as a superclass constraint."
+ hasPublishedDocs: true
+ comment: No parameters.
+ MIXIN_OF_TYPE_ALIAS_EXPANDS_TO_TYPE_PARAMETER:
+ sharedName: SUPERTYPE_EXPANDS_TO_TYPE_PARAMETER
+ template: "A type alias that expands to a type parameter can't be mixed in."
+ hasPublishedDocs: true
+ comment: No parameters.
+ IMPLEMENTS_TYPE_ALIAS_EXPANDS_TO_TYPE_PARAMETER:
+ sharedName: SUPERTYPE_EXPANDS_TO_TYPE_PARAMETER
+ template: "A type alias that expands to a type parameter can't be implemented."
+ tip: Try specifying a class or mixin, or removing the list.
+ hasPublishedDocs: true
+ comment: No parameters.
+ SUPER_INITIALIZER_IN_OBJECT:
+ template: "The class 'Object' can't invoke a constructor from a superclass."
+ comment: |-
+ 7.6.1 Generative Constructors: Let <i>k</i> be a generative constructor. It
+ is a compile-time error if a generative constructor of class Object
+ includes a superinitializer.
+ SUPER_IN_EXTENSION:
+ template: "The 'super' keyword can't be used in an extension because an extension doesn't have a superclass."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a member declared inside an
+ extension uses the `super` keyword . Extensions aren't classes and don't
+ have superclasses, so the `super` keyword serves no purpose.
+
+ #### Examples
+
+ The following code produces this diagnostic because `super` can't be used
+ in an extension:
+
+ ```dart
+ extension E on Object {
+ String get displayString => [!super!].toString();
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the `super` keyword :
+
+ ```dart
+ extension E on Object {
+ String get displayString => toString();
+ }
+ ```
+ SUPER_IN_INVALID_CONTEXT:
+ template: "Invalid context for 'super' invocation."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the keyword `super` is used
+ outside of a instance method.
+
+ #### Examples
+
+ The following code produces this diagnostic because `super` is used in a
+ top-level function:
+
+ ```dart
+ void f() {
+ [!super!].f();
+ }
+ ```
+
+ #### Common fixes
+
+ Rewrite the code to not use `super`.
+ SUPER_IN_REDIRECTING_CONSTRUCTOR:
+ template: "The redirecting constructor can't have a 'super' initializer."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor that redirects to
+ another constructor also attempts to invoke a constructor from the
+ superclass. The superclass constructor will be invoked when the constructor
+ that the redirecting constructor is redirected to is invoked.
+
+ #### Example
+
+ The following code produces this diagnostic because the constructor `C.a`
+ both redirects to `C.b` and invokes a constructor from the superclass:
+
+ ```dart
+ class C {
+ C.a() : this.b(), [!super()!];
+ C.b();
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the invocation of the `super` constructor:
+
+ ```dart
+ class C {
+ C.a() : this.b();
+ C.b();
+ }
+ ```
+ SWITCH_CASE_COMPLETES_NORMALLY:
+ template: "The 'case' should not complete normally."
+ tip: "Try adding 'break', or 'return', etc."
+ comment: |-
+ It is an error if any case of a switch statement except the last case (the
+ default case if present) may complete normally. The previous syntactic
+ restriction requiring the last statement of each case to be one of an
+ enumerated list of statements (break, continue, return, throw, or rethrow)
+ is removed.
+ SWITCH_EXPRESSION_NOT_ASSIGNABLE:
+ template: "Type '{0}' of the switch expression isn't assignable to the type '{1}' of case expressions."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the static type of the switch expression
+ 1: the static type of the case expressions
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type of the expression in a
+ `switch` statement isn't assignable to the type of the expressions in the
+ `case` clauses.
+
+ #### Example
+
+ The following code produces this diagnostic because the type of `s`
+ (`String`) isn't assignable to the type of `0` (`int`):
+
+ ```dart
+ %language=2.9
+ void f(String s) {
+ switch ([!s!]) {
+ case 0:
+ break;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the type of the `case` expressions is correct, then change the
+ expression in the `switch` statement to have the correct type:
+
+ ```dart
+ %language=2.9
+ void f(String s) {
+ switch (int.parse(s)) {
+ case 0:
+ break;
+ }
+ }
+ ```
+
+ If the type of the `switch` expression is correct, then change the `case`
+ expressions to have the correct type:
+
+ ```dart
+ %language=2.9
+ void f(String s) {
+ switch (s) {
+ case '0':
+ break;
+ }
+ }
+ ```
+ TEAROFF_OF_GENERATIVE_CONSTRUCTOR_OF_ABSTRACT_CLASS:
+ template: "A generative constructor of an abstract class can't be torn off."
+ tip: Try tearing off a constructor of a concrete class, or a non-generative constructor.
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a generative constructor from an
+ abstract class is being torn off. This isn't allowed because it isn't valid
+ to create an instance of an abstract class, which means that there isn't
+ any valid use for the torn off constructor.
+
+ #### Example
+
+ The following code produces this diagnostic because the constructor `C.new`
+ is being torn off and the class `C` is an abstract class:
+
+ ```dart
+ abstract class C {
+ C();
+ }
+
+ void f() {
+ [!C.new!];
+ }
+ ```
+
+ #### Common fixes
+
+ Tear off the constructor of a concrete class.
+ THROW_OF_INVALID_TYPE:
+ template: "The type '{0}' of the thrown expression must be assignable to 'Object'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type that can't be thrown
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type of the expression in a
+ throw expression isn't assignable to `Object`. It isn't valid to throw
+ `null`, so it isn't valid to use an expression that might evaluate to
+ `null`.
+
+ #### Example
+
+ The following code produces this diagnostic because `s` might be `null`:
+
+ ```dart
+ void f(String? s) {
+ throw [!s!];
+ }
+ ```
+
+ #### Common fixes
+
+ Add an explicit null check to the expression:
+
+ ```dart
+ void f(String? s) {
+ throw s!;
+ }
+ ```
+ TOP_LEVEL_CYCLE:
+ template: "The type of '{0}' can't be inferred because it depends on itself through the cycle: {1}."
+ tip: Try adding an explicit type to one or more of the variables in the cycle in order to break the cycle.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the element whose type could not be inferred.
+ 1: The [TopLevelInferenceError]'s arguments that led to the cycle.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a top-level variable has no type
+ annotation and the variable's initializer refers to the variable, either
+ directly or indirectly.
+
+ #### Example
+
+ The following code produces this diagnostic because the variables `x` and
+ `y` are defined in terms of each other, and neither has an explicit type,
+ so the type of the other can't be inferred:
+
+ ```dart
+ var x = y;
+ var y = [!x!];
+ ```
+
+ #### Common fixes
+
+ If the two variables don't need to refer to each other, then break the
+ cycle:
+
+ ```dart
+ var x = 0;
+ var y = x;
+ ```
+
+ If the two variables need to refer to each other, then give at least one of
+ them an explicit type:
+
+ ```dart
+ int x = y;
+ var y = x;
+ ```
+
+ Note, however, that while this code doesn't produce any diagnostics, it
+ will produce a stack overflow at runtime unless at least one of the
+ variables is assigned a value that doesn't depend on the other variables
+ before any of the variables in the cycle are referenced.
+ TYPE_ALIAS_CANNOT_REFERENCE_ITSELF:
+ template: "Typedefs can't reference themselves directly or recursively via another typedef."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a typedef refers to itself,
+ either directly or indirectly.
+
+ #### Example
+
+ The following code produces this diagnostic because `F` depends on itself
+ indirectly through `G`:
+
+ ```dart
+ typedef [!F!] = void Function(G);
+ typedef G = void Function(F);
+ ```
+
+ #### Common fixes
+
+ Change one or more of the typedefs in the cycle so that none of them refer
+ to themselves:
+
+ ```dart
+ typedef F = void Function(G);
+ typedef G = void Function(int);
+ ```
+ TYPE_ANNOTATION_DEFERRED_CLASS:
+ template: "The deferred type '{0}' can't be used in a declaration, cast, or type test."
+ tip: Try using a different type, or changing the import to not be deferred.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type that is deferred and being used in a type
+ annotation
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type annotation is in a
+ variable declaration, or the type used in a cast (`as`) or type test (`is`)
+ is a type declared in a library that is imported using a deferred import.
+ These types are required to be available at compile time, but aren't.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ The following code produces this diagnostic because the type of the
+ parameter `f` is imported from a deferred library:
+
+ ```dart
+ import 'dart:io' deferred as io;
+
+ void f([!io.File!] f) {}
+ ```
+
+ #### Common fixes
+
+ If you need to reference the imported type, then remove the `deferred`
+ keyword:
+
+ ```dart
+ import 'dart:io' as io;
+
+ void f(io.File f) {}
+ ```
+
+ If the import is required to be deferred and there's another type that is
+ appropriate, then use that type in place of the type from the deferred
+ library.
+ TYPE_ARGUMENT_NOT_MATCHING_BOUNDS:
+ template: "'{0}' doesn't conform to the bound '{2}' of the type parameter '{1}'."
+ tip: "Try using a type that is or is a subclass of '{2}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type used in the instance creation that should be
+ limited by the bound as specified in the class declaration
+ 1: the name of the type parameter
+ 2: the substituted bound of the type parameter
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a type argument isn't the same
+ as or a subclass of the bounds of the corresponding type parameter.
+
+ #### Examples
+
+ The following code produces this diagnostic because `String` isn't a
+ subclass of `num`:
+
+ ```dart
+ class A<E extends num> {}
+
+ var a = A<[!String!]>();
+ ```
+
+ #### Common fixes
+
+ Change the type argument to be a subclass of the bounds:
+
+ ```dart
+ class A<E extends num> {}
+
+ var a = A<int>();
+ ```
+ TYPE_PARAMETER_REFERENCED_BY_STATIC:
+ template: "Static members can't reference type parameters of the class."
+ tip: Try removing the reference to the type parameter, or making the member an instance member.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a static member references a
+ type parameter that is declared for the class. Type parameters only have
+ meaning for instances of the class.
+
+ #### Example
+
+ The following code produces this diagnostic because the static method
+ `hasType` has a reference to the type parameter `T`:
+
+ ```dart
+ class C<T> {
+ static bool hasType(Object o) => o is [!T!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the member can be an instance member, then remove the keyword `static`:
+
+ ```dart
+ class C<T> {
+ bool hasType(Object o) => o is T;
+ }
+ ```
+
+ If the member must be a static member, then make the member be generic:
+
+ ```dart
+ class C<T> {
+ static bool hasType<S>(Object o) => o is S;
+ }
+ ```
+
+ Note, however, that there isn’t a relationship between `T` and `S`, so this
+ second option changes the semantics from what was likely to be intended.
+ TYPE_PARAMETER_SUPERTYPE_OF_ITS_BOUND:
+ template: "'{0}' can't be a supertype of its upper bound."
+ tip: "Try using a type that is the same as or a subclass of '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type parameter
+ 1: the name of the bounding type
+
+ See [CompileTimeErrorCode.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS].
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the bound of a type parameter
+ (the type following the `extends` keyword) is either directly or indirectly
+ the type parameter itself. Stating that the type parameter must be the same
+ as itself or a subtype of itself or a subtype of itself isn't helpful
+ because it will always be the same as itself.
+
+ #### Example
+
+ The following code produces this diagnostic because the bound of `T` is
+ `T`:
+
+ ```dart
+ class C<[!T!] extends T> {}
+ ```
+
+ The following code produces this diagnostic because the bound of `T1` is
+ `T2`, and the bound of `T2` is `T1`, effectively making the bound of `T1`
+ be `T1`:
+
+ ```dart
+ class C<[!T1!] extends T2, T2 extends T1> {}
+ ```
+
+ #### Common fixes
+
+ If the type parameter needs to be a subclass of some type, then replace the
+ bound with the required type:
+
+ ```dart
+ class C<T extends num> {}
+ ```
+
+ If the type parameter can be any type, then remove the `extends` clause:
+
+ ```dart
+ class C<T> {}
+ ```
+ TYPE_TEST_WITH_NON_TYPE:
+ template: "The name '{0}' isn't a type and can't be used in an 'is' expression."
+ tip: Try correcting the name to match an existing type.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the right-hand side of an `is`
+ or `is!` test isn't a type.
+
+ #### Example
+
+ The following code produces this diagnostic because the right-hand side is
+ a parameter, not a type:
+
+ ```dart
+ typedef B = int Function(int);
+
+ void f(Object a, B b) {
+ if (a is [!b!]) {
+ return;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If you intended to use a type test, then replace the right-hand side with a
+ type:
+
+ ```dart
+ typedef B = int Function(int);
+
+ void f(Object a, B b) {
+ if (a is B) {
+ return;
+ }
+ }
+ ```
+
+ If you intended to use a different kind of test, then change the test:
+
+ ```dart
+ typedef B = int Function(int);
+
+ void f(Object a, B b) {
+ if (a == b) {
+ return;
+ }
+ }
+ ```
+ TYPE_TEST_WITH_UNDEFINED_NAME:
+ template: "The name '{0}' isn't defined, so it can't be used in an 'is' expression."
+ tip: "Try changing the name to the name of an existing type, or creating a type with the name '{0}'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name following the `is` in a
+ type test expression isn't defined.
+
+ #### Examples
+
+ The following code produces this diagnostic because the name `Srting` isn't
+ defined:
+
+ ```dart
+ void f(Object o) {
+ if (o is [!Srting!]) {
+ // ...
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Replace the name with the name of a type:
+
+ ```dart
+ void f(Object o) {
+ if (o is String) {
+ // ...
+ }
+ }
+ ```
+ UNCHECKED_USE_OF_NULLABLE_VALUE_IN_SPREAD:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "A nullable expression can't be used in a spread."
+ tip: "Try checking that the value isn't 'null' before using it in a spread, or use a null-aware spread."
+ hasPublishedDocs: true
+ UNCHECKED_INVOCATION_OF_NULLABLE_VALUE:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "The function can't be unconditionally invoked because it can be 'null'."
+ tip: "Try adding a null check ('!')."
+ hasPublishedDocs: true
+ UNCHECKED_METHOD_INVOCATION_OF_NULLABLE_VALUE:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "The method '{0}' can't be unconditionally invoked because the receiver can be 'null'."
+ tip: "Try making the call conditional (using '?.') or adding a null check to the target ('!')."
+ hasPublishedDocs: true
+ UNCHECKED_OPERATOR_INVOCATION_OF_NULLABLE_VALUE:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "The operator '{0}' can't be unconditionally invoked because the receiver can be 'null'."
+ tip: "Try adding a null check to the target ('!')."
+ hasPublishedDocs: true
+ UNCHECKED_USE_OF_NULLABLE_VALUE_IN_YIELD_EACH:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "A nullable expression can't be used in a yield-each statement."
+ tip: "Try checking that the value isn't 'null' before using it in a yield-each statement."
+ hasPublishedDocs: true
+ UNCHECKED_USE_OF_NULLABLE_VALUE_AS_CONDITION:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "A nullable expression can't be used as a condition."
+ tip: "Try checking that the value isn't 'null' before using it as a condition."
+ hasPublishedDocs: true
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an expression whose type is
+ [potentially non-nullable][] is dereferenced without first verifying that
+ the value isn't `null`.
+
+ #### Example
+
+ The following code produces this diagnostic because `s` can be `null` at
+ the point where it's referenced:
+
+ ```dart
+ void f(String? s) {
+ if (s.[!length!] > 3) {
+ // ...
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the value really can be `null`, then add a test to ensure that members
+ are only accessed when the value isn't `null`:
+
+ ```dart
+ void f(String? s) {
+ if (s != null && s.length > 3) {
+ // ...
+ }
+ }
+ ```
+
+ If the expression is a variable and the value should never be `null`, then
+ change the type of the variable to be non-nullable:
+
+ ```dart
+ void f(String s) {
+ if (s.length > 3) {
+ // ...
+ }
+ }
+ ```
+
+ If you believe that the value of the expression should never be `null`, but
+ you can't change the type of the variable, and you're willing to risk
+ having an exception thrown at runtime if you're wrong, then you can assert
+ that the value isn't null:
+
+ ```dart
+ void f(String? s) {
+ if (s!.length > 3) {
+ // ...
+ }
+ }
+ ```
+ UNCHECKED_USE_OF_NULLABLE_VALUE_AS_ITERATOR:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "A nullable expression can't be used as an iterator in a for-in loop."
+ tip: "Try checking that the value isn't 'null' before using it as an iterator."
+ hasPublishedDocs: true
+ UNCHECKED_PROPERTY_ACCESS_OF_NULLABLE_VALUE:
+ sharedName: UNCHECKED_USE_OF_NULLABLE_VALUE
+ template: "The property '{0}' can't be unconditionally accessed because the receiver can be 'null'."
+ tip: "Try making the access conditional (using '?.') or adding a null check to the target ('!')."
+ hasPublishedDocs: true
+ UNDEFINED_ANNOTATION:
+ template: "Undefined name '{0}' used as an annotation."
+ tip: Try defining the name or importing it from another library.
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name that isn't defined is
+ used as an annotation.
+
+ #### Examples
+
+ The following code produces this diagnostic because the name `undefined`
+ isn't defined:
+
+ ```dart
+ [!@undefined!]
+ void f() {}
+ ```
+
+ #### Common fixes
+
+ If the name is correct, but it isn’t declared yet, then declare the name as
+ a constant value:
+
+ ```dart
+ const undefined = 'undefined';
+
+ @undefined
+ void f() {}
+ ```
+
+ If the name is wrong, replace the name with the name of a valid constant:
+
+ ```dart
+ @deprecated
+ void f() {}
+ ```
+
+ Otherwise, remove the annotation.
+ UNDEFINED_CLASS:
+ template: "Undefined class '{0}'."
+ tip: "Try changing the name to the name of an existing class, or creating a class with the name '{0}'."
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the undefined class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it encounters an identifier that
+ appears to be the name of a class but either isn't defined or isn't visible
+ in the scope in which it's being referenced.
+
+ #### Examples
+
+ The following code produces this diagnostic because `Piont` isn't defined:
+
+ ```dart
+ class Point {}
+
+ void f([!Piont!] p) {}
+ ```
+
+ #### Common fixes
+
+ If the identifier isn't defined, then either define it or replace it with
+ the name of a class that is defined. The example above can be corrected by
+ fixing the spelling of the class:
+
+ ```dart
+ class Point {}
+
+ void f(Point p) {}
+ ```
+
+ If the class is defined but isn't visible, then you probably need to add an
+ import.
+ UNDEFINED_CLASS_BOOLEAN:
+ sharedName: UNDEFINED_CLASS
+ template: "Undefined class '{0}'."
+ tip: "Try using the type 'bool'."
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Same as [CompileTimeErrorCode.UNDEFINED_CLASS], but to catch using
+ "boolean" instead of "bool" in order to improve the correction message.
+
+ Parameters:
+ 0: the name of the undefined class
+ UNDEFINED_CONSTRUCTOR_IN_INITIALIZER:
+ template: "The class '{0}' doesn't have a constructor named '{1}'."
+ tip: "Try defining a constructor named '{1}' in '{0}', or invoking a different constructor."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the superclass that does not define the invoked constructor
+ 1: the name of the constructor being invoked
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a superclass constructor is
+ invoked in the initializer list of a constructor, but the superclass
+ doesn't define the constructor being invoked.
+
+ #### Examples
+
+ The following code produces this diagnostic because `A` doesn't have an
+ unnamed constructor:
+
+ ```dart
+ class A {
+ A.n();
+ }
+ class B extends A {
+ B() : [!super()!];
+ }
+ ```
+
+ The following code produces this diagnostic because `A` doesn't have a
+ constructor named `m`:
+
+ ```dart
+ class A {
+ A.n();
+ }
+ class B extends A {
+ B() : [!super.m()!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the superclass defines a constructor that should be invoked, then change
+ the constructor being invoked:
+
+ ```dart
+ class A {
+ A.n();
+ }
+ class B extends A {
+ B() : super.n();
+ }
+ ```
+
+ If the superclass doesn't define an appropriate constructor, then define
+ the constructor being invoked:
+
+ ```dart
+ class A {
+ A.m();
+ A.n();
+ }
+ class B extends A {
+ B() : super.m();
+ }
+ ```
+ UNDEFINED_CONSTRUCTOR_IN_INITIALIZER_DEFAULT:
+ sharedName: UNDEFINED_CONSTRUCTOR_IN_INITIALIZER
+ template: "The class '{0}' doesn't have an unnamed constructor."
+ tip: "Try defining an unnamed constructor in '{0}', or invoking a different constructor."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the superclass that does not define the invoked constructor
+ UNDEFINED_ENUM_CONSTANT:
+ template: "There's no constant named '{0}' in '{1}'."
+ tip: "Try correcting the name to the name of an existing constant, or defining a constant named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the enumeration constant that is not defined
+ 1: the name of the enumeration used to access the constant
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it encounters an identifier that
+ appears to be the name of an enum constant, and the name either isn't
+ defined or isn't visible in the scope in which it's being referenced.
+
+ #### Examples
+
+ The following code produces this diagnostic because `E` doesn't define a
+ constant named `c`:
+
+ ```dart
+ enum E {a, b}
+
+ var e = E.[!c!];
+ ```
+
+ #### Common fixes
+
+ If the constant should be defined, then add it to the declaration of the
+ enum:
+
+ ```dart
+ enum E {a, b, c}
+
+ var e = E.c;
+ ```
+
+ If the constant shouldn't be defined, then change the name to the name of
+ an existing constant:
+
+ ```dart
+ enum E {a, b}
+
+ var e = E.b;
+ ```
+ UNDEFINED_EXTENSION_GETTER:
+ template: "The getter '{0}' isn't defined for the extension '{1}'."
+ tip: "Try correcting the name to the name of an existing getter, or defining a getter named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the getter that is undefined
+ 1: the name of the extension that was explicitly specified
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override is used to
+ invoke a getter, but the getter isn't defined by the specified extension.
+ The analyzer also produces this diagnostic when a static getter is
+ referenced but isn't defined by the specified extension.
+
+ #### Examples
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't declare an instance getter named `b`:
+
+ ```dart
+ extension E on String {
+ String get a => 'a';
+ }
+
+ extension F on String {
+ String get b => 'b';
+ }
+
+ void f() {
+ E('c').[!b!];
+ }
+ ```
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't declare a static getter named `a`:
+
+ ```dart
+ extension E on String {}
+
+ var x = E.[!a!];
+ ```
+
+ #### Common fixes
+
+ If the name of the getter is incorrect, then change it to the name of an
+ existing getter:
+
+ ```dart
+ extension E on String {
+ String get a => 'a';
+ }
+
+ extension F on String {
+ String get b => 'b';
+ }
+
+ void f() {
+ E('c').a;
+ }
+ ```
+
+ If the name of the getter is correct but the name of the extension is
+ wrong, then change the name of the extension to the correct name:
+
+ ```dart
+ extension E on String {
+ String get a => 'a';
+ }
+
+ extension F on String {
+ String get b => 'b';
+ }
+
+ void f() {
+ F('c').b;
+ }
+ ```
+
+ If the name of the getter and extension are both correct, but the getter
+ isn't defined, then define the getter:
+
+ ```dart
+ extension E on String {
+ String get a => 'a';
+ String get b => 'z';
+ }
+
+ extension F on String {
+ String get b => 'b';
+ }
+
+ void f() {
+ E('c').b;
+ }
+ ```
+ UNDEFINED_EXTENSION_METHOD:
+ template: "The method '{0}' isn't defined for the extension '{1}'."
+ tip: "Try correcting the name to the name of an existing method, or defining a method named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the method that is undefined
+ 1: the name of the extension that was explicitly specified
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override is used to
+ invoke a method, but the method isn't defined by the specified extension.
+ The analyzer also produces this diagnostic when a static method is
+ referenced but isn't defined by the specified extension.
+
+ #### Examples
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't declare an instance method named `b`:
+
+ ```dart
+ extension E on String {
+ String a() => 'a';
+ }
+
+ extension F on String {
+ String b() => 'b';
+ }
+
+ void f() {
+ E('c').[!b!]();
+ }
+ ```
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't declare a static method named `a`:
+
+ ```dart
+ extension E on String {}
+
+ var x = E.[!a!]();
+ ```
+
+ #### Common fixes
+
+ If the name of the method is incorrect, then change it to the name of an
+ existing method:
+
+ ```dart
+ extension E on String {
+ String a() => 'a';
+ }
+
+ extension F on String {
+ String b() => 'b';
+ }
+
+ void f() {
+ E('c').a();
+ }
+ ```
+
+ If the name of the method is correct, but the name of the extension is
+ wrong, then change the name of the extension to the correct name:
+
+ ```dart
+ extension E on String {
+ String a() => 'a';
+ }
+
+ extension F on String {
+ String b() => 'b';
+ }
+
+ void f() {
+ F('c').b();
+ }
+ ```
+
+ If the name of the method and extension are both correct, but the method
+ isn't defined, then define the method:
+
+ ```dart
+ extension E on String {
+ String a() => 'a';
+ String b() => 'z';
+ }
+
+ extension F on String {
+ String b() => 'b';
+ }
+
+ void f() {
+ E('c').b();
+ }
+ ```
+ UNDEFINED_EXTENSION_OPERATOR:
+ template: "The operator '{0}' isn't defined for the extension '{1}'."
+ tip: "Try defining the operator '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the operator that is undefined
+ 1: the name of the extension that was explicitly specified
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an operator is invoked on a
+ specific extension when that extension doesn't implement the operator.
+
+ #### Example
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't define the operator `*`:
+
+ ```dart
+ var x = E('') [!*!] 4;
+
+ extension E on String {}
+ ```
+
+ #### Common fixes
+
+ If the extension is expected to implement the operator, then add an
+ implementation of the operator to the extension:
+
+ ```dart
+ var x = E('') * 4;
+
+ extension E on String {
+ int operator *(int multiplier) => length * multiplier;
+ }
+ ```
+
+ If the operator is defined by a different extension, then change the name
+ of the extension to the name of the one that defines the operator.
+
+ If the operator is defined on the argument of the extension override, then
+ remove the extension override:
+
+ ```dart
+ var x = '' * 4;
+
+ extension E on String {}
+ ```
+ UNDEFINED_EXTENSION_SETTER:
+ template: "The setter '{0}' isn't defined for the extension '{1}'."
+ tip: "Try correcting the name to the name of an existing setter, or defining a setter named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the setter that is undefined
+ 1: the name of the extension that was explicitly specified
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension override is used to
+ invoke a setter, but the setter isn't defined by the specified extension.
+ The analyzer also produces this diagnostic when a static setter is
+ referenced but isn't defined by the specified extension.
+
+ #### Examples
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't declare an instance setter named `b`:
+
+ ```dart
+ extension E on String {
+ set a(String v) {}
+ }
+
+ extension F on String {
+ set b(String v) {}
+ }
+
+ void f() {
+ E('c').[!b!] = 'd';
+ }
+ ```
+
+ The following code produces this diagnostic because the extension `E`
+ doesn't declare a static setter named `a`:
+
+ ```dart
+ extension E on String {}
+
+ void f() {
+ E.[!a!] = 3;
+ }
+ ```
+
+ #### Common fixes
+
+ If the name of the setter is incorrect, then change it to the name of an
+ existing setter:
+
+ ```dart
+ extension E on String {
+ set a(String v) {}
+ }
+
+ extension F on String {
+ set b(String v) {}
+ }
+
+ void f() {
+ E('c').a = 'd';
+ }
+ ```
+
+ If the name of the setter is correct, but the name of the extension is
+ wrong, then change the name of the extension to the correct name:
+
+ ```dart
+ extension E on String {
+ set a(String v) {}
+ }
+
+ extension F on String {
+ set b(String v) {}
+ }
+
+ void f() {
+ F('c').b = 'd';
+ }
+ ```
+
+ If the name of the setter and extension are both correct, but the setter
+ isn't defined, then define the setter:
+
+ ```dart
+ extension E on String {
+ set a(String v) {}
+ set b(String v) {}
+ }
+
+ extension F on String {
+ set b(String v) {}
+ }
+
+ void f() {
+ E('c').b = 'd';
+ }
+ ```
+ UNDEFINED_FUNCTION:
+ template: "The function '{0}' isn't defined."
+ tip: "Try importing the library that defines '{0}', correcting the name to the name of an existing function, or defining a function named '{0}'."
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the method that is undefined
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it encounters an identifier that
+ appears to be the name of a function but either isn't defined or isn't
+ visible in the scope in which it's being referenced.
+
+ #### Examples
+
+ The following code produces this diagnostic because the name `emty` isn't
+ defined:
+
+ ```dart
+ List<int> empty() => [];
+
+ void main() {
+ print([!emty!]());
+ }
+ ```
+
+ #### Common fixes
+
+ If the identifier isn't defined, then either define it or replace it with
+ the name of a function that is defined. The example above can be corrected
+ by fixing the spelling of the function:
+
+ ```dart
+ List<int> empty() => [];
+
+ void main() {
+ print(empty());
+ }
+ ```
+
+ If the function is defined but isn't visible, then you probably need to add
+ an import or re-arrange your code to make the function visible.
+ UNDEFINED_GETTER:
+ template: "The getter '{0}' isn't defined for the type '{1}'."
+ tip: "Try importing the library that defines '{0}', correcting the name to the name of an existing getter, or defining a getter or field named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the getter
+ 1: the name of the enclosing type where the getter is being looked for
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it encounters an identifier that
+ appears to be the name of a getter but either isn't defined or isn't
+ visible in the scope in which it's being referenced.
+
+ #### Examples
+
+ The following code produces this diagnostic because `String` has no member
+ named `len`:
+
+ ```dart
+ int f(String s) => s.[!len!];
+ ```
+
+ #### Common fixes
+
+ If the identifier isn't defined, then either define it or replace it with
+ the name of a getter that is defined. The example above can be corrected by
+ fixing the spelling of the getter:
+
+ ```dart
+ int f(String s) => s.length;
+ ```
+ UNDEFINED_GETTER_ON_FUNCTION_TYPE:
+ sharedName: UNDEFINED_GETTER
+ template: "The getter '{0}' isn't defined for the '{1}' function type."
+ tip: "Try wrapping the function type alias in parentheses in order to access '{0}' as an extension getter on 'Type'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the getter
+ 1: the name of the function type alias
+ UNDEFINED_IDENTIFIER:
+ template: "Undefined name '{0}'."
+ tip: Try correcting the name to one that is defined, or defining the name.
+ isUnresolvedIdentifier: true
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the identifier
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it encounters an identifier that
+ either isn't defined or isn't visible in the scope in which it's being
+ referenced.
+
+ #### Examples
+
+ The following code produces this diagnostic because the name `rihgt` isn't
+ defined:
+
+ ```dart
+ int min(int left, int right) => left <= [!rihgt!] ? left : right;
+ ```
+
+ #### Common fixes
+
+ If the identifier isn't defined, then either define it or replace it with
+ an identifier that is defined. The example above can be corrected by
+ fixing the spelling of the variable:
+
+ ```dart
+ int min(int left, int right) => left <= right ? left : right;
+ ```
+
+ If the identifier is defined but isn't visible, then you probably need to
+ add an import or re-arrange your code to make the identifier visible.
+ UNDEFINED_IDENTIFIER_AWAIT:
+ template: "Undefined name 'await' in function body not marked with 'async'."
+ tip: "Try correcting the name to one that is defined, defining the name, or adding 'async' to the enclosing function body."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the name `await` is used in a
+ method or function body without being declared, and the body isn't marked
+ with the `async` keyword. The name `await` only introduces an await
+ expression in an asynchronous function.
+
+ #### Example
+
+ The following code produces this diagnostic because the name `await` is
+ used in the body of `f` even though the body of `f` isn't marked with the
+ `async` keyword:
+
+ ```dart
+ void f(p) { [!await!] p; }
+ ```
+
+ #### Common fixes
+
+ Add the keyword `async` to the function body:
+
+ ```dart
+ void f(p) async { await p; }
+ ```
+ UNDEFINED_METHOD:
+ template: "The method '{0}' isn't defined for the type '{1}'."
+ tip: "Try correcting the name to the name of an existing method, or defining a method named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the method that is undefined
+ 1: the resolved type name that the method lookup is happening on
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it encounters an identifier that
+ appears to be the name of a method but either isn't defined or isn't
+ visible in the scope in which it's being referenced.
+
+ #### Examples
+
+ The following code produces this diagnostic because the identifier
+ `removeMiddle` isn't defined:
+
+ ```dart
+ int f(List<int> l) => l.[!removeMiddle!]();
+ ```
+
+ #### Common fixes
+
+ If the identifier isn't defined, then either define it or replace it with
+ the name of a method that is defined. The example above can be corrected by
+ fixing the spelling of the method:
+
+ ```dart
+ int f(List<int> l) => l.removeLast();
+ ```
+ UNDEFINED_METHOD_ON_FUNCTION_TYPE:
+ sharedName: UNDEFINED_METHOD
+ template: "The method '{0}' isn't defined for the '{1}' function type."
+ tip: "Try wrapping the function type alias in parentheses in order to access '{0}' as an extension method on 'Type'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the method
+ 1: the name of the function type alias
+ UNDEFINED_NAMED_PARAMETER:
+ template: "The named parameter '{0}' isn't defined."
+ tip: "Try correcting the name to an existing named parameter's name, or defining a named parameter with the name '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the requested named parameter
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function invocation
+ has a named argument, but the method or function being invoked doesn't
+ define a parameter with the same name.
+
+ #### Examples
+
+ The following code produces this diagnostic because `m` doesn't declare a
+ named parameter named `a`:
+
+ ```dart
+ %language=2.9
+ class C {
+ m({int b}) {}
+ }
+
+ void f(C c) {
+ c.m([!a!]: 1);
+ }
+ ```
+
+ #### Common fixes
+
+ If the argument name is mistyped, then replace it with the correct name.
+ The example above can be fixed by changing `a` to `b`:
+
+ ```dart
+ %language=2.9
+ class C {
+ m({int b}) {}
+ }
+
+ void f(C c) {
+ c.m(b: 1);
+ }
+ ```
+
+ If a subclass adds a parameter with the name in question, then cast the
+ receiver to the subclass:
+
+ ```dart
+ %language=2.9
+ class C {
+ m({int b}) {}
+ }
+
+ class D extends C {
+ m({int a, int b}) {}
+ }
+
+ void f(C c) {
+ (c as D).m(a: 1);
+ }
+ ```
+
+ If the parameter should be added to the function, then add it:
+
+ ```dart
+ %language=2.9
+ class C {
+ m({int a, int b}) {}
+ }
+
+ void f(C c) {
+ c.m(a: 1);
+ }
+ ```
+ UNDEFINED_OPERATOR:
+ template: "The operator '{0}' isn't defined for the type '{1}'."
+ tip: "Try defining the operator '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the operator
+ 1: the name of the enclosing type where the operator is being looked for
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a user-definable operator is
+ invoked on an object for which the operator isn't defined.
+
+ #### Examples
+
+ The following code produces this diagnostic because the class `C` doesn't
+ define the operator `+`:
+
+ ```dart
+ class C {}
+
+ C f(C c) => c [!+!] 2;
+ ```
+
+ #### Common fixes
+
+ If the operator should be defined for the class, then define it:
+
+ ```dart
+ class C {
+ C operator +(int i) => this;
+ }
+
+ C f(C c) => c + 2;
+ ```
+ UNDEFINED_PREFIXED_NAME:
+ template: "The name '{0}' is being referenced through the prefix '{1}', but it isn't defined in any of the libraries imported using that prefix."
+ tip: "Try correcting the prefix or importing the library that defines '{0}'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a prefixed identifier is found
+ where the prefix is valid, but the identifier isn't declared in any of the
+ libraries imported using that prefix.
+
+ #### Examples
+
+ The following code produces this diagnostic because `dart:core` doesn't
+ define anything named `a`:
+
+ ```dart
+ import 'dart:core' as p;
+
+ void f() {
+ p.[!a!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the library in which the name is declared isn't imported yet, add an
+ import for the library.
+
+ If the name is wrong, then change it to one of the names that's declared in
+ the imported libraries.
+ UNDEFINED_SETTER:
+ template: "The setter '{0}' isn't defined for the type '{1}'."
+ tip: "Try importing the library that defines '{0}', correcting the name to the name of an existing setter, or defining a setter or field named '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the setter
+ 1: the name of the enclosing type where the setter is being looked for
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it encounters an identifier that
+ appears to be the name of a setter but either isn't defined or isn't
+ visible in the scope in which the identifier is being referenced.
+
+ #### Examples
+
+ The following code produces this diagnostic because there isn't a setter
+ named `z`:
+
+ ```dart
+ class C {
+ int x = 0;
+ void m(int y) {
+ this.[!z!] = y;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the identifier isn't defined, then either define it or replace it with
+ the name of a setter that is defined. The example above can be corrected by
+ fixing the spelling of the setter:
+
+ ```dart
+ class C {
+ int x = 0;
+ void m(int y) {
+ this.x = y;
+ }
+ }
+ ```
+ UNDEFINED_SETTER_ON_FUNCTION_TYPE:
+ sharedName: UNDEFINED_SETTER
+ template: "The setter '{0}' isn't defined for the '{1}' function type."
+ tip: "Try wrapping the function type alias in parentheses in order to access '{0}' as an extension getter on 'Type'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the setter
+ 1: the name of the function type alias
+ UNDEFINED_SUPER_GETTER:
+ sharedName: UNDEFINED_SUPER_MEMBER
+ template: "The getter '{0}' isn't defined in a superclass of '{1}'."
+ tip: "Try correcting the name to the name of an existing getter, or defining a getter or field named '{0}' in a superclass."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the getter
+ 1: the name of the enclosing type where the getter is being looked for
+ UNDEFINED_SUPER_METHOD:
+ sharedName: UNDEFINED_SUPER_MEMBER
+ template: "The method '{0}' isn't defined in a superclass of '{1}'."
+ tip: "Try correcting the name to the name of an existing method, or defining a method named '{0}' in a superclass."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the method that is undefined
+ 1: the resolved type name that the method lookup is happening on
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an inherited member (method,
+ getter, setter, or operator) is referenced using `super`, but there’s no
+ member with that name in the superclass chain.
+
+ #### Examples
+
+ The following code produces this diagnostic because `Object` doesn't define
+ a method named `n`:
+
+ ```dart
+ class C {
+ void m() {
+ super.[!n!]();
+ }
+ }
+ ```
+
+ The following code produces this diagnostic because `Object` doesn't define
+ a getter named `g`:
+
+ ```dart
+ class C {
+ void m() {
+ super.[!g!];
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the inherited member you intend to invoke has a different name, then
+ make the name of the invoked member match the inherited member.
+
+ If the member you intend to invoke is defined in the same class, then
+ remove the `super.`.
+
+ If the member isn’t defined, then either add the member to one of the
+ superclasses or remove the invocation.
+ UNDEFINED_SUPER_OPERATOR:
+ sharedName: UNDEFINED_SUPER_MEMBER
+ template: "The operator '{0}' isn't defined in a superclass of '{1}'."
+ tip: "Try defining the operator '{0}' in a superclass."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the operator
+ 1: the name of the enclosing type where the operator is being looked for
+ UNDEFINED_SUPER_SETTER:
+ sharedName: UNDEFINED_SUPER_MEMBER
+ template: "The setter '{0}' isn't defined in a superclass of '{1}'."
+ tip: "Try correcting the name to the name of an existing setter, or defining a setter or field named '{0}' in a superclass."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the setter
+ 1: the name of the enclosing type where the setter is being looked for
+ UNQUALIFIED_REFERENCE_TO_NON_LOCAL_STATIC_MEMBER:
+ template: Static members from supertypes must be qualified by the name of the defining type.
+ tip: "Try adding '{0}.' before the name."
+ hasPublishedDocs: true
+ comment: |-
+ This is a specialization of [INSTANCE_ACCESS_TO_STATIC_MEMBER] that is used
+ when we are able to find the name defined in a supertype. It exists to
+ provide a more informative error message.
+
+ Parameters:
+ 0: the name of the defining type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when code in one class references a
+ static member in a superclass without prefixing the member's name with the
+ name of the superclass. Static members can only be referenced without a
+ prefix in the class in which they're declared.
+
+ #### Example
+
+ The following code produces this diagnostic because the static field `x` is
+ referenced in the getter `g` without prefixing it with the name of the
+ defining class:
+
+ ```dart
+ class A {
+ static int x = 3;
+ }
+
+ class B extends A {
+ int get g => [!x!];
+ }
+ ```
+
+ #### Common fixes
+
+ Prefix the name of the static member with the name of the declaring class:
+
+ ```dart
+ class A {
+ static int x = 3;
+ }
+
+ class B extends A {
+ int get g => A.x;
+ }
+ ```
+ UNQUALIFIED_REFERENCE_TO_STATIC_MEMBER_OF_EXTENDED_TYPE:
+ template: Static members from the extended type or one of its superclasses must be qualified by the name of the defining type.
+ tip: "Try adding '{0}.' before the name."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the defining type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an undefined name is found, and
+ the name is the same as a static member of the extended type or one of its
+ superclasses.
+
+ #### Examples
+
+ The following code produces this diagnostic because `m` is a static member
+ of the extended type `C`:
+
+ ```dart
+ class C {
+ static void m() {}
+ }
+
+ extension E on C {
+ void f() {
+ [!m!]();
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If you're trying to reference a static member that's declared outside the
+ extension, then add the name of the class or extension before the reference
+ to the member:
+
+ ```dart
+ class C {
+ static void m() {}
+ }
+
+ extension E on C {
+ void f() {
+ C.m();
+ }
+ }
+ ```
+
+ If you're referencing a member that isn't declared yet, add a declaration:
+
+ ```dart
+ class C {
+ static void m() {}
+ }
+
+ extension E on C {
+ void f() {
+ m();
+ }
+
+ void m() {}
+ }
+ ```
+ URI_DOES_NOT_EXIST:
+ template: "Target of URI doesn't exist: '{0}'."
+ tip: Try creating the file referenced by the URI, or Try using a URI for a file that does exist.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the URI pointing to a non-existent file
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an import, export, or part
+ directive is found where the URI refers to a file that doesn't exist.
+
+ #### Examples
+
+ If the file `lib.dart` doesn't exist, the following code produces this
+ diagnostic:
+
+ ```dart
+ import [!'lib.dart'!];
+ ```
+
+ #### Common fixes
+
+ If the URI was mistyped or invalid, then correct the URI.
+
+ If the URI is correct, then create the file.
+ URI_HAS_NOT_BEEN_GENERATED:
+ template: "Target of URI hasn't been generated: '{0}'."
+ tip: Try running the generator that will generate the file referenced by the URI.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the URI pointing to a non-existent file
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an import, export, or part
+ directive is found where the URI refers to a file that doesn't exist and
+ the name of the file ends with a pattern that's commonly produced by code
+ generators, such as one of the following:
+ - `.g.dart`
+ - `.pb.dart`
+ - `.pbenum.dart`
+ - `.pbserver.dart`
+ - `.pbjson.dart`
+ - `.template.dart`
+
+ #### Examples
+
+ If the file `lib.g.dart` doesn't exist, the following code produces this
+ diagnostic:
+
+ ```dart
+ import [!'lib.g.dart'!];
+ ```
+
+ #### Common fixes
+
+ If the file is a generated file, then run the generator that generates the
+ file.
+
+ If the file isn't a generated file, then check the spelling of the URI or
+ create the file.
+ URI_WITH_INTERPOLATION:
+ template: "URIs can't use string interpolation."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the string literal in an
+ `import`, `export`, or `part` directive contains an interpolation. The
+ resolution of the URIs in directives must happen before the declarations
+ are compiled, so expressions can’t be evaluated while determining the
+ values of the URIs.
+
+ #### Example
+
+ The following code produces this diagnostic because the string in the
+ `import` directive contains an interpolation:
+
+ ```dart
+ import [!'dart:$m'!];
+
+ const m = 'math';
+ ```
+
+ #### Common fixes
+
+ Remove the interpolation from the URI:
+
+ ```dart
+ import 'dart:math';
+
+ var zero = min(0, 0);
+ ```
+ USE_OF_VOID_RESULT:
+ template: "This expression has a type of 'void' so its value can't be used."
+ tip: "Try checking to see if you're using the correct API; there might be a function or call that returns void you didn't expect. Also check type parameters and variables which might also be void."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds an expression whose
+ type is `void`, and the expression is used in a place where a value is
+ expected, such as before a member access or on the right-hand side of an
+ assignment.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` doesn't produce an
+ object on which `toString` can be invoked:
+
+ ```dart
+ void f() {}
+
+ void g() {
+ [!f()!].toString();
+ }
+ ```
+
+ #### Common fixes
+
+ Either rewrite the code so that the expression has a value or rewrite the
+ code so that it doesn't depend on the value.
+ VARIABLE_TYPE_MISMATCH:
+ template: "A value of type '{0}' can't be assigned to a const variable of type '{1}'."
+ tip: "Try using a subtype, or removing the 'const' keyword"
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the object being assigned.
+ 1: the type of the variable being assigned to
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the evaluation of a constant
+ expression would result in a `CastException`.
+
+ #### Examples
+
+ The following code produces this diagnostic because the value of `x` is an
+ `int`, which can't be assigned to `y` because an `int` isn't a `String`:
+
+ ```dart
+ %language=2.9
+ const Object x = 0;
+ const String y = [!x!];
+ ```
+
+ #### Common fixes
+
+ If the declaration of the constant is correct, then change the value being
+ assigned to be of the correct type:
+
+ ```dart
+ %language=2.9
+ const Object x = 0;
+ const String y = '$x';
+ ```
+
+ If the assigned value is correct, then change the declaration to have the
+ correct type:
+
+ ```dart
+ %language=2.9
+ const Object x = 0;
+ const int y = x;
+ ```
+ WRONG_EXPLICIT_TYPE_PARAMETER_VARIANCE_IN_SUPERINTERFACE:
+ template: "'{0}' is an '{1}' type parameter and can't be used in an '{2}' position in '{3}'."
+ tip: "Try using 'in' type parameters in 'in' positions and 'out' type parameters in 'out' positions in the superinterface."
+ comment: |-
+ Let `C` be a generic class that declares a formal type parameter `X`, and
+ assume that `T` is a direct superinterface of `C`.
+
+ It is a compile-time error if `X` is explicitly defined as a covariant or
+ 'in' type parameter and `X` occurs in a non-covariant position in `T`.
+ It is a compile-time error if `X` is explicitly defined as a contravariant
+ or 'out' type parameter and `X` occurs in a non-contravariant position in
+ `T`.
+
+ Parameters:
+ 0: the name of the type parameter
+ 1: the variance modifier defined for {0}
+ 2: the variance position of the type parameter {0} in the
+ superinterface {3}
+ 3: the name of the superinterface
+ WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR:
+ template: "Operator '{0}' should declare exactly {1} parameters, but {2} found."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the declared operator
+ 1: the number of parameters expected
+ 2: the number of parameters found in the operator declaration
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a declaration of an operator has
+ the wrong number of parameters.
+
+ #### Examples
+
+ The following code produces this diagnostic because the operator `+` must
+ have a single parameter corresponding to the right operand:
+
+ ```dart
+ class C {
+ int operator [!+!](a, b) => 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Add or remove parameters to match the required number:
+
+ ```dart
+ class C {
+ int operator +(a) => 0;
+ }
+ ```
+ TODO(brianwilkerson) It would be good to add a link to the spec or some
+ other documentation that lists the number of parameters for each operator,
+ but I don't know what to link to.
+ WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR_MINUS:
+ sharedName: WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR
+ template: "Operator '-' should declare 0 or 1 parameter, but {0} found."
+ hasPublishedDocs: true
+ comment: |-
+ 7.1.1 Operators: It is a compile time error if the arity of the
+ user-declared operator - is not 0 or 1.
+
+ Parameters:
+ 0: the number of parameters found in the operator declaration
+ WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER:
+ template: Setters must declare exactly one required positional parameter.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a setter is found that doesn't
+ declare exactly one required positional parameter.
+
+ #### Examples
+
+ The following code produces this diagnostic because the setter `s` declares
+ two required parameters:
+
+ ```dart
+ %language=2.9
+ class C {
+ set [!s!](int x, int y) {}
+ }
+ ```
+
+ The following code produces this diagnostic because the setter `s` declares
+ one optional parameter:
+
+ ```dart
+ %language=2.9
+ class C {
+ set [!s!]([int x]) {}
+ }
+ ```
+
+ #### Common fixes
+
+ Change the declaration so that there's exactly one required positional
+ parameter:
+
+ ```dart
+ %language=2.9
+ class C {
+ set s(int x) {}
+ }
+ ```
+ WRONG_NUMBER_OF_TYPE_ARGUMENTS:
+ template: "The type '{0}' is declared with {1} type parameters, but {2} type arguments were given."
+ tip: Try adjusting the number of type arguments to match the number of type parameters.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the type being referenced (<i>G</i>)
+ 1: the number of type parameters that were declared
+ 2: the number of type arguments provided
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a type that has type parameters
+ is used and type arguments are provided, but the number of type arguments
+ isn't the same as the number of type parameters.
+
+ The analyzer also produces this diagnostic when a constructor is invoked
+ and the number of type arguments doesn't match the number of type
+ parameters declared for the class.
+
+ #### Examples
+
+ The following code produces this diagnostic because `C` has one type
+ parameter but two type arguments are provided when it is used as a type
+ annotation:
+
+ ```dart
+ class C<E> {}
+
+ void f([!C<int, int>!] x) {}
+ ```
+
+ The following code produces this diagnostic because `C` declares one type
+ parameter, but two type arguments are provided when creating an instance:
+
+ ```dart
+ class C<E> {}
+
+ var c = [!C<int, int>!]();
+ ```
+
+ #### Common fixes
+
+ Add or remove type arguments, as necessary, to match the number of type
+ parameters defined for the type:
+
+ ```dart
+ class C<E> {}
+
+ void f(C<int> x) {}
+ ```
+ WRONG_NUMBER_OF_TYPE_ARGUMENTS_CONSTRUCTOR:
+ template: "The constructor '{0}.{1}' doesn't have type parameters."
+ tip: Try moving type arguments to after the type name.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the class being instantiated
+ 1: the name of the constructor being invoked
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when type arguments are provided
+ after the name of a named constructor. Constructors can't declare type
+ parameters, so invocations can only provide the type arguments associated
+ with the class, and those type arguments are required to follow the name of
+ the class rather than the name of the constructor.
+
+ #### Example
+
+ The following code produces this diagnostic because the type parameters
+ (`<String>`) follow the name of the constructor rather than the name of the
+ class:
+
+ ```dart
+ class C<T> {
+ C.named();
+ }
+ C f() => C.named[!<String>!]();
+ ```
+
+ #### Common fixes
+
+ If the type arguments are for the class' type parameters, then move the
+ type arguments to follow the class name:
+
+ ```dart
+ class C<T> {
+ C.named();
+ }
+ C f() => C<String>.named();
+ ```
+
+ If the type arguments aren't for the class' type parameters, then remove
+ them:
+
+ ```dart
+ class C<T> {
+ C.named();
+ }
+ C f() => C.named();
+ ```
+ WRONG_NUMBER_OF_TYPE_ARGUMENTS_EXTENSION:
+ template: "The extension '{0}' is declared with {1} type parameters, but {2} type arguments were given."
+ tip: Try adjusting the number of type arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the extension being referenced
+ 1: the number of type parameters that were declared
+ 2: the number of type arguments provided
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension that has type
+ parameters is used and type arguments are provided, but the number of type
+ arguments isn't the same as the number of type parameters.
+
+ #### Example
+
+ The following code produces this diagnostic because the extension `E` is
+ declared to have a single type parameter (`T`), but the extension override
+ has two type arguments:
+
+ ```dart
+ extension E<T> on List<T> {
+ int get len => length;
+ }
+
+ void f(List<int> p) {
+ E[!<int, String>!](p).len;
+ }
+ ```
+
+ #### Common fixes
+
+ Change the type arguments so that there are the same number of type
+ arguments as there are type parameters:
+
+ ```dart
+ extension E<T> on List<T> {
+ int get len => length;
+ }
+
+ void f(List<int> p) {
+ E<int>(p).len;
+ }
+ ```
+ WRONG_NUMBER_OF_TYPE_ARGUMENTS_ANONYMOUS_FUNCTION:
+ sharedName: WRONG_NUMBER_OF_TYPE_ARGUMENTS_FUNCTION
+ template: "This function is declared with {0} type parameters, but {1} type arguments were given."
+ tip: Try adjusting the number of type arguments to match the number of type parameters.
+ comment: |-
+ Parameters:
+ 0: the number of type parameters that were declared
+ 1: the number of type arguments provided
+ WRONG_NUMBER_OF_TYPE_ARGUMENTS_FUNCTION:
+ template: "The function '{0}' is declared with {1} type parameters, but {2} type arguments were given."
+ tip: Try adjusting the number of type arguments to match the number of type parameters.
+ comment: |-
+ Parameters:
+ 0: the name of the function being referenced
+ 1: the number of type parameters that were declared
+ 2: the number of type arguments provided
+ WRONG_NUMBER_OF_TYPE_ARGUMENTS_METHOD:
+ template: "The method '{0}' is declared with {1} type parameters, but {2} type arguments are given."
+ tip: Try adjusting the number of type arguments.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the method being referenced (<i>G</i>)
+ 1: the number of type parameters that were declared
+ 2: the number of type arguments provided
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function is invoked
+ with a different number of type arguments than the number of type
+ parameters specified in its declaration. There must either be no type
+ arguments or the number of arguments must match the number of parameters.
+
+ #### Example
+
+ The following code produces this diagnostic because the invocation of the
+ method `m` has two type arguments, but the declaration of `m` only has one
+ type parameter:
+
+ ```dart
+ class C {
+ int m<A>(A a) => 0;
+ }
+
+ int f(C c) => c.m[!<int, int>!](2);
+ ```
+
+ #### Common fixes
+
+ If the type arguments are necessary, then make them match the number of
+ type parameters by either adding or removing type arguments:
+
+ ```dart
+ class C {
+ int m<A>(A a) => 0;
+ }
+
+ int f(C c) => c.m<int>(2);
+ ```
+
+ If the type arguments aren't necessary, then remove them:
+
+ ```dart
+ class C {
+ int m<A>(A a) => 0;
+ }
+
+ int f(C c) => c.m(2);
+ ```
+ WRONG_TYPE_PARAMETER_VARIANCE_IN_SUPERINTERFACE:
+ template: "'{0}' can't be used contravariantly or invariantly in '{1}'."
+ tip: Try not using class type parameters in types of formal parameters of function types, nor in explicitly contravariant or invariant superinterfaces.
+ comment: |-
+ Let `C` be a generic class that declares a formal type parameter `X`, and
+ assume that `T` is a direct superinterface of `C`. It is a compile-time
+ error if `X` occurs contravariantly or invariantly in `T`.
+ WRONG_TYPE_PARAMETER_VARIANCE_POSITION:
+ template: "The '{0}' type parameter '{1}' can't be used in an '{2}' position."
+ tip: "Try removing the type parameter or change the explicit variance modifier declaration for the type parameter to another one of 'in', 'out', or 'inout'."
+ comment: |-
+ Let `C` be a generic class that declares a formal type parameter `X`.
+
+ If `X` is explicitly contravariant then it is a compile-time error for
+ `X` to occur in a non-contravariant position in a member signature in the
+ body of `C`, except when `X` is in a contravariant position in the type
+ annotation of a covariant formal parameter.
+
+ If `X` is explicitly covariant then it is a compile-time error for
+ `X` to occur in a non-covariant position in a member signature in the
+ body of `C`, except when `X` is in a covariant position in the type
+ annotation of a covariant formal parameter.
+
+ Parameters:
+ 0: the variance modifier defined for {0}
+ 1: the name of the type parameter
+ 2: the variance position that the type parameter {1} is in
+ YIELD_EACH_IN_NON_GENERATOR:
+ sharedName: YIELD_IN_NON_GENERATOR
+ template: "Yield-each statements must be in a generator function (one marked with either 'async*' or 'sync*')."
+ tip: "Try adding 'async*' or 'sync*' to the enclosing function."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `yield` or `yield*` statement
+ appears in a function whose body isn't marked with one of the `async*` or
+ `sync*` modifiers.
+
+ #### Example
+
+ The following code produces this diagnostic because `yield` is being used
+ in a function whose body doesn't have a modifier:
+
+ ```dart
+ Iterable<int> get digits {
+ yield* [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+ }
+ ```
+
+ The following code produces this diagnostic because `yield*` is being used
+ in a function whose body has the `async` modifier rather than the `async*`
+ modifier:
+
+ ```dart
+ Stream<int> get digits async {
+ yield* [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+ }
+ ```
+
+ #### Common fixes
+
+ Add a modifier, or change the existing modifier to be either `async*` or
+ `sync*`:
+
+ ```dart
+ Iterable<int> get digits sync* {
+ yield* [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+ }
+ ```
+ YIELD_IN_NON_GENERATOR:
+ template: "Yield statements must be in a generator function (one marked with either 'async*' or 'sync*')."
+ tip: "Try adding 'async*' or 'sync*' to the enclosing function."
+ hasPublishedDocs: true
+ comment: |-
+ ?? Yield: It is a compile-time error if a yield statement appears in a
+ function that is not a generator function.
+
+ No parameters.
+ YIELD_OF_INVALID_TYPE:
+ template: "The type '{0}' implied by the 'yield' expression must be assignable to '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the type of the expression after `yield`
+ 1: the return type of the function containing the `yield`
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type of object produced by a
+ `yield` expression doesn't match the type of objects that are to be
+ returned from the `Iterable` or `Stream` types that are returned from a
+ generator (a function or method marked with either `sync*` or `async*`).
+
+ #### Example
+
+ The following code produces this diagnostic because the getter `zero` is
+ declared to return an `Iterable` that returns integers, but the `yield` is
+ returning a string from the iterable:
+
+ ```dart
+ Iterable<int> get zero sync* {
+ yield [!'0'!];
+ }
+ ```
+
+ #### Common fixes
+
+ If the return type of the function is correct, then fix the expression
+ following the keyword `yield` to return the correct type:
+
+ ```dart
+ Iterable<int> get zero sync* {
+ yield 0;
+ }
+ ```
+
+ If the expression following the `yield` is correct, then change the return
+ type of the function to allow it:
+
+ ```dart
+ Iterable<String> get zero sync* {
+ yield '0';
+ }
+ ```
+FfiCode:
+ ANNOTATION_ON_POINTER_FIELD:
+ template: "Fields in a struct class whose type is 'Pointer' should not have any annotations."
+ tip: Try removing the annotation.
+ comment: No parameters.
+ ARGUMENT_MUST_BE_A_CONSTANT:
+ template: "Argument '{0}' must be a constant."
+ tip: Try replacing the value with a literal or const.
+ comment: |-
+ Parameters:
+ 0: the name of the argument
+ CREATION_OF_STRUCT_OR_UNION:
+ template: "Subclasses of 'Struct' and 'Union' are backed by native memory, and can't be instantiated by a generative constructor."
+ tip: "Try allocating it via allocation, or load from a 'Pointer'."
+ comment: No parameters.
+ EMPTY_STRUCT:
+ template: "Struct '{0}' is empty. Empty structs are undefined behavior."
+ tip: "Try adding a field to '{0}' or use a different Struct."
+ comment: |-
+ Parameters:
+ 0: the name of the struct class
+ EXTRA_ANNOTATION_ON_STRUCT_FIELD:
+ template: Fields in a struct class must have exactly one annotation indicating the native type.
+ tip: Try removing the extra annotation.
+ comment: No parameters.
+ EXTRA_SIZE_ANNOTATION_CARRAY:
+ template: "'Array's must have exactly one 'Array' annotation."
+ tip: Try removing the extra annotation.
+ comment: No parameters.
+ FFI_NATIVE_ONLY_STATIC:
+ template: FfiNative annotations can only be used on static functions.
+ tip: Change the method to static.
+ comment: No parameters.
+ FIELD_INITIALIZER_IN_STRUCT:
+ template: "Constructors in subclasses of 'Struct' and 'Union' can't have field initializers."
+ tip: Try removing the field initializer and marking the field as external.
+ comment: No parameters.
+ FIELD_IN_STRUCT_WITH_INITIALIZER:
+ template: "Fields in subclasses of 'Struct' and 'Union' can't have initializers."
+ tip: Try removing the initializer and marking the field as external.
+ comment: No parameters.
+ FIELD_MUST_BE_EXTERNAL_IN_STRUCT:
+ template: "Fields of 'Struct' and 'Union' subclasses must be marked external."
+ tip: "Try adding the 'external' modifier."
+ comment: No parameters.
+ GENERIC_STRUCT_SUBCLASS:
+ template: "The class '{0}' can't extend 'Struct' or 'Union' because it is generic."
+ tip: "Try removing the type parameters from '{0}'."
+ comment: |-
+ Parameters:
+ 0: the name of the struct class
+ INVALID_EXCEPTION_VALUE:
+ template: "The method 'Pointer.fromFunction' must not have an exceptional return value (the second argument) when the return type of the function is either 'void', 'Handle' or 'Pointer'."
+ tip: Try removing the exceptional return value.
+ comment: No parameters.
+ INVALID_FIELD_TYPE_IN_STRUCT:
+ template: "Fields in struct classes can't have the type '{0}'. They can only be declared as 'int', 'double', 'Array', 'Pointer', or subtype of 'Struct' or 'Union'."
+ tip: "Try using 'int', 'double', 'Array', 'Pointer', or subtype of 'Struct' or 'Union'."
+ comment: |-
+ Parameters:
+ 0: the type of the field
+ LEAF_CALL_MUST_NOT_RETURN_HANDLE:
+ template: FFI leaf call must not return a Handle.
+ tip: Try changing the return type to primitive or struct.
+ comment: No parameters.
+ LEAF_CALL_MUST_NOT_TAKE_HANDLE:
+ template: FFI leaf call must not take arguments of type Handle.
+ tip: Try changing the argument type to primitive or struct.
+ comment: No parameters.
+ MISMATCHED_ANNOTATION_ON_STRUCT_FIELD:
+ template: The annotation does not match the declared type of the field.
+ tip: Try using a different annotation or changing the declared type to match.
+ comment: No parameters.
+ MISSING_ANNOTATION_ON_STRUCT_FIELD:
+ template: "Fields in a struct class must either have the type 'Pointer' or an annotation indicating the native type."
+ tip: Try adding an annotation.
+ comment: No parameters.
+ MISSING_EXCEPTION_VALUE:
+ template: "The method 'Pointer.fromFunction' must have an exceptional return value (the second argument) when the return type of the function is neither 'void', 'Handle' or 'Pointer'."
+ tip: Try adding an exceptional return value.
+ comment: No parameters.
+ MISSING_FIELD_TYPE_IN_STRUCT:
+ template: "Fields in struct classes must have an explicitly declared type of 'int', 'double' or 'Pointer'."
+ tip: "Try using 'int', 'double' or 'Pointer'."
+ comment: |-
+ Parameters:
+ 0: the type of the field
+ MISSING_SIZE_ANNOTATION_CARRAY:
+ template: "'Array's must have exactly one 'Array' annotation."
+ tip: "Try adding a 'Array' annotation."
+ comment: No parameters.
+ MUST_BE_A_NATIVE_FUNCTION_TYPE:
+ template: "The type '{0}' given to '{1}' must be a valid 'dart:ffi' native function type."
+ tip: "Try changing the type to only use members for 'dart:ffi'."
+ comment: |-
+ Parameters:
+ 0: the type that should be a valid dart:ffi native type.
+ 1: the name of the function whose invocation depends on this relationship
+ MUST_BE_A_SUBTYPE:
+ template: "The type '{0}' must be a subtype of '{1}' for '{2}'."
+ tip: Try changing one or both of the type arguments.
+ comment: |-
+ Parameters:
+ 0: the type that should be a subtype
+ 1: the supertype that the subtype is compared to
+ 2: the name of the function whose invocation depends on this relationship
+ NON_CONSTANT_TYPE_ARGUMENT:
+ template: "The type arguments to '{0}' must be compile time constants but type parameters are not constants."
+ tip: Try changing the type argument to be a constant type.
+ comment: |-
+ Parameters:
+ 0: the name of the function, method, or constructor having type arguments
+ NON_NATIVE_FUNCTION_TYPE_ARGUMENT_TO_POINTER:
+ template: "The type argument for the pointer '{0}' must be a 'NativeFunction' in order to use 'asFunction'."
+ tip: "Try changing the type argument to be a 'NativeFunction'."
+ comment: |-
+ Parameters:
+ 0: the type that should be a valid dart:ffi native type.
+ NON_POSITIVE_ARRAY_DIMENSION:
+ template: Array dimensions must be positive numbers.
+ tip: Try changing the input to a positive number.
+ comment: No parameters.
+ NON_SIZED_TYPE_ARGUMENT:
+ template: "Type arguments to '{0}' can't have the type '{1}'. They can only be declared as native integer, 'Float', 'Double', 'Pointer', or subtype of 'Struct' or 'Union'."
+ tip: "Try using a native integer, 'Float', 'Double', 'Pointer', or subtype of 'Struct' or 'Union'."
+ comment: |-
+ Parameters:
+ 0: the type of the field
+ PACKED_ANNOTATION:
+ template: "Structs must have at most one 'Packed' annotation."
+ tip: "Try removing extra 'Packed' annotations."
+ comment: No parameters.
+ PACKED_ANNOTATION_ALIGNMENT:
+ template: Only packing to 1, 2, 4, 8, and 16 bytes is supported.
+ tip: "Try changing the 'Packed' annotation alignment to 1, 2, 4, 8, or 16."
+ comment: No parameters.
+ PACKED_NESTING_NON_PACKED:
+ template: "Nesting the non-packed or less tightly packed struct '{0}' in a packed struct '{1}' is not supported."
+ tip: Try packing the nested struct or packing the nested struct more tightly.
+ comment: |-
+ Parameters:
+ 0: the name of the outer struct
+ 1: the name of the struct being nested
+ SIZE_ANNOTATION_DIMENSIONS:
+ template: "'Array's must have an 'Array' annotation that matches the dimensions."
+ tip: "Try adjusting the arguments in the 'Array' annotation."
+ comment: No parameters.
+ SUBTYPE_OF_FFI_CLASS_IN_EXTENDS:
+ sharedName: SUBTYPE_OF_FFI_CLASS
+ template: "The class '{0}' can't extend '{1}'."
+ tip: "Try extending 'Struct' or 'Union'."
+ comment: |-
+ Parameters:
+ 0: the name of the subclass
+ 1: the name of the class being extended, implemented, or mixed in
+ SUBTYPE_OF_FFI_CLASS_IN_IMPLEMENTS:
+ sharedName: SUBTYPE_OF_FFI_CLASS
+ template: "The class '{0}' can't implement '{1}'."
+ tip: "Try extending 'Struct' or 'Union'."
+ comment: |-
+ Parameters:
+ 0: the name of the subclass
+ 1: the name of the class being extended, implemented, or mixed in
+ SUBTYPE_OF_FFI_CLASS_IN_WITH:
+ sharedName: SUBTYPE_OF_FFI_CLASS
+ template: "The class '{0}' can't mix in '{1}'."
+ tip: "Try extending 'Struct' or 'Union'."
+ comment: |-
+ Parameters:
+ 0: the name of the subclass
+ 1: the name of the class being extended, implemented, or mixed in
+ SUBTYPE_OF_STRUCT_CLASS_IN_EXTENDS:
+ sharedName: SUBTYPE_OF_STRUCT_CLASS
+ template: "The class '{0}' can't extend '{1}' because '{1}' is a subtype of 'Struct' or 'Union'."
+ tip: "Try extending 'Struct' or 'Union' directly."
+ comment: |-
+ Parameters:
+ 0: the name of the subclass
+ 1: the name of the class being extended, implemented, or mixed in
+ SUBTYPE_OF_STRUCT_CLASS_IN_IMPLEMENTS:
+ sharedName: SUBTYPE_OF_STRUCT_CLASS
+ template: "The class '{0}' can't implement '{1}' because '{1}' is a subtype of 'Struct' or 'Union'."
+ tip: "Try extending 'Struct' or 'Union' directly."
+ comment: |-
+ Parameters:
+ 0: the name of the subclass
+ 1: the name of the class being extended, implemented, or mixed in
+ SUBTYPE_OF_STRUCT_CLASS_IN_WITH:
+ sharedName: SUBTYPE_OF_STRUCT_CLASS
+ template: "The class '{0}' can't mix in '{1}' because '{1}' is a subtype of 'Struct' or 'Union'."
+ tip: "Try extending 'Struct' or 'Union' directly."
+ comment: |-
+ Parameters:
+ 0: the name of the subclass
+ 1: the name of the class being extended, implemented, or mixed in
+HintCode:
+ ARGUMENT_TYPE_NOT_ASSIGNABLE_TO_ERROR_HANDLER:
+ template: "The argument type '{0}' can't be assigned to the parameter type '{1} Function(Object)' or '{1} Function(Object, StackTrace)'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the actual argument type
+ 1: the name of the expected function return type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an invocation of
+ `Future.catchError` has an argument that is a function whose parameters
+ aren't compatible with the arguments that will be passed to the function
+ when it's invoked. The static type of the first argument to `catchError`
+ is just `Function`, even though the function that is passed in is expected
+ to have either a single parameter of type `Object` or two parameters of
+ type `Object` and `StackTrace`.
+
+ #### Example
+
+ The following code produces this diagnostic because the closure being
+ passed to `catchError` doesn't take any parameters, but the function is
+ required to take at least one parameter:
+
+ ```dart
+ void f(Future<int> f) {
+ f.catchError([!() => 0!]);
+ }
+ ```
+
+ The following code produces this diagnostic because the closure being
+ passed to `catchError` takes three parameters, but it can't have more than
+ two required parameters:
+
+ ```dart
+ void f(Future<int> f) {
+ f.catchError([!(one, two, three) => 0!]);
+ }
+ ```
+
+ The following code produces this diagnostic because even though the closure
+ being passed to `catchError` takes one parameter, the closure doesn't have
+ a type that is compatible with `Object`:
+
+ ```dart
+ void f(Future<int> f) {
+ f.catchError([!(String error) => 0!]);
+ }
+ ```
+
+ #### Common fixes
+
+ Change the function being passed to `catchError` so that it has either one
+ or two required parameters, and the parameters have the required types:
+
+ ```dart
+ void f(Future<int> f) {
+ f.catchError((Object error) => 0);
+ }
+ ```
+ ASSIGNMENT_OF_DO_NOT_STORE:
+ template: "'{0}' is marked 'doNotStore' and shouldn't be assigned to a field or top-level variable."
+ tip: Try removing the assignment.
+ comment: Users should not assign values marked `@doNotStore`.
+ CAN_BE_NULL_AFTER_NULL_AWARE:
+ template: "The receiver uses '?.', so its value can be null."
+ tip: "Replace the '.' with a '?.' in the invocation."
+ comment: |-
+ When the target expression uses '?.' operator, it can be `null`, so all the
+ subsequent invocations should also use '?.' operator.
+ DEAD_CODE:
+ template: Dead code.
+ tip: Try removing the code, or fixing the code before it so that it can be reached.
+ hasPublishedDocs: true
+ comment: |-
+ Dead code is code that is never reached, this can happen for instance if a
+ statement follows a return statement.
+
+ No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when code is found that won't be
+ executed because execution will never reach the code.
+
+ #### Examples
+
+ The following code produces this diagnostic because the invocation of
+ `print` occurs after the function has returned:
+
+ ```dart
+ void f() {
+ return;
+ [!print('here');!]
+ }
+ ```
+
+ #### Common fixes
+
+ If the code isn't needed, then remove it:
+
+ ```dart
+ void f() {
+ return;
+ }
+ ```
+
+ If the code needs to be executed, then either move the code to a place
+ where it will be executed:
+
+ ```dart
+ void f() {
+ print('here');
+ return;
+ }
+ ```
+
+ Or, rewrite the code before it, so that it can be reached:
+
+ ```dart
+ void f({bool skipPrinting = true}) {
+ if (skipPrinting) {
+ return;
+ }
+ print('here');
+ }
+ ```
+ DEAD_CODE_CATCH_FOLLOWING_CATCH:
+ template: "Dead code: Catch clauses after a 'catch (e)' or an 'on Object catch (e)' are never reached."
+ tip: Try reordering the catch clauses so that they can be reached, or removing the unreachable catch clauses.
+ hasPublishedDocs: true
+ comment: |-
+ Dead code is code that is never reached. This case covers cases where the
+ user has catch clauses after `catch (e)` or `on Object catch (e)`.
+
+ No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `catch` clause is found that
+ can't be executed because it’s after a `catch` clause of the form
+ `catch (e)` or `on Object catch (e)`. The first `catch` clause that matches
+ the thrown object is selected, and both of those forms will match any
+ object, so no `catch` clauses that follow them will be selected.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ void f() {
+ try {
+ } catch (e) {
+ } [!on String {
+ }!]
+ }
+ ```
+
+ #### Common fixes
+
+ If the clause should be selectable, then move the clause before the general
+ clause:
+
+ ```dart
+ void f() {
+ try {
+ } on String {
+ } catch (e) {
+ }
+ }
+ ```
+
+ If the clause doesn't need to be selectable, then remove it:
+
+ ```dart
+ void f() {
+ try {
+ } catch (e) {
+ }
+ }
+ ```
+ DEAD_CODE_ON_CATCH_SUBTYPE:
+ template: "Dead code: This on-catch block won’t be executed because '{0}' is a subtype of '{1}' and hence will have been caught already."
+ tip: Try reordering the catch clauses so that this block can be reached, or removing the unreachable catch clause.
+ hasPublishedDocs: true
+ comment: |-
+ Dead code is code that is never reached. This case covers cases where the
+ user has an on-catch clause such as `on A catch (e)`, where a supertype of
+ `A` was already caught.
+
+ Parameters:
+ 0: name of the subtype
+ 1: name of the supertype
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `catch` clause is found that
+ can't be executed because it is after a `catch` clause that catches either
+ the same type or a supertype of the clause's type. The first `catch` clause
+ that matches the thrown object is selected, and the earlier clause always
+ matches anything matchable by the highlighted clause, so the highlighted
+ clause will never be selected.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ void f() {
+ try {
+ } on num {
+ } [!on int {
+ }!]
+ }
+ ```
+
+ #### Common fixes
+
+ If the clause should be selectable, then move the clause before the general
+ clause:
+
+ ```dart
+ void f() {
+ try {
+ } on int {
+ } on num {
+ }
+ }
+ ```
+
+ If the clause doesn't need to be selectable, then remove it:
+
+ ```dart
+ void f() {
+ try {
+ } on num {
+ }
+ }
+ ```
+ DEPRECATED_FUNCTION_CLASS_DECLARATION:
+ template: "Declaring a class named 'Function' is deprecated."
+ tip: Try renaming the class.
+ comment: Users should not create a class named `Function` anymore.
+ DEPRECATED_MEMBER_USE:
+ template: "'{0}' is deprecated and shouldn't be used."
+ tip: Try replacing the use of the deprecated member with the replacement.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a deprecated library or class
+ member is used in a different package.
+
+ #### Examples
+
+ If the method `m` in the class `C` is annotated with `@deprecated`, then
+ the following code produces this diagnostic:
+
+ ```dart
+ void f(C c) {
+ c.[!m!]();
+ }
+ ```
+
+ #### Common fixes
+
+ The documentation for declarations that are annotated with `@deprecated`
+ should indicate what code to use in place of the deprecated code.
+ DEPRECATED_MEMBER_USE_WITH_MESSAGE:
+ sharedName: DEPRECATED_MEMBER_USE
+ template: "'{0}' is deprecated and shouldn't be used. {1}."
+ tip: Try replacing the use of the deprecated member with the replacement.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ 1: message details
+ DEPRECATED_MEMBER_USE_FROM_SAME_PACKAGE:
+ template: "'{0}' is deprecated and shouldn't be used."
+ tip: Try replacing the use of the deprecated member with the replacement.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a deprecated library member or
+ class member is used in the same package in which it's declared.
+
+ #### Examples
+
+ The following code produces this diagnostic because `x` is deprecated:
+
+ ```dart
+ @deprecated
+ var x = 0;
+ var y = [!x!];
+ ```
+
+ #### Common fixes
+
+ The fix depends on what's been deprecated and what the replacement is. The
+ documentation for deprecated declarations should indicate what code to use
+ in place of the deprecated code.
+ DEPRECATED_MEMBER_USE_FROM_SAME_PACKAGE_WITH_MESSAGE:
+ sharedName: DEPRECATED_MEMBER_USE_FROM_SAME_PACKAGE
+ template: "'{0}' is deprecated and shouldn't be used. {1}."
+ tip: Try replacing the use of the deprecated member with the replacement.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ 1: message details
+ DEPRECATED_MIXIN_FUNCTION:
+ sharedName: DEPRECATED_SUBTYPE_OF_FUNCTION
+ template: "Mixing in 'Function' is deprecated."
+ tip: "Try removing 'Function' from the 'with' clause."
+ hasPublishedDocs: true
+ comment: No parameters.
+ DEPRECATED_IMPLEMENTS_FUNCTION:
+ sharedName: DEPRECATED_SUBTYPE_OF_FUNCTION
+ template: "Implementing 'Function' has no effect."
+ tip: "Try removing 'Function' from the 'implements' clause."
+ hasPublishedDocs: true
+ comment: No parameters.
+ DEPRECATED_EXTENDS_FUNCTION:
+ sharedName: DEPRECATED_SUBTYPE_OF_FUNCTION
+ template: "Extending 'Function' is deprecated."
+ tip: "Try removing 'Function' from the 'extends' clause."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the class `Function` is used in
+ either the `extends`, `implements`, or `with` clause of a class or mixin.
+ Using the class `Function` in this way has no semantic value, so it's
+ effectively dead code.
+
+ #### Example
+
+ The following code produces this diagnostic because `Function` is used as
+ the superclass of `F`:
+
+ ```dart
+ class F extends [!Function!] {}
+ ```
+
+ #### Common fixes
+
+ Remove the class `Function` from whichever clause it's in, and remove the
+ whole clause if `Function` is the only type in the clause:
+
+ ```dart
+ class F {}
+ ```
+ DIVISION_OPTIMIZATION:
+ template: The operator x ~/ y is more efficient than (x / y).toInt().
+ tip: "Try re-writing the expression to use the '~/' operator."
+ comment: Hint to use the ~/ operator.
+ DUPLICATE_HIDDEN_NAME:
+ template: Duplicate hidden name.
+ tip: Try removing the repeated name from the list of hidden members.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name occurs multiple times in
+ a `hide` clause. Repeating the name is unnecessary.
+
+ #### Example
+
+ The following code produces this diagnostic because the name `min` is
+ hidden more than once:
+
+ ```dart
+ import 'dart:math' hide min, [!min!];
+
+ var x = pi;
+ ```
+
+ #### Common fixes
+
+ If the name was mistyped in one or more places, then correct the mistyped
+ names:
+
+ ```dart
+ import 'dart:math' hide max, min;
+
+ var x = pi;
+ ```
+
+ If the name wasn't mistyped, then remove the unnecessary name from the
+ list:
+
+ ```dart
+ import 'dart:math' hide min;
+
+ var x = pi;
+ ```
+ DUPLICATE_IGNORE:
+ template: "The diagnostic '{0}' doesn't need to be ignored here because it's already being ignored."
+ tip: Try removing the name from the list, or removing the whole comment if this is the only name in the list.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the diagnostic being ignored
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a diagnostic name appears in an
+ `ignore` comment, but the diagnostic is already being ignored, either
+ because it's already included in the same `ignore` comment or because it
+ appears in an `ignore-in-file` comment.
+
+ #### Example
+
+ The following code produces this diagnostic because the diagnostic named
+ `unused_local_variable` is already being ignored for the whole file so it
+ doesn't need to be ignored on a specific line:
+
+ ```dart
+ // ignore_for_file: unused_local_variable
+ void f() {
+ // ignore: [!unused_local_variable!]
+ var x = 0;
+ }
+ ```
+
+ The following code produces this diagnostic because the diagnostic named
+ `unused_local_variable` is being ignored twice on the same line:
+
+ ```dart
+ void f() {
+ // ignore: unused_local_variable, [!unused_local_variable!]
+ var x = 0;
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the ignore comment, or remove the unnecessary diagnostic name if the
+ ignore comment is ignoring more than one diagnostic:
+
+ ```dart
+ // ignore_for_file: unused_local_variable
+ void f() {
+ var x = 0;
+ }
+ ```
+ DUPLICATE_IMPORT:
+ template: Duplicate import.
+ tip: Try removing all but one import of the library.
+ hasPublishedDocs: true
+ comment: |-
+ Duplicate imports.
+
+ No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an import directive is found
+ that is the same as an import before it in the file. The second import
+ doesn’t add value and should be removed.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ import 'package:meta/meta.dart';
+ import [!'package:meta/meta.dart'!];
+
+ @sealed class C {}
+ ```
+
+ #### Common fixes
+
+ Remove the unnecessary import:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ @sealed class C {}
+ ```
+ DUPLICATE_SHOWN_NAME:
+ template: Duplicate shown name.
+ tip: Try removing the repeated name from the list of shown members.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a name occurs multiple times in
+ a `show` clause. Repeating the name is unnecessary.
+
+ #### Example
+
+ The following code produces this diagnostic because the name `min` is shown
+ more than once:
+
+ ```dart
+ import 'dart:math' show min, [!min!];
+
+ var x = min(2, min(0, 1));
+ ```
+
+ #### Common fixes
+
+ If the name was mistyped in one or more places, then correct the mistyped
+ names:
+
+ ```dart
+ import 'dart:math' show max, min;
+
+ var x = max(2, min(0, 1));
+ ```
+
+ If the name wasn't mistyped, then remove the unnecessary name from the
+ list:
+
+ ```dart
+ import 'dart:math' show min;
+
+ var x = min(2, min(0, 1));
+ ```
+ EQUAL_ELEMENTS_IN_SET:
+ template: "Two elements in a set literal shouldn't be equal."
+ tip: Change or remove the duplicate element.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an element in a non-constant set
+ is the same as a previous element in the same set. If two elements are the
+ same, then the second value is ignored, which makes having both elements
+ pointless and likely signals a bug.
+
+ #### Example
+
+ The following code produces this diagnostic because the element `1` appears
+ twice:
+
+ ```dart
+ const a = 1;
+ const b = 1;
+ var s = <int>{a, [!b!]};
+ ```
+
+ #### Common fixes
+
+ If both elements should be included in the set, then change one of the
+ elements:
+
+ ```dart
+ const a = 1;
+ const b = 2;
+ var s = <int>{a, b};
+ ```
+
+ If only one of the elements is needed, then remove the one that isn't
+ needed:
+
+ ```dart
+ const a = 1;
+ var s = <int>{a};
+ ```
+
+ Note that literal sets preserve the order of their elements, so the choice
+ of which element to remove might affect the order in which elements are
+ returned by an iterator.
+ EQUAL_KEYS_IN_MAP:
+ template: "Two keys in a map literal shouldn't be equal."
+ tip: Change or remove the duplicate key.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a key in a non-constant map is
+ the same as a previous key in the same map. If two keys are the same, then
+ the second value overwrites the first value, which makes having both pairs
+ pointless and likely signals a bug.
+
+ #### Example
+
+ The following code produces this diagnostic because the keys `a` and `b`
+ have the same value:
+
+ ```dart
+ const a = 1;
+ const b = 1;
+ var m = <int, String>{a: 'a', [!b!]: 'b'};
+ ```
+
+ #### Common fixes
+
+ If both entries should be included in the map, then change one of the keys:
+
+ ```dart
+ const a = 1;
+ const b = 2;
+ var m = <int, String>{a: 'a', b: 'b'};
+ ```
+
+ If only one of the entries is needed, then remove the one that isn't
+ needed:
+
+ ```dart
+ const a = 1;
+ var m = <int, String>{a: 'a'};
+ ```
+
+ Note that literal maps preserve the order of their entries, so the choice
+ of which entry to remove might affect the order in which the keys and
+ values are returned by an iterator.
+ FILE_IMPORT_INSIDE_LIB_REFERENCES_FILE_OUTSIDE:
+ template: "A file in the 'lib' directory shouldn't import a file outside the 'lib' directory."
+ tip: "Try removing the import, or moving the imported file inside the 'lib' directory."
+ comment: |-
+ It is a bad practice for a source file in a package "lib" directory
+ hierarchy to traverse outside that directory hierarchy. For example, a
+ source file in the "lib" directory should not contain a directive such as
+ `import '../web/some.dart'` which references a file outside the lib
+ directory.
+ FILE_IMPORT_OUTSIDE_LIB_REFERENCES_FILE_INSIDE:
+ template: "A file outside the 'lib' directory shouldn't reference a file inside the 'lib' directory using a relative path."
+ tip: "Try using a package: URI instead."
+ comment: |-
+ It is a bad practice for a source file ouside a package "lib" directory
+ hierarchy to traverse into that directory hierarchy. For example, a source
+ file in the "web" directory should not contain a directive such as
+ `import '../lib/some.dart'` which references a file inside the lib
+ directory.
+ IMPORT_DEFERRED_LIBRARY_WITH_LOAD_FUNCTION:
+ template: "The imported library defines a top-level function named 'loadLibrary' that is hidden by deferring this library."
+ tip: Try changing the import to not be deferred, or rename the function in the imported library.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a library that declares a
+ function named `loadLibrary` is imported using a deferred import. A
+ deferred import introduces an implicit function named `loadLibrary`. This
+ function is used to load the contents of the deferred library, and the
+ implicit function hides the explicit declaration in the deferred library.
+
+ For more information, see the language tour's coverage of
+ [deferred loading](https://dart.dev/guides/language/language-tour#lazily-loading-a-library).
+
+ #### Example
+
+ Given a file (`a.dart`) that defines a function named `loadLibrary`:
+
+ ```dart
+ %uri="lib/a.dart"
+ void loadLibrary(Library library) {}
+
+ class Library {}
+ ```
+
+ The following code produces this diagnostic because the implicit
+ declaration of `a.loadLibrary` is hiding the explicit declaration of
+ `loadLibrary` in `a.dart`:
+
+ ```dart
+ [!import 'a.dart' deferred as a;!]
+
+ void f() {
+ a.Library();
+ }
+ ```
+
+ #### Common fixes
+
+ If the imported library isn't required to be deferred, then remove the
+ keyword `deferred`:
+
+ ```dart
+ import 'a.dart' as a;
+
+ void f() {
+ a.Library();
+ }
+ ```
+
+ If the imported library is required to be deferred and you need to
+ reference the imported function, then rename the function in the imported
+ library:
+
+ ```dart
+ void populateLibrary(Library library) {}
+
+ class Library {}
+ ```
+
+ If the imported library is required to be deferred and you don't need to
+ reference the imported function, then add a `hide` clause:
+
+ ```dart
+ import 'a.dart' deferred as a hide loadLibrary;
+
+ void f() {
+ a.Library();
+ }
+ ```
+
+ If type arguments shouldn't be required for the class, then mark the class
+ with the `@optionalTypeArgs` annotation (from `package:meta`):
+ IMPORT_OF_LEGACY_LIBRARY_INTO_NULL_SAFE:
+ template: "The library '{0}' is legacy, and should not be imported into a null safe library."
+ tip: Try migrating the imported library.
+ comment: "https://github.com/dart-lang/sdk/issues/44063"
+ INFERENCE_FAILURE_ON_COLLECTION_LITERAL:
+ template: "The type argument(s) of '{0}' can't be inferred."
+ tip: "Use explicit type argument(s) for '{0}'."
+ comment: |-
+ When "strict-inference" is enabled, collection literal types must be
+ inferred via the context type, or have type arguments.
+ INFERENCE_FAILURE_ON_FUNCTION_INVOCATION:
+ template: "The type argument(s) of the function '{0}' can't be inferred."
+ tip: "Use explicit type argument(s) for '{0}'."
+ comment: |-
+ When "strict-inference" is enabled, types in function invocations must be
+ inferred via the context type, or have type arguments.
+ INFERENCE_FAILURE_ON_FUNCTION_RETURN_TYPE:
+ template: "The return type of '{0}' cannot be inferred."
+ tip: "Declare the return type of '{0}'."
+ comment: |-
+ When "strict-inference" is enabled, recursive local functions, top-level
+ functions, methods, and function-typed function parameters must all
+ specify a return type. See the strict-inference resource:
+
+ https://github.com/dart-lang/language/blob/master/resources/type-system/strict-inference.md
+ INFERENCE_FAILURE_ON_GENERIC_INVOCATION:
+ template: "The type argument(s) of the generic function type '{0}' can't be inferred."
+ tip: "Use explicit type argument(s) for '{0}'."
+ comment: |-
+ When "strict-inference" is enabled, types in function invocations must be
+ inferred via the context type, or have type arguments.
+ INFERENCE_FAILURE_ON_INSTANCE_CREATION:
+ template: "The type argument(s) of the constructor '{0}' can't be inferred."
+ tip: "Use explicit type argument(s) for '{0}'."
+ comment: |-
+ When "strict-inference" is enabled, types in instance creation
+ (constructor calls) must be inferred via the context type, or have type
+ arguments.
+ INFERENCE_FAILURE_ON_UNINITIALIZED_VARIABLE:
+ template: "The type of {0} can't be inferred without either a type or initializer."
+ tip: Try specifying the type of the variable.
+ comment: |-
+ When "strict-inference" in enabled, uninitialized variables must be
+ declared with a specific type.
+ INFERENCE_FAILURE_ON_UNTYPED_PARAMETER:
+ template: "The type of {0} can't be inferred; a type must be explicitly provided."
+ tip: Try specifying the type of the parameter.
+ comment: |-
+ When "strict-inference" in enabled, function parameters must be
+ declared with a specific type, or inherit a type.
+ INVALID_ANNOTATION_TARGET:
+ template: "The annotation '{0}' can only be used on {1}"
+ comment: |-
+ Parameters:
+ 0: the name of the annotation
+ 1: the list of valid targets
+ INVALID_EXPORT_OF_INTERNAL_ELEMENT:
+ template: "The member '{0}' can't be exported as a part of a package's public API."
+ tip: "Try using a hide clause to hide '{0}'."
+ comment: |-
+ This hint is generated anywhere where an element annotated with `@internal`
+ is exported as a part of a package's public API.
+
+ Parameters:
+ 0: the name of the element
+ INVALID_EXPORT_OF_INTERNAL_ELEMENT_INDIRECTLY:
+ template: "The member '{0}' can't be exported as a part of a package's public API, but is indirectly exported as part of the signature of '{1}'."
+ tip: "Try using a hide clause to hide '{0}'."
+ comment: |-
+ This hint is generated anywhere where an element annotated with `@internal`
+ is exported indirectly as a part of a package's public API.
+
+ Parameters:
+ 0: the name of the element
+ INVALID_FACTORY_ANNOTATION:
+ template: Only methods can be annotated as factories.
+ comment: |-
+ This hint is generated anywhere a @factory annotation is associated with
+ anything other than a method.
+ INVALID_FACTORY_METHOD_DECL:
+ template: "Factory method '{0}' must have a return type."
+ comment: |-
+ This hint is generated anywhere a @factory annotation is associated with
+ a method that does not declare a return type.
+ INVALID_FACTORY_METHOD_IMPL:
+ template: "Factory method '{0}' doesn't return a newly allocated object."
+ comment: |-
+ This hint is generated anywhere a @factory annotation is associated with
+ a non-abstract method that can return anything other than a newly allocated
+ object.
+
+ Parameters:
+ 0: the name of the method
+ INVALID_IMMUTABLE_ANNOTATION:
+ template: Only classes can be annotated as being immutable.
+ comment: |-
+ This hint is generated anywhere an @immutable annotation is associated with
+ anything other than a class.
+ INVALID_INTERNAL_ANNOTATION:
+ template: "Only public elements in a package's private API can be annotated as being internal."
+ comment: |-
+ This hint is generated anywhere a @internal annotation is associated with
+ an element found in a package's public API.
+ INVALID_LANGUAGE_VERSION_OVERRIDE_GREATER:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: "The language version override can't specify a version greater than the latest known language version: {0}.{1}"
+ tip: Try removing the language version override.
+ INVALID_LANGUAGE_VERSION_OVERRIDE_AT_SIGN:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: "The Dart language version override number must begin with '@dart'"
+ tip: "Specify a Dart language version override with a comment like '// @dart = 2.0'."
+ comment: |-
+ Invalid Dart language version comments don't follow the specification [1].
+ If a comment begins with "@dart" or "dart" (letters in any case),
+ followed by optional whitespace, followed by optional non-alphanumeric,
+ non-whitespace characters, followed by optional whitespace, followed by
+ an optional alphabetical character, followed by a digit, then the
+ comment is considered to be an attempt at a language version override
+ comment. If this attempted language version override comment is not a
+ valid language version override comment, it is reported.
+
+ [1] https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/feature-specification.md#individual-library-language-version-override
+ INVALID_LANGUAGE_VERSION_OVERRIDE_LOCATION:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: The language version override must be before any declaration or directive.
+ tip: Try moving the language version override to the top of the file.
+ INVALID_LANGUAGE_VERSION_OVERRIDE_LOWER_CASE:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: "The Dart language version override comment must be specified with the word 'dart' in all lower case"
+ tip: "Specify a Dart language version override with a comment like '// @dart = 2.0'."
+ comment: |-
+ Invalid Dart language version comments don't follow the specification [1].
+ If a comment begins with "@dart" or "dart" (letters in any case),
+ followed by optional whitespace, followed by optional non-alphanumeric,
+ non-whitespace characters, followed by optional whitespace, followed by
+ an optional alphabetical character, followed by a digit, then the
+ comment is considered to be an attempt at a language version override
+ comment. If this attempted language version override comment is not a
+ valid language version override comment, it is reported.
+
+ [1] https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/feature-specification.md#individual-library-language-version-override
+ INVALID_LANGUAGE_VERSION_OVERRIDE_NUMBER:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: "The Dart language version override comment must be specified with a version number, like '2.0', after the '=' character."
+ tip: "Specify a Dart language version override with a comment like '// @dart = 2.0'."
+ comment: |-
+ Invalid Dart language version comments don't follow the specification [1].
+ If a comment begins with "@dart" or "dart" (letters in any case),
+ followed by optional whitespace, followed by optional non-alphanumeric,
+ non-whitespace characters, followed by optional whitespace, followed by
+ an optional alphabetical character, followed by a digit, then the
+ comment is considered to be an attempt at a language version override
+ comment. If this attempted language version override comment is not a
+ valid language version override comment, it is reported.
+
+ [1] https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/feature-specification.md#individual-library-language-version-override
+ INVALID_LANGUAGE_VERSION_OVERRIDE_PREFIX:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: "The Dart language version override number can't be prefixed with a letter"
+ tip: "Specify a Dart language version override with a comment like '// @dart = 2.0'."
+ comment: |-
+ Invalid Dart language version comments don't follow the specification [1].
+ If a comment begins with "@dart" or "dart" (letters in any case),
+ followed by optional whitespace, followed by optional non-alphanumeric,
+ non-whitespace characters, followed by optional whitespace, followed by
+ an optional alphabetical character, followed by a digit, then the
+ comment is considered to be an attempt at a language version override
+ comment. If this attempted language version override comment is not a
+ valid language version override comment, it is reported.
+
+ [1] https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/feature-specification.md#individual-library-language-version-override
+ INVALID_LANGUAGE_VERSION_OVERRIDE_TRAILING_CHARACTERS:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: "The Dart language version override comment can't be followed by any non-whitespace characters"
+ tip: "Specify a Dart language version override with a comment like '// @dart = 2.0'."
+ comment: |-
+ Invalid Dart language version comments don't follow the specification [1].
+ If a comment begins with "@dart" or "dart" (letters in any case),
+ followed by optional whitespace, followed by optional non-alphanumeric,
+ non-whitespace characters, followed by optional whitespace, followed by
+ an optional alphabetical character, followed by a digit, then the
+ comment is considered to be an attempt at a language version override
+ comment. If this attempted language version override comment is not a
+ valid language version override comment, it is reported.
+
+ [1] https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/feature-specification.md#individual-library-language-version-override
+ INVALID_LANGUAGE_VERSION_OVERRIDE_TWO_SLASHES:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: The Dart language version override comment must be specified with exactly two slashes.
+ tip: "Specify a Dart language version override with a comment like '// @dart = 2.0'."
+ comment: |-
+ Invalid Dart language version comments don't follow the specification [1].
+ If a comment begins with "@dart" or "dart" (letters in any case),
+ followed by optional whitespace, followed by optional non-alphanumeric,
+ non-whitespace characters, followed by optional whitespace, followed by
+ an optional alphabetical character, followed by a digit, then the
+ comment is considered to be an attempt at a language version override
+ comment. If this attempted language version override comment is not a
+ valid language version override comment, it is reported.
+
+ [1] https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/feature-specification.md#individual-library-language-version-override
+ INVALID_LANGUAGE_VERSION_OVERRIDE_EQUALS:
+ sharedName: INVALID_LANGUAGE_VERSION_OVERRIDE
+ template: "The Dart language version override comment must be specified with an '=' character"
+ tip: "Specify a Dart language version override with a comment like '// @dart = 2.0'."
+ comment: |-
+ Invalid Dart language version comments don't follow the specification [1].
+ If a comment begins with "@dart" or "dart" (letters in any case),
+ followed by optional whitespace, followed by optional non-alphanumeric,
+ non-whitespace characters, followed by optional whitespace, followed by
+ an optional alphabetical character, followed by a digit, then the
+ comment is considered to be an attempt at a language version override
+ comment. If this attempted language version override comment is not a
+ valid language version override comment, it is reported.
+
+ [1] https://github.com/dart-lang/language/blob/master/accepted/future-releases/language-versioning/feature-specification.md#individual-library-language-version-override
+ INVALID_LITERAL_ANNOTATION:
+ template: Only const constructors can have the `@literal` annotation.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the `@literal` annotation is
+ applied to anything other than a const constructor.
+
+ #### Examples
+
+ The following code produces this diagnostic because the constructor isn't
+ a `const` constructor:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class C {
+ [!@literal!]
+ C();
+ }
+ ```
+
+ The following code produces this diagnostic because `x` isn't a
+ constructor:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ [!@literal!]
+ var x;
+ ```
+
+ #### Common fixes
+
+ If the annotation is on a constructor and the constructor should always be
+ invoked with `const`, when possible, then mark the constructor with the
+ `const` keyword:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class C {
+ @literal
+ const C();
+ }
+ ```
+
+ If the constructor can't be marked as `const`, then remove the annotation.
+
+ If the annotation is on anything other than a constructor, then remove the
+ annotation:
+
+ ```dart
+ var x;
+ ```
+ INVALID_NON_VIRTUAL_ANNOTATION:
+ template: "The member '{0}' can't be '@nonVirtual' because it isn't a concrete instance member."
+ tip: Try removing @nonVirtual.
+ comment: |-
+ This hint is generated anywhere where `@nonVirtual` annotates something
+ other than a non-abstract instance member in a class or mixin.
+
+ Parameters:
+ 0: the name of the member
+ INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER:
+ template: "The member '{0}' is declared non-virtual in '{1}' and can't be overridden in subclasses."
+ comment: |-
+ This hint is generated anywhere where an instance member annotated with
+ `@nonVirtual` is overridden in a subclass.
+
+ Parameters:
+ 0: the name of the member
+ 1: the name of the defining class
+ INVALID_REQUIRED_NAMED_PARAM:
+ template: "The type parameter '{0}' is annotated with @required but only named parameters without a default value can be annotated with it."
+ tip: Remove @required.
+ comment: |-
+ This hint is generated anywhere where `@required` annotates a named
+ parameter with a default value.
+
+ Parameters:
+ 0: the name of the member
+ INVALID_REQUIRED_OPTIONAL_POSITIONAL_PARAM:
+ template: "Incorrect use of the annotation @required on the optional positional parameter '{0}'. Optional positional parameters cannot be required."
+ tip: Remove @required.
+ comment: |-
+ This hint is generated anywhere where `@required` annotates an optional
+ positional parameter.
+
+ Parameters:
+ 0: the name of the member
+ INVALID_REQUIRED_POSITIONAL_PARAM:
+ template: "Redundant use of the annotation @required on the required positional parameter '{0}'."
+ tip: Remove @required.
+ comment: |-
+ This hint is generated anywhere where `@required` annotates a non optional
+ positional parameter.
+
+ Parameters:
+ 0: the name of the member
+ RETURN_TYPE_INVALID_FOR_CATCH_ERROR:
+ sharedName: INVALID_RETURN_TYPE_FOR_CATCH_ERROR
+ template: "The return type '{0}' isn't assignable to '{1}', as required by 'Future.catchError'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the return type of the function
+ 1: the expected return type as defined by the type of the Future
+ RETURN_OF_INVALID_TYPE_FROM_CATCH_ERROR:
+ sharedName: INVALID_RETURN_TYPE_FOR_CATCH_ERROR
+ template: "A value of type '{0}' can't be returned by the 'onError' handler because it must be assignable to '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the return type as declared in the return statement
+ 1: the expected return type as defined by the type of the Future
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an invocation of
+ `Future.catchError` has an argument whose return type isn't compatible with
+ the type returned by the instance of `Future`. At runtime, the method
+ `catchError` attempts to return the value from the callback as the result
+ of the future, which results in another exception being thrown.
+
+ #### Example
+
+ The following code produces this diagnostic because `future` is declared to
+ return an `int` while `callback` is declared to return a `String`, and
+ `String` isn't a subtype of `int`:
+
+ ```dart
+ void f(Future<int> future, String Function(dynamic, StackTrace) callback) {
+ future.catchError([!callback!]);
+ }
+ ```
+
+ The following code produces this diagnostic because the closure being
+ passed to `catchError` returns an `int` while `future` is declared to
+ return a `String`:
+
+ ```dart
+ void f(Future<String> future) {
+ future.catchError((error, stackTrace) => [!3!]);
+ }
+ ```
+
+ #### Common fixes
+
+ If the instance of `Future` is declared correctly, then change the callback
+ to match:
+
+ ```dart
+ void f(Future<int> future, int Function(dynamic, StackTrace) callback) {
+ future.catchError(callback);
+ }
+ ```
+
+ If the declaration of the instance of `Future` is wrong, then change it to
+ match the callback:
+
+ ```dart
+ void f(Future<String> future, String Function(dynamic, StackTrace) callback) {
+ future.catchError(callback);
+ }
+ ```
+ INVALID_SEALED_ANNOTATION:
+ template: "The member '{0}' is annotated with '@sealed' but only classes can be annotated with it."
+ tip: Remove @sealed.
+ comment: |-
+ This hint is generated anywhere where `@sealed` annotates something other
+ than a class.
+
+ Parameters:
+ 0: the name of the member
+ INVALID_USE_OF_INTERNAL_MEMBER:
+ template: "The member '{0}' can only be used within its package."
+ comment: |-
+ This hint is generated anywhere where a member annotated with `@internal`
+ is used outside of the package in which it is declared.
+
+ Parameters:
+ 0: the name of the member
+ INVALID_USE_OF_PROTECTED_MEMBER:
+ template: "The member '{0}' can only be used within instance members of subclasses of '{1}'."
+ comment: |-
+ This hint is generated anywhere where a member annotated with `@protected`
+ is used outside of an instance member of a subclass.
+
+ Parameters:
+ 0: the name of the member
+ 1: the name of the defining class
+ INVALID_USE_OF_VISIBLE_FOR_OVERRIDING_MEMBER:
+ template: "The member '{0}' can only be used for overriding."
+ comment: |-
+ Parameters:
+ 0: the name of the member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an instance member that is
+ annotated with `visibleForOverriding` is referenced outside the library in
+ which it's declared for any reason other than to override it.
+
+ #### Example
+
+ Given a file named `a.dart` containing the following declaration:
+
+ ```dart
+ %uri="lib/a.dart"
+ import 'package:meta/meta.dart';
+
+ class A {
+ @visibleForOverriding
+ void a() {}
+ }
+ ```
+
+ The following code produces this diagnostic because the method `m` is being
+ invoked even though the only reason it's public is to allow it to be
+ overridden:
+
+ ```dart
+ import 'a.dart';
+
+ class B extends A {
+ void b() {
+ [!a!]();
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the invalid use of the member.
+ INVALID_USE_OF_VISIBLE_FOR_TEMPLATE_MEMBER:
+ template: "The member '{0}' can only be used within '{1}' or a template library."
+ comment: |-
+ This hint is generated anywhere where a member annotated with
+ `@visibleForTemplate` is used outside of a "template" Dart file.
+
+ Parameters:
+ 0: the name of the member
+ 1: the name of the defining class
+ INVALID_USE_OF_VISIBLE_FOR_TESTING_MEMBER:
+ template: "The member '{0}' can only be used within '{1}' or a test."
+ comment: |-
+ This hint is generated anywhere where a member annotated with
+ `@visibleForTesting` is used outside the defining library, or a test.
+
+ Parameters:
+ 0: the name of the member
+ 1: the name of the defining class
+ INVALID_VISIBILITY_ANNOTATION:
+ template: "The member '{0}' is annotated with '{1}', but this annotation is only meaningful on declarations of public members."
+ hasPublishedDocs: true
+ comment: |-
+ This hint is generated anywhere where a private declaration is annotated
+ with `@visibleForTemplate` or `@visibleForTesting`.
+
+ Parameters:
+ 0: the name of the member
+ 1: the name of the annotation
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when either the `@visibleForTemplate`
+ or `@visibleForTesting` annotation is applied to a non-public declaration.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ [!@visibleForTesting!]
+ void _someFunction() {}
+
+ void f() => _someFunction();
+ ```
+
+ #### Common fixes
+
+ If the declaration doesn't need to be used by test code, then remove the
+ annotation:
+
+ ```dart
+ void _someFunction() {}
+
+ void f() => _someFunction();
+ ```
+
+ If it does, then make it public:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ @visibleForTesting
+ void someFunction() {}
+
+ void f() => someFunction();
+ ```
+ INVALID_VISIBLE_FOR_OVERRIDING_ANNOTATION:
+ template: "The declaration '{0}' is annotated with 'visibleForOverriding'. Because '{0}' isn't an interface member that could be overridden, the annotation is meaningless."
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when anything other than a public
+ instance member of a class is annotated with `visibleForOverriding`.
+ Because only public instance members can be overridden outside the defining
+ library, there's no value to annotating any other declarations.
+
+ #### Example
+
+ The following code produces this diagnostic because the annotation is on a
+ class, and classes can't be overridden:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ [!@visibleForOverriding!]
+ class C {}
+ ```
+
+ #### Common fixes
+
+ Remove the annotation:
+
+ ```dart
+ class C {}
+ ```
+ MISSING_JS_LIB_ANNOTATION:
+ template: The @JS() annotation can only be used if it is also declared on the library directive.
+ tip: Try adding the annotation to the library directive.
+ comment: |-
+ Generate a hint for an element that is annotated with `@JS(...)` whose
+ library declaration is not similarly annotated.
+ MISSING_REQUIRED_PARAM:
+ template: "The parameter '{0}' is required."
+ hasPublishedDocs: true
+ comment: |-
+ Generate a hint for a constructor, function or method invocation where a
+ required parameter is missing.
+
+ Parameters:
+ 0: the name of the parameter
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method or function with a
+ named parameter that is annotated as being required is invoked without
+ providing a value for the parameter.
+
+ #### Examples
+
+ The following code produces this diagnostic because the named parameter `x`
+ is required:
+
+ ```dart
+ %language=2.9
+ import 'package:meta/meta.dart';
+
+ void f({@required int x}) {}
+
+ void g() {
+ [!f!]();
+ }
+ ```
+
+ #### Common fixes
+
+ Provide the required value:
+
+ ```dart
+ %language=2.9
+ import 'package:meta/meta.dart';
+
+ void f({@required int x}) {}
+
+ void g() {
+ f(x: 2);
+ }
+ ```
+ MISSING_REQUIRED_PARAM_WITH_DETAILS:
+ sharedName: MISSING_REQUIRED_PARAM
+ template: "The parameter '{0}' is required. {1}."
+ hasPublishedDocs: true
+ comment: |-
+ Generate a hint for a constructor, function or method invocation where a
+ required parameter is missing.
+
+ Parameters:
+ 0: the name of the parameter
+ 1: message details
+ MISSING_RETURN:
+ template: "This function has a return type of '{0}', but doesn't end with a return statement."
+ tip: "Try adding a return statement, or changing the return type to 'void'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the declared return type
+ documentation: |-
+ #### Description
+
+ Any function or method that doesn't end with either an explicit return or a
+ throw implicitly returns `null`. This is rarely the desired behavior. The
+ analyzer produces this diagnostic when it finds an implicit return.
+
+ #### Examples
+
+ The following code produces this diagnostic because `f` doesn't end with a
+ return:
+
+ ```dart
+ %language=2.9
+ int [!f!](int x) {
+ if (x < 0) {
+ return 0;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Add a `return` statement that makes the return value explicit, even if
+ `null` is the appropriate value.
+ MIXIN_ON_SEALED_CLASS:
+ template: "The class '{0}' shouldn't be used as a mixin constraint because it is sealed, and any class mixing in this mixin must have '{0}' as a superclass."
+ tip: Try composing with this class, or refer to its documentation for more information.
+ hasPublishedDocs: true
+ comment: |-
+ This hint is generated anywhere where a `@sealed` class is used as a
+ a superclass constraint of a mixin.
+
+ Parameters:
+ 0: the name of the sealed class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the superclass constraint of a
+ mixin is a class from a different package that was marked as `@sealed`.
+ Classes that are sealed can't be extended, implemented, mixed in, or used
+ as a superclass constraint.
+
+ #### Examples
+
+ If the package `p` defines a sealed class:
+
+ ```dart
+ %uri="package:p/p.dart"
+ import 'package:meta/meta.dart';
+
+ @sealed
+ class C {}
+ ```
+
+ Then, the following code, when in a package other than `p`, produces this
+ diagnostic:
+
+ ```dart
+ import 'package:p/p.dart';
+
+ [!mixin M on C {}!]
+ ```
+
+ #### Common fixes
+
+ If the classes that use the mixin don't need to be subclasses of the sealed
+ class, then consider adding a field and delegating to the wrapped instance
+ of the sealed class.
+ MUST_BE_IMMUTABLE:
+ template: "This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: {0}"
+ hasPublishedDocs: true
+ comment: |-
+ Generate a hint for classes that inherit from classes annotated with
+ `@immutable` but that are not immutable.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an immutable class defines one
+ or more instance fields that aren't final. A class is immutable if it's
+ marked as being immutable using the annotation `@immutable` or if it's a
+ subclass of an immutable class.
+
+ #### Examples
+
+ The following code produces this diagnostic because the field `x` isn't
+ final:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ @immutable
+ class [!C!] {
+ int x;
+
+ C(this.x);
+ }
+ ```
+
+ #### Common fixes
+
+ If instances of the class should be immutable, then add the keyword `final`
+ to all non-final field declarations:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ @immutable
+ class C {
+ final int x;
+
+ C(this.x);
+ }
+ ```
+
+ If the instances of the class should be mutable, then remove the
+ annotation, or choose a different superclass if the annotation is
+ inherited:
+
+ ```dart
+ class C {
+ int x;
+
+ C(this.x);
+ }
+ ```
+ MUST_CALL_SUPER:
+ template: "This method overrides a method annotated as '@mustCallSuper' in '{0}', but doesn't invoke the overridden method."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the class declaring the overridden method
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a method that overrides a method
+ that is annotated as `@mustCallSuper` doesn't invoke the overridden method
+ as required.
+
+ #### Examples
+
+ The following code produces this diagnostic because the method `m` in `B`
+ doesn't invoke the overridden method `m` in `A`:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class A {
+ @mustCallSuper
+ m() {}
+ }
+
+ class B extends A {
+ @override
+ [!m!]() {}
+ }
+ ```
+
+ #### Common fixes
+
+ Add an invocation of the overridden method in the overriding method:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class A {
+ @mustCallSuper
+ m() {}
+ }
+
+ class B extends A {
+ @override
+ m() {
+ super.m();
+ }
+ }
+ ```
+ NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR_USING_NEW:
+ sharedName: NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR
+ template: "This instance creation must be 'const', because the {0} constructor is marked as '@literal'."
+ tip: "Try replacing the 'new' keyword with 'const'."
+ hasPublishedDocs: true
+ comment: |-
+ Generate a hint for non-const instance creation (with the `new` keyword)
+ using a constructor annotated with `@literal`.
+
+ Parameters:
+ 0: the name of the class defining the annotated constructor
+ NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR:
+ template: "This instance creation must be 'const', because the {0} constructor is marked as '@literal'."
+ tip: "Try adding a 'const' keyword."
+ hasPublishedDocs: true
+ comment: |-
+ Generate a hint for non-const instance creation using a constructor
+ annotated with `@literal`.
+
+ Parameters:
+ 0: the name of the class defining the annotated constructor
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor that has the
+ `@literal` annotation is invoked without using the `const` keyword, but all
+ of the arguments to the constructor are constants. The annotation indicates
+ that the constructor should be used to create a constant value whenever
+ possible.
+
+ #### Examples
+
+ The following code produces this diagnostic:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class C {
+ @literal
+ const C();
+ }
+
+ C f() => [!C()!];
+ ```
+
+ #### Common fixes
+
+ Add the keyword `const` before the constructor invocation:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class C {
+ @literal
+ const C();
+ }
+
+ void f() => const C();
+ ```
+ NULLABLE_TYPE_IN_CATCH_CLAUSE:
+ template: "A potentially nullable type can't be used in an 'on' clause because it isn't valid to throw a nullable expression."
+ tip: Try using a non-nullable type.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the type following `on` in a
+ `catch` clause is a nullable type. It isn't valid to specify a nullable
+ type because it isn't possible to catch `null` (because it's a runtime
+ error to throw `null`).
+
+ #### Example
+
+ The following code produces this diagnostic because the exception type is
+ specified to allow `null` when `null` can't be thrown:
+
+ ```dart
+ void f() {
+ try {
+ // ...
+ } on [!FormatException?!] {
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the question mark from the type:
+
+ ```dart
+ void f() {
+ try {
+ // ...
+ } on FormatException {
+ }
+ }
+ ```
+ NULL_ARGUMENT_TO_NON_NULL_TYPE:
+ template: "'{0}' shouldn't be called with a null argument for the non-nullable type argument '{1}'."
+ tip: Try adding a non-null argument.
+ comment: |-
+ Parameters:
+ 0: the name of the method being invoked
+ 1: the type argument associated with the method
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when `null` is passed to either the
+ constructor `Future.value` or the method `Completer.complete` when the type
+ argument used to create the instance was non-nullable. Even though the type
+ system can't express this restriction, passing in a `null` results in a
+ runtime exception.
+
+ #### Example
+
+ The following code produces this diagnostic because `null` is being passed
+ to the constructor `Future.value` even though the type argument is the
+ non-nullable type `String`:
+
+ ```dart
+ Future<String> f() {
+ return Future.value([!null!]);
+ }
+ ```
+
+ #### Common fixes
+
+ Pass in a non-null value:
+
+ ```dart
+ Future<String> f() {
+ return Future.value('');
+ }
+ ```
+ NULL_AWARE_BEFORE_OPERATOR:
+ template: "The left operand uses '?.', so its value can be null."
+ comment: |-
+ When the left operand of a binary expression uses '?.' operator, it can be
+ `null`.
+ NULL_AWARE_IN_CONDITION:
+ template: "The value of the '?.' operator can be 'null', which isn't appropriate in a condition."
+ tip: "Try replacing the '?.' with a '.', testing the left-hand side for null if necessary."
+ comment: |-
+ A condition in a control flow statement could evaluate to `null` because it
+ uses the null-aware '?.' operator.
+ NULL_AWARE_IN_LOGICAL_OPERATOR:
+ template: "The value of the '?.' operator can be 'null', which isn't appropriate as an operand of a logical operator."
+ comment: |-
+ A condition in operands of a logical operator could evaluate to `null`
+ because it uses the null-aware '?.' operator.
+ NULL_CHECK_ALWAYS_FAILS:
+ template: "This null-check will always throw an exception because the expression will always evaluate to 'null'."
+ comment: |-
+ This hint indicates that a null literal is null-checked with `!`, but null
+ is never not null.
+ OVERRIDE_ON_NON_OVERRIDING_FIELD:
+ sharedName: OVERRIDE_ON_NON_OVERRIDING_MEMBER
+ template: "The field doesn't override an inherited getter or setter."
+ tip: Try updating this class to match the superclass, or removing the override annotation.
+ hasPublishedDocs: true
+ comment: |-
+ A field with the override annotation does not override a getter or setter.
+
+ No parameters.
+ OVERRIDE_ON_NON_OVERRIDING_GETTER:
+ sharedName: OVERRIDE_ON_NON_OVERRIDING_MEMBER
+ template: "The getter doesn't override an inherited getter."
+ tip: Try updating this class to match the superclass, or removing the override annotation.
+ hasPublishedDocs: true
+ comment: |-
+ A getter with the override annotation does not override an existing getter.
+
+ No parameters.
+ OVERRIDE_ON_NON_OVERRIDING_METHOD:
+ sharedName: OVERRIDE_ON_NON_OVERRIDING_MEMBER
+ template: "The method doesn't override an inherited method."
+ tip: Try updating this class to match the superclass, or removing the override annotation.
+ hasPublishedDocs: true
+ comment: |-
+ A method with the override annotation does not override an existing method.
+
+ No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a class member is annotated with
+ the `@override` annotation, but the member isn’t declared in any of the
+ supertypes of the class.
+
+ #### Examples
+
+ The following code produces this diagnostic because `m` isn't declared in
+ any of the supertypes of `C`:
+
+ ```dart
+ class C {
+ @override
+ String [!m!]() => '';
+ }
+ ```
+
+ #### Common fixes
+
+ If the member is intended to override a member with a different name, then
+ update the member to have the same name:
+
+ ```dart
+ class C {
+ @override
+ String toString() => '';
+ }
+ ```
+
+ If the member is intended to override a member that was removed from the
+ superclass, then consider removing the member from the subclass.
+
+ If the member can't be removed, then remove the annotation.
+ OVERRIDE_ON_NON_OVERRIDING_SETTER:
+ sharedName: OVERRIDE_ON_NON_OVERRIDING_MEMBER
+ template: "The setter doesn't override an inherited setter."
+ tip: Try updating this class to match the superclass, or removing the override annotation.
+ hasPublishedDocs: true
+ comment: |-
+ A setter with the override annotation does not override an existing setter.
+
+ No parameters.
+ PACKAGE_IMPORT_CONTAINS_DOT_DOT:
+ template: "A package import shouldn't contain '..'."
+ comment: |-
+ It is a bad practice for a package import to reference anything outside the
+ given package, or more generally, it is bad practice for a package import
+ to contain a "..". For example, a source file should not contain a
+ directive such as `import 'package:foo/../some.dart'`.
+ RECEIVER_OF_TYPE_NEVER:
+ template: "The receiver is of type 'Never', and will never complete with a value."
+ tip: Try checking for throw expressions or type errors in the receiver
+ comment: |-
+ It is not an error to call or tear-off a method, setter, or getter, or to
+ read or write a field, on a receiver of static type `Never`.
+ Implementations that provide feedback about dead or unreachable code are
+ encouraged to indicate that any arguments to the invocation are
+ unreachable.
+
+ It is not an error to apply an expression of type `Never` in the function
+ position of a function call. Implementations that provide feedback about
+ dead or unreachable code are encouraged to indicate that any arguments to
+ the call are unreachable.
+
+ Parameters: none
+ RETURN_OF_DO_NOT_STORE:
+ template: "'{0}' is annotated with 'doNotStore' and shouldn't be returned unless '{1}' is also annotated."
+ tip: "Annotate '{1}' with 'doNotStore'."
+ comment: |-
+ Users should not return values marked `@doNotStore` from functions,
+ methods or getters not marked `@doNotStore`.
+ SDK_VERSION_ASYNC_EXPORTED_FROM_CORE:
+ template: "The class '{0}' wasn't exported from 'dart:core' until version 2.1, but this code is required to be able to run on earlier versions."
+ tip: "Try either importing 'dart:async' or updating the SDK constraints."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when either the class `Future` or
+ `Stream` is referenced in a library that doesn't import `dart:async` in
+ code that has an SDK constraint whose lower bound is less than 2.1.0. In
+ earlier versions, these classes weren't defined in `dart:core`, so the
+ import was necessary.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.1.0:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.0.0 <2.4.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces this
+ diagnostic:
+
+ ```dart
+ void f([!Future!] f) {}
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the classes to be referenced:
+
+ ```yaml
+ environment:
+ sdk: '>=2.1.0 <2.4.0'
+ ```
+
+ If you need to support older versions of the SDK, then import the
+ `dart:async` library.
+
+ ```dart
+ import 'dart:async';
+
+ void f(Future f) {}
+ ```
+ SDK_VERSION_AS_EXPRESSION_IN_CONST_CONTEXT:
+ template: "The use of an as expression in a constant expression wasn't supported until version 2.3.2, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an `as` expression inside a
+ [constant context][] is found in code that has an SDK constraint whose
+ lower bound is less than 2.3.2. Using an `as` expression in a
+ [constant context][] wasn't supported in earlier versions, so this code
+ won't be able to run against earlier versions of the SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.3.2:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.1.0 <2.4.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces
+ this diagnostic:
+
+ ```dart
+ const num n = 3;
+ const int i = [!n as int!];
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the expression to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.3.2 <2.4.0'
+ ```
+
+ If you need to support older versions of the SDK, then either rewrite the
+ code to not use an `as` expression, or change the code so that the `as`
+ expression isn't in a [constant context][]:
+
+ ```dart
+ num x = 3;
+ int y = x as int;
+ ```
+ SDK_VERSION_BOOL_OPERATOR_IN_CONST_CONTEXT:
+ template: "The use of the operator '{0}' for 'bool' operands in a constant context wasn't supported until version 2.3.2, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when any use of the `&`, `|`, or `^`
+ operators on the class `bool` inside a [constant context][] is found in
+ code that has an SDK constraint whose lower bound is less than 2.3.2. Using
+ these operators in a [constant context][] wasn't supported in earlier
+ versions, so this code won't be able to run against earlier versions of the
+ SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.3.2:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.1.0 <2.4.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces this
+ diagnostic:
+
+ ```dart
+ const bool a = true;
+ const bool b = false;
+ const bool c = a [!&!] b;
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the operators to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.3.2 <2.4.0'
+ ```
+
+ If you need to support older versions of the SDK, then either rewrite the
+ code to not use these operators, or change the code so that the expression
+ isn't in a [constant context][]:
+
+ ```dart
+ const bool a = true;
+ const bool b = false;
+ bool c = a & b;
+ ```
+ SDK_VERSION_CONSTRUCTOR_TEAROFFS:
+ template: "Tearing off a constructor requires the 'constructor-tearoffs' language feature."
+ tip: "Try updating your pubspec.yaml to set the minimum SDK constraint to 2.15 or higher, and running 'pub get'."
+ comment: |-
+ No parameters.
+
+ There is also a [ParserError.EXPERIMENT_NOT_ENABLED] code which catches
+ some cases of constructor tearoff features (like `List<int>.filled;`).
+ Other constructor tearoff cases are not realized until resolution
+ (like `List.filled;`).
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor tear-off is found
+ in code that has an SDK constraint whose lower bound is less than 2.15.
+ Constructor tear-offs weren't supported in earlier versions, so this code
+ won't be able to run against earlier versions of the SDK.
+
+ #### Example
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.15:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.9.0 <2.15.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces this
+ diagnostic:
+
+ ```dart
+ %language=2.14
+ var setConstructor = [!Set.identity!];
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the operator to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.15.0 <2.16.0'
+ ```
+
+ If you need to support older versions of the SDK, then rewrite the code to
+ not use constructor tear-offs:
+
+ ```dart
+ %language=2.14
+ var setConstructor = () => Set.identity();
+ ```
+ SDK_VERSION_EQ_EQ_OPERATOR_IN_CONST_CONTEXT:
+ template: "Using the operator '==' for non-primitive types wasn't supported until version 2.3.2, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the operator `==` is used on a
+ non-primitive type inside a [constant context][] is found in code that has
+ an SDK constraint whose lower bound is less than 2.3.2. Using this operator
+ in a [constant context][] wasn't supported in earlier versions, so this
+ code won't be able to run against earlier versions of the SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.3.2:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.1.0 <2.4.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces this
+ diagnostic:
+
+ ```dart
+ %language=2.9
+ class C {}
+ const C a = null;
+ const C b = null;
+ const bool same = a [!==!] b;
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the operator to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.3.2 <2.4.0'
+ ```
+
+ If you need to support older versions of the SDK, then either rewrite the
+ code to not use the `==` operator, or change the code so that the
+ expression isn't in a [constant context][]:
+
+ ```dart
+ %language=2.9
+ class C {}
+ const C a = null;
+ const C b = null;
+ bool same = a == b;
+ ```
+ SDK_VERSION_EXTENSION_METHODS:
+ template: "Extension methods weren't supported until version 2.6.0, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an extension declaration or an
+ extension override is found in code that has an SDK constraint whose lower
+ bound is less than 2.6.0. Using extensions wasn't supported in earlier
+ versions, so this code won't be able to run against earlier versions of the
+ SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.6.0:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.4.0 <2.7.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces
+ this diagnostic:
+
+ ```dart
+ [!extension!] E on String {
+ void sayHello() {
+ print('Hello $this');
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the syntax to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.6.0 <2.7.0'
+ ```
+
+ If you need to support older versions of the SDK, then rewrite the code to
+ not make use of extensions. The most common way to do this is to rewrite
+ the members of the extension as top-level functions (or methods) that take
+ the value that would have been bound to `this` as a parameter:
+
+ ```dart
+ void sayHello(String s) {
+ print('Hello $s');
+ }
+ ```
+ SDK_VERSION_GT_GT_GT_OPERATOR:
+ template: "The operator '>>>' wasn't supported until version 2.14.0, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the operator `>>>` is used in
+ code that has an SDK constraint whose lower bound is less than 2.14.0. This
+ operator wasn't supported in earlier versions, so this code won't be able
+ to run against earlier versions of the SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.14.0:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.0.0 <2.15.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces this
+ diagnostic:
+
+ ```dart
+ int x = 3 [!>>>!] 4;
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the operator to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.14.0 <2.15.0'
+ ```
+
+ If you need to support older versions of the SDK, then rewrite the code to
+ not use the `>>>` operator:
+
+ ```dart
+ int x = logicalShiftRight(3, 4);
+
+ int logicalShiftRight(int leftOperand, int rightOperand) {
+ int divisor = 1 << rightOperand;
+ if (divisor == 0) {
+ return 0;
+ }
+ return leftOperand ~/ divisor;
+ }
+ ```
+ SDK_VERSION_IS_EXPRESSION_IN_CONST_CONTEXT:
+ template: "The use of an is expression in a constant context wasn't supported until version 2.3.2, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an `is` expression inside a
+ [constant context][] is found in code that has an SDK constraint whose
+ lower bound is less than 2.3.2. Using an `is` expression in a
+ [constant context][] wasn't supported in earlier versions, so this code
+ won't be able to run against earlier versions of the SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.3.2:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.1.0 <2.4.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces
+ this diagnostic:
+
+ ```dart
+ const Object x = 4;
+ const y = [!x is int!] ? 0 : 1;
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the expression to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.3.2 <2.4.0'
+ ```
+
+ If you need to support older versions of the SDK, then either rewrite the
+ code to not use the `is` operator, or, if that isn't possible, change the
+ code so that the `is` expression isn't in a
+ [constant context][]:
+
+ ```dart
+ const Object x = 4;
+ var y = x is int ? 0 : 1;
+ ```
+ SDK_VERSION_NEVER:
+ template: "The type 'Never' wasn't supported until version 2.12.0, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a reference to the class `Never`
+ is found in code that has an SDK constraint whose lower bound is less than
+ 2.12.0. This class wasn't defined in earlier versions, so this code won't
+ be able to run against earlier versions of the SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.12.0:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.5.0 <2.6.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces this
+ diagnostic:
+
+ ```dart
+ %language=2.9
+ [!Never!] n;
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the type to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.12.0 <2.13.0'
+ ```
+
+ If you need to support older versions of the SDK, then rewrite the code to
+ not reference this class:
+
+ ```dart
+ dynamic x;
+ ```
+ SDK_VERSION_SET_LITERAL:
+ template: "Set literals weren't supported until version 2.2, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a set literal is found in code
+ that has an SDK constraint whose lower bound is less than 2.2.0. Set
+ literals weren't supported in earlier versions, so this code won't be able
+ to run against earlier versions of the SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.2.0:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.1.0 <2.4.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces this
+ diagnostic:
+
+ ```dart
+ var s = [!<int>{}!];
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the syntax to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.2.0 <2.4.0'
+ ```
+
+ If you do need to support older versions of the SDK, then replace the set
+ literal with code that creates the set without the use of a literal:
+
+ ```dart
+ var s = new Set<int>();
+ ```
+ SDK_VERSION_UI_AS_CODE:
+ template: "The for, if, and spread elements weren't supported until version 2.3.0, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a for, if, or spread element is
+ found in code that has an SDK constraint whose lower bound is less than
+ 2.3.0. Using a for, if, or spread element wasn't supported in earlier
+ versions, so this code won't be able to run against earlier versions of the
+ SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.3.0:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.2.0 <2.4.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces
+ this diagnostic:
+
+ ```dart
+ var digits = [[!for (int i = 0; i < 10; i++) i!]];
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the syntax to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.3.0 <2.4.0'
+ ```
+
+ If you need to support older versions of the SDK, then rewrite the code to
+ not make use of those elements:
+
+ ```dart
+ var digits = _initializeDigits();
+
+ List<int> _initializeDigits() {
+ var digits = <int>[];
+ for (int i = 0; i < 10; i++) {
+ digits.add(i);
+ }
+ return digits;
+ }
+ ```
+ SDK_VERSION_UI_AS_CODE_IN_CONST_CONTEXT:
+ template: "The if and spread elements weren't supported in constant expressions until version 2.5.0, but this code is required to be able to run on earlier versions."
+ tip: Try updating the SDK constraints.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an if or spread element inside
+ a [constant context][] is found in code that has an SDK constraint whose
+ lower bound is less than 2.5.0. Using an if or spread element inside a
+ [constant context][] wasn't supported in earlier versions, so this code
+ won't be able to run against earlier versions of the SDK.
+
+ #### Examples
+
+ Here's an example of a pubspec that defines an SDK constraint with a lower
+ bound of less than 2.5.0:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ environment:
+ sdk: '>=2.4.0 <2.6.0'
+ ```
+
+ In the package that has that pubspec, code like the following produces
+ this diagnostic:
+
+ ```dart
+ const a = [1, 2];
+ const b = [[!...a!]];
+ ```
+
+ #### Common fixes
+
+ If you don't need to support older versions of the SDK, then you can
+ increase the SDK constraint to allow the syntax to be used:
+
+ ```yaml
+ environment:
+ sdk: '>=2.5.0 <2.6.0'
+ ```
+
+ If you need to support older versions of the SDK, then rewrite the code to
+ not make use of those elements:
+
+ ```dart
+ const a = [1, 2];
+ const b = [1, 2];
+ ```
+
+ If that isn't possible, change the code so that the element isn't in a
+ [constant context][]:
+
+ ```dart
+ const a = [1, 2];
+ var b = [...a];
+ ```
+ STRICT_RAW_TYPE:
+ template: "The generic type '{0}' should have explicit type arguments but doesn't."
+ tip: "Use explicit type arguments for '{0}'."
+ comment: |-
+ When "strict-raw-types" is enabled, "raw types" must have type arguments.
+
+ A "raw type" is a type name that does not use inference to fill in missing
+ type arguments; instead, each type argument is instantiated to its bound.
+ SUBTYPE_OF_SEALED_CLASS:
+ template: "The class '{0}' shouldn't be extended, mixed in, or implemented because it's sealed."
+ tip: "Try composing instead of inheriting, or refer to the documentation of '{0}' for more information."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the sealed class
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a sealed class (one that either
+ has the `@sealed` annotation or inherits or mixes in a sealed class) is
+ referenced in either the `extends`, `implements`, or `with` clause of a
+ class or mixin declaration if the declaration isn't in the same package as
+ the sealed class.
+
+ #### Example
+
+ Given a library in a package other than the package being analyzed that
+ contains the following:
+
+ ```dart
+ %uri="package:a/a.dart"
+ import 'package:meta/meta.dart';
+
+ class A {}
+
+ @sealed
+ class B {}
+ ```
+
+ The following code produces this diagnostic because `C`, which isn't in the
+ same package as `B`, is extending the sealed class `B`:
+
+ ```dart
+ import 'package:a/a.dart';
+
+ [!class C extends B {}!]
+ ```
+
+ #### Common fixes
+
+ If the class doesn't need to be a subtype of the sealed class, then change
+ the declaration so that it isn't:
+
+ ```dart
+ import 'package:a/a.dart';
+
+ class B extends A {}
+ ```
+
+ If the class needs to be a subtype of the sealed class, then either change
+ the sealed class so that it's no longer sealed or move the subclass into
+ the same package as the sealed class.
+ TYPE_CHECK_IS_NOT_NULL:
+ sharedName: TYPE_CHECK_WITH_NULL
+ template: "Tests for non-null should be done with '!= null'."
+ tip: "Try replacing the 'is! Null' check with '!= null'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when there's a type check (using the
+ `as` operator) where the type is `Null`. There's only one value whose type
+ is `Null`, so the code is both more readable and more performant when it
+ tests for `null` explicitly.
+
+ #### Example
+
+ The following code produces this diagnostic because the code is testing to
+ see whether the value of `s` is `null` by using a type check:
+
+ ```dart
+ void f(String? s) {
+ if ([!s is Null!]) {
+ return;
+ }
+ print(s);
+ }
+ ```
+
+ The following code produces this diagnostic because the code is testing to
+ see whether the value of `s` is something other than `null` by using a type
+ check:
+
+ ```dart
+ void f(String? s) {
+ if ([!s is! Null!]) {
+ print(s);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Replace the type check with the equivalent comparison with `null`:
+
+ ```dart
+ void f(String? s) {
+ if (s == null) {
+ return;
+ }
+ print(s);
+ }
+ ```
+ TYPE_CHECK_IS_NULL:
+ sharedName: TYPE_CHECK_WITH_NULL
+ template: "Tests for null should be done with '== null'."
+ tip: "Try replacing the 'is Null' check with '== null'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ UNDEFINED_HIDDEN_NAME:
+ template: "The library '{0}' doesn't export a member with the hidden name '{1}'."
+ tip: Try removing the name from the list of hidden members.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the library being imported
+ 1: the name in the hide clause that isn't defined in the library
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a hide combinator includes a
+ name that isn't defined by the library being imported.
+
+ #### Examples
+
+ The following code produces this diagnostic because `dart:math` doesn't
+ define the name `String`:
+
+ ```dart
+ import 'dart:math' hide [!String!], max;
+
+ var x = min(0, 1);
+ ```
+
+ #### Common fixes
+
+ If a different name should be hidden, then correct the name. Otherwise,
+ remove the name from the list:
+
+ ```dart
+ import 'dart:math' hide max;
+
+ var x = min(0, 1);
+ ```
+ UNDEFINED_REFERENCED_PARAMETER:
+ template: "The parameter '{0}' is not defined by '{1}'."
+ comment: |-
+ Parameters:
+ 0: the name of the undefined parameter
+ 1: the name of the targeted member
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an annotation of the form
+ `@UnusedResult.unless(parameterDefined: parameterName)` specifies a
+ parameter name that isn't defined by the annotated function.
+
+ #### Example
+
+ The following code produces this diagnostic because the function `f`
+ doesn't have a parameter named `b`:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ @UseResult.unless(parameterDefined: [!'b'!])
+ int f([int? a]) => a ?? 0;
+ ```
+
+ #### Common fixes
+
+ Change the argument named `parameterDefined` to match the name of one of
+ the parameters to the function:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ @UseResult.unless(parameterDefined: 'a')
+ int f([int? a]) => a ?? 0;
+ ```
+ UNDEFINED_SHOWN_NAME:
+ template: "The library '{0}' doesn't export a member with the shown name '{1}'."
+ tip: Try removing the name from the list of shown members.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the library being imported
+ 1: the name in the show clause that isn't defined in the library
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a show combinator includes a
+ name that isn't defined by the library being imported.
+
+ #### Examples
+
+ The following code produces this diagnostic because `dart:math` doesn't
+ define the name `String`:
+
+ ```dart
+ import 'dart:math' show min, [!String!];
+
+ var x = min(0, 1);
+ ```
+
+ #### Common fixes
+
+ If a different name should be shown, then correct the name. Otherwise,
+ remove the name from the list:
+
+ ```dart
+ import 'dart:math' show min;
+
+ var x = min(0, 1);
+ ```
+ UNIGNORABLE_IGNORE:
+ template: "The diagnostic '{0}' can't be ignored."
+ tip: Try removing the name from the list, or removing the whole comment if this is the only name in the list.
+ comment: |-
+ Parameters:
+ 0: the name of the non-diagnostic being ignored
+ UNNECESSARY_CAST:
+ template: Unnecessary cast.
+ tip: Try removing the cast.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the value being cast is already
+ known to be of the type that it's being cast to.
+
+ #### Examples
+
+ The following code produces this diagnostic because `n` is already known to
+ be an `int` as a result of the `is` test:
+
+ ```dart
+ void f(num n) {
+ if (n is int) {
+ ([!n as int!]).isEven;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the unnecessary cast:
+
+ ```dart
+ void f(num n) {
+ if (n is int) {
+ n.isEven;
+ }
+ }
+ ```
+ UNNECESSARY_IGNORE:
+ template: "The diagnostic '{0}' isn't produced at this location so it doesn't need to be ignored."
+ tip: Try removing the name from the list, or removing the whole comment if this is the only name in the list.
+ comment: |-
+ Parameters:
+ 0: the name of the diagnostic being ignored
+ UNNECESSARY_IMPORT:
+ template: "The import of '{0}' is unnecessary because all of the used elements are also provided by the import of '{1}'."
+ tip: Try removing the import directive.
+ comment: |-
+ Parameters:
+ 0: the uri that is not necessary
+ 1: the uri that makes it unnecessary
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an import isn't needed because
+ all of the names that are imported and referenced within the importing
+ library are also visible through another import.
+
+ #### Example
+
+ Given a file named `a.dart` that contains the following:
+
+ ```dart
+ %uri="lib/a.dart"
+ class A {}
+ ```
+
+ And, given a file named `b.dart` that contains the following:
+
+ ```dart
+ %uri="lib/b.dart"
+ export 'a.dart';
+
+ class B {}
+ ```
+
+ The following code produces this diagnostic because the class `A`, which is
+ imported from `a.dart`, is also imported from `b.dart`. Removing the import
+ of `a.dart` leaves the semantics unchanged:
+
+ ```dart
+ import [!'a.dart'!];
+ import 'b.dart';
+
+ void f(A a, B b) {}
+ ```
+
+ #### Common fixes
+
+ If the import isn't needed, then remove it.
+
+ If some of the names imported by this import are intended to be used but
+ aren't yet, and if those names aren't imported by other imports, then add
+ the missing references to those names.
+ UNNECESSARY_NO_SUCH_METHOD:
+ template: "Unnecessary 'noSuchMethod' declaration."
+ tip: "Try removing the declaration of 'noSuchMethod'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when there's a declaration of
+ `noSuchMethod`, the only thing the declaration does is invoke the
+ overridden declaration, and the overridden declaration isn't the
+ declaration in `Object`.
+
+ Overriding the implementation of `Object`'s `noSuchMethod` (no matter what
+ the implementation does) signals to the analyzer that it shouldn't flag any
+ inherited abstract methods that aren't implemented in that class. This
+ works even if the overriding implementation is inherited from a superclass,
+ so there's no value to declare it again in a subclass.
+
+ #### Example
+
+ The following code produces this diagnostic because the declaration of
+ `noSuchMethod` in `A` makes the declaration of `noSuchMethod` in `B`
+ unnecessary:
+
+ ```dart
+ class A {
+ @override
+ dynamic noSuchMethod(x) => super.noSuchMethod(x);
+ }
+ class B extends A {
+ @override
+ dynamic [!noSuchMethod!](y) {
+ return super.noSuchMethod(y);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the unnecessary declaration:
+
+ ```dart
+ class A {
+ @override
+ dynamic noSuchMethod(x) => super.noSuchMethod(x);
+ }
+ class B extends A {}
+ ```
+ UNNECESSARY_NULL_COMPARISON_FALSE:
+ sharedName: UNNECESSARY_NULL_COMPARISON
+ template: "The operand can't be null, so the condition is always false."
+ tip: Try removing the condition, an enclosing condition, or the whole conditional statement.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when it finds an equality comparison
+ (either `==` or `!=`) with one operand of `null` and the other operand
+ can't be `null`. Such comparisons are always either `true` or `false`, so
+ they serve no purpose.
+
+ #### Example
+
+ The following code produces this diagnostic because `x` can never be
+ `null`, so the comparison always evaluates to `true`:
+
+ ```dart
+ void f(int x) {
+ if (x [!!= null!]) {
+ print(x);
+ }
+ }
+ ```
+
+ The following code produces this diagnostic because `x` can never be
+ `null`, so the comparison always evaluates to `false`:
+
+ ```dart
+ void f(int x) {
+ if (x [!== null!]) {
+ throw ArgumentError("x can't be null");
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the other operand should be able to be `null`, then change the type of
+ the operand:
+
+ ```dart
+ void f(int? x) {
+ if (x != null) {
+ print(x);
+ }
+ }
+ ```
+
+ If the other operand really can't be `null`, then remove the condition:
+
+ ```dart
+ void f(int x) {
+ print(x);
+ }
+ ```
+ UNNECESSARY_NULL_COMPARISON_TRUE:
+ sharedName: UNNECESSARY_NULL_COMPARISON
+ template: "The operand can't be null, so the condition is always true."
+ tip: Remove the condition.
+ hasPublishedDocs: true
+ comment: No parameters.
+ UNNECESSARY_QUESTION_MARK:
+ template: "The '?' is unnecessary because '{0}' is nullable without it."
+ comment: |-
+ Parameters:
+ 0: the name of the type
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when either the type `dynamic` or the
+ type `Null` is followed by a question mark. Both of these types are
+ inherently nullable so the question mark doesn't change the semantics.
+
+ #### Example
+
+ The following code produces this diagnostic because the question mark
+ following `dynamic` isn't necessary:
+
+ ```dart
+ dynamic[!?!] x;
+ ```
+
+ #### Common fixes
+
+ Remove the unneeded question mark:
+
+ ```dart
+ dynamic x;
+ ```
+ UNNECESSARY_TYPE_CHECK_FALSE:
+ sharedName: UNNECESSARY_TYPE_CHECK
+ template: "Unnecessary type check; the result is always 'false'."
+ tip: Try correcting the type check, or removing the type check.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the value of a type check (using
+ either `is` or `is!`) is known at compile time.
+
+ #### Example
+
+ The following code produces this diagnostic because the test `a is Object?`
+ is always `true`:
+
+ ```dart
+ bool f<T>(T a) => [!a is Object?!];
+ ```
+
+ #### Common fixes
+
+ If the type check doesn't check what you intended to check, then change the
+ test:
+
+ ```dart
+ bool f<T>(T a) => a is Object;
+ ```
+
+ If the type check does check what you intended to check, then replace the
+ type check with its known value or completely remove it:
+
+ ```dart
+ bool f<T>(T a) => true;
+ ```
+ UNNECESSARY_TYPE_CHECK_TRUE:
+ sharedName: UNNECESSARY_TYPE_CHECK
+ template: "Unnecessary type check; the result is always 'true'."
+ tip: Try correcting the type check, or removing the type check.
+ hasPublishedDocs: true
+ comment: No parameters.
+ UNUSED_CATCH_CLAUSE:
+ template: "The exception variable '{0}' isn't used, so the 'catch' clause can be removed."
+ tip: Try removing the catch clause.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the exception variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `catch` clause is found, and
+ neither the exception parameter nor the optional stack trace parameter are
+ used in the `catch` block.
+
+ #### Examples
+
+ The following code produces this diagnostic because `e` isn't referenced:
+
+ ```dart
+ void f() {
+ try {
+ int.parse(';');
+ } on FormatException catch ([!e!]) {
+ // ignored
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the unused `catch` clause:
+
+ ```dart
+ void f() {
+ try {
+ int.parse(';');
+ } on FormatException {
+ // ignored
+ }
+ }
+ ```
+ UNUSED_CATCH_STACK:
+ template: "The stack trace variable '{0}' isn't used and can be removed."
+ tip: Try removing the stack trace variable, or using it.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the stack trace variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the stack trace parameter in a
+ `catch` clause isn't referenced within the body of the `catch` block.
+
+ #### Examples
+
+ The following code produces this diagnostic because `stackTrace` isn't
+ referenced:
+
+ ```dart
+ void f() {
+ try {
+ // ...
+ } catch (exception, [!stackTrace!]) {
+ // ...
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If you need to reference the stack trace parameter, then add a reference to
+ it. Otherwise, remove it:
+
+ ```dart
+ void f() {
+ try {
+ // ...
+ } catch (exception) {
+ // ...
+ }
+ }
+ ```
+ UNUSED_ELEMENT:
+ template: "The declaration '{0}' isn't referenced."
+ tip: "Try removing the declaration of '{0}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name that is declared but not referenced
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a private declaration isn't
+ referenced in the library that contains the declaration. The following
+ kinds of declarations are analyzed:
+ - Private top-level declarations, such as classes, enums, mixins, typedefs,
+ top-level variables, and top-level functions
+ - Private static and instance methods
+ - Optional parameters of private functions for which a value is never
+ passed, even when the parameter doesn't have a private name
+
+ #### Examples
+
+ Assuming that no code in the library references `_C`, the following code
+ produces this diagnostic:
+
+ ```dart
+ class [!_C!] {}
+ ```
+
+ Assuming that no code in the library passes a value for `y` in any
+ invocation of `_m`, the following code produces this diagnostic:
+
+ ```dart
+ %language=2.9
+ class C {
+ void _m(int x, [int [!y!]]) {}
+
+ void n() => _m(0);
+ }
+ ```
+
+ #### Common fixes
+
+ If the declaration isn't needed, then remove it:
+
+ ```dart
+ class C {
+ void _m(int x) {}
+
+ void n() => _m(0);
+ }
+ ```
+
+ If the declaration is intended to be used, then add the code to use it.
+ UNUSED_ELEMENT_PARAMETER:
+ sharedName: UNUSED_ELEMENT
+ template: "A value for optional parameter '{0}' isn't ever given."
+ tip: Try removing the unused parameter.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the parameter that is declared but not used
+ UNUSED_FIELD:
+ template: "The value of the field '{0}' isn't used."
+ tip: Try removing the field, or using it.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the unused field
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a private field is declared but
+ never read, even if it's written in one or more places.
+
+ #### Examples
+
+ The following code produces this diagnostic because the field
+ `_originalValue` isn't read anywhere in the library:
+
+ ```dart
+ class C {
+ final String [!_originalValue!];
+ final String _currentValue;
+
+ C(this._originalValue) : _currentValue = _originalValue;
+
+ String get value => _currentValue;
+ }
+ ```
+
+ It might appear that the field `_originalValue` is being read in the
+ initializer (`_currentValue = _originalValue`), but that is actually a
+ reference to the parameter of the same name, not a reference to the field.
+
+ #### Common fixes
+
+ If the field isn't needed, then remove it.
+
+ If the field was intended to be used, then add the missing code.
+ UNUSED_IMPORT:
+ template: "Unused import: '{0}'."
+ tip: Try removing the import directive.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the content of the unused import's uri
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an import isn't needed because
+ none of the names that are imported are referenced within the importing
+ library.
+
+ #### Examples
+
+ The following code produces this diagnostic because nothing defined in
+ `dart:async` is referenced in the library:
+
+ ```dart
+ import [!'dart:async'!];
+
+ void main() {}
+ ```
+
+ #### Common fixes
+
+ If the import isn't needed, then remove it.
+
+ If some of the imported names are intended to be used, then add the missing
+ code.
+ UNUSED_LABEL:
+ template: "The label '{0}' isn't used."
+ tip: "Try removing the label, or using it in either a 'break' or 'continue' statement."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the label that isn't used
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a label that isn't used is
+ found.
+
+ #### Examples
+
+ The following code produces this diagnostic because the label `loop` isn't
+ referenced anywhere in the method:
+
+ ```dart
+ void f(int limit) {
+ [!loop:!] for (int i = 0; i < limit; i++) {
+ print(i);
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the label isn't needed, then remove it:
+
+ ```dart
+ void f(int limit) {
+ for (int i = 0; i < limit; i++) {
+ print(i);
+ }
+ }
+ ```
+
+ If the label is needed, then use it:
+
+ ```dart
+ void f(int limit) {
+ loop: for (int i = 0; i < limit; i++) {
+ print(i);
+ break loop;
+ }
+ }
+ ```
+ TODO(brianwilkerson) Highlight the identifier without the colon.
+ UNUSED_LOCAL_VARIABLE:
+ template: "The value of the local variable '{0}' isn't used."
+ tip: Try removing the variable or using it.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the unused variable
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a local variable is declared but
+ never read, even if it's written in one or more places.
+
+ #### Examples
+
+ The following code produces this diagnostic because the value of `count` is
+ never read:
+
+ ```dart
+ void main() {
+ int [!count!] = 0;
+ }
+ ```
+
+ #### Common fixes
+
+ If the variable isn't needed, then remove it.
+
+ If the variable was intended to be used, then add the missing code.
+ UNUSED_RESULT:
+ template: "The value of '{0}' should be used."
+ tip: Try using the result by invoking a member, passing it to a function, or returning it from this function.
+ comment: |-
+ Parameters:
+ 0: the name of the annotated method, property or function
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a function annotated with
+ `useResult` is invoked, and the value returned by that function isn't used.
+ The value is considered to be used if a member of the value is invoked, if
+ the value is passed to another function, or if the value is assigned to a
+ variable or field.
+
+ #### Example
+
+ The following code produces this diagnostic because the invocation of
+ `c.a()` isn't used, even though the method `a` is annotated with
+ `useResult`:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class C {
+ @useResult
+ int a() => 0;
+
+ int b() => 0;
+ }
+
+ void f(C c) {
+ c.[!a!]();
+ }
+ ```
+
+ #### Common fixes
+
+ If you intended to invoke the annotated function, then use the value that
+ was returned:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class C {
+ @useResult
+ int a() => 0;
+
+ int b() => 0;
+ }
+
+ void f(C c) {
+ print(c.a());
+ }
+ ```
+
+ If you intended to invoke a different function, then correct the name of
+ the function being invoked:
+
+ ```dart
+ import 'package:meta/meta.dart';
+
+ class C {
+ @useResult
+ int a() => 0;
+
+ int b() => 0;
+ }
+
+ void f(C c) {
+ c.b();
+ }
+ ```
+ UNUSED_RESULT_WITH_MESSAGE:
+ sharedName: UNUSED_RESULT
+ template: "'{0}' should be used. {1}."
+ tip: Try using the result by invoking a member, passing it to a function, or returning it from this function.
+ comment: |-
+ The result of invoking a method, property, or function annotated with
+ `@useResult` must be used (assigned, passed to a function as an argument,
+ or returned by a function).
+
+ Parameters:
+ 0: the name of the annotated method, property or function
+ 1: message details
+ UNUSED_SHOWN_NAME:
+ template: "The name {0} is shown, but isn’t used."
+ tip: Try removing the name from the list of shown members.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name that is shown but not used
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a show combinator includes a
+ name that isn't used within the library. Because it isn't referenced, the
+ name can be removed.
+
+ #### Examples
+
+ The following code produces this diagnostic because the function `max`
+ isn't used:
+
+ ```dart
+ import 'dart:math' show min, [!max!];
+
+ var x = min(0, 1);
+ ```
+
+ #### Common fixes
+
+ Either use the name or remove it:
+
+ ```dart
+ import 'dart:math' show min;
+
+ var x = min(0, 1);
+ ```
+ USE_OF_NATIVE_EXTENSION:
+ template: Dart native extensions are deprecated and aren’t available in Dart 2.15.
+ tip: "Try using dart:ffi for C interop."
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a library is imported using the
+ `dart-ext` scheme.
+
+ #### Example
+
+ The following code produces this diagnostic because the native library `x`
+ is being imported using a scheme of `dart-ext`:
+
+ ```dart
+ [!import 'dart-ext:x';!]
+ int f() native 'string';
+ ```
+
+ #### Common fixes
+
+ Rewrite the code to use `dart:ffi` as a way of invoking the contents of the
+ native library.
+LanguageCode:
+ IMPLICIT_DYNAMIC_FIELD:
+ template: "Missing field type for '{0}'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_FUNCTION:
+ template: "Missing type arguments for generic function '{0}<{1}>'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_INVOKE:
+ template: "Missing type arguments for calling generic function type '{0}'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_LIST_LITERAL:
+ template: Missing type argument for list literal.
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_MAP_LITERAL:
+ template: Missing type arguments for map literal.
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_METHOD:
+ template: "Missing type arguments for generic method '{0}<{1}>'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_PARAMETER:
+ template: "Missing parameter type for '{0}'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_RETURN:
+ template: "Missing return type for '{0}'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_TYPE:
+ template: "Missing type arguments for generic type '{0}'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ IMPLICIT_DYNAMIC_VARIABLE:
+ template: "Missing variable type for '{0}'."
+ tip: Try adding an explicit type, or remove implicit-dynamic from your analysis options file.
+ManifestWarningCode:
+ CAMERA_PERMISSIONS_INCOMPATIBLE:
+ template: Camera permissions make app incompatible for Chrome OS, consider adding optional features "android.hardware.camera" and "android.hardware.camera.autofocus".
+ tip: "Try adding `<uses-feature android:name=\"android.hardware.camera\" android:required=\"false\">` `<uses-feature android:name=\"android.hardware.camera.autofocus\" android:required=\"false\">`."
+ comment: |-
+ A code indicating that the camera permissions is not supported on Chrome
+ OS.
+ NON_RESIZABLE_ACTIVITY:
+ template: The `<activity>` element should be allowed to be resized to allow users to take advantage of the multi-window environment on Chrome OS
+ tip: Consider declaring the corresponding activity element with `resizableActivity="true"` attribute.
+ comment: A code indicating that the activity is set to be non resizable.
+ NO_TOUCHSCREEN_FEATURE:
+ template: "The default \"android.hardware.touchscreen\" needs to be optional for Chrome OS. "
+ tip: "Consider adding <uses-feature android:name=\"android.hardware.touchscreen\" android:required=\"false\" /> to the manifest."
+ comment: |-
+ A code indicating that the touchscreen feature is not specified in the
+ manifest.
+ PERMISSION_IMPLIES_UNSUPPORTED_HARDWARE:
+ template: "Permission makes app incompatible for Chrome OS, consider adding optional {0} feature tag, "
+ tip: " Try adding `<uses-feature android:name=\"{0}\" android:required=\"false\">`."
+ comment: |-
+ A code indicating that a specified permission is not supported on Chrome
+ OS.
+ SETTING_ORIENTATION_ON_ACTIVITY:
+ template: The `<activity>` element should not be locked to any orientation so that users can take advantage of the multi-window environments and larger screens on Chrome OS
+ tip: Consider declaring the corresponding activity element with `screenOrientation="unspecified"` or `"fullSensor"` attribute.
+ comment: A code indicating that the activity is locked to an orientation.
+ UNSUPPORTED_CHROME_OS_FEATURE:
+ template: "The feature {0} is not supported on Chrome OS, consider making it optional."
+ tip: "Try changing to `android:required=\"false\"` for this feature."
+ comment: A code indicating that a specified feature is not supported on Chrome OS.
+ UNSUPPORTED_CHROME_OS_HARDWARE:
+ template: "The feature {0} is not supported on Chrome OS, consider making it optional."
+ tip: "Try adding `android:required=\"false\"` for this feature."
+ comment: |-
+ A code indicating that a specified hardware feature is not supported on
+ Chrome OS.
+ParserErrorCode:
+ ABSTRACT_CLASS_MEMBER:
+ copyFromCfe: true
+ ABSTRACT_ENUM:
+ template: "Enums can't be declared to be 'abstract'."
+ tip: "Try removing the keyword 'abstract'."
+ ABSTRACT_EXTERNAL_FIELD:
+ copyFromCfe: true
+ ABSTRACT_LATE_FIELD:
+ copyFromCfe: true
+ ABSTRACT_STATIC_FIELD:
+ copyFromCfe: true
+ ABSTRACT_STATIC_METHOD:
+ template: "Static methods can't be declared to be 'abstract'."
+ tip: "Try removing the keyword 'abstract'."
+ ABSTRACT_TOP_LEVEL_FUNCTION:
+ template: "Top-level functions can't be declared to be 'abstract'."
+ tip: "Try removing the keyword 'abstract'."
+ ABSTRACT_TOP_LEVEL_VARIABLE:
+ template: "Top-level variables can't be declared to be 'abstract'."
+ tip: "Try removing the keyword 'abstract'."
+ ABSTRACT_TYPEDEF:
+ template: "Typedefs can't be declared to be 'abstract'."
+ tip: "Try removing the keyword 'abstract'."
+ ANNOTATION_ON_TYPE_ARGUMENT:
+ copyFromCfe: true
+ ANNOTATION_WITH_TYPE_ARGUMENTS:
+ copyFromCfe: true
+ ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED:
+ copyFromCfe: true
+ ASYNC_KEYWORD_USED_AS_IDENTIFIER:
+ template: "The keywords 'await' and 'yield' can't be used as identifiers in an asynchronous or generator function."
+ comment: |-
+ 16.32 Identifier Reference: It is a compile-time error if any of the
+ identifiers async, await, or yield is used as an identifier in a function
+ body marked with either async, async, or sync.
+ BINARY_OPERATOR_WRITTEN_OUT:
+ copyFromCfe: true
+ BREAK_OUTSIDE_OF_LOOP:
+ copyFromCfe: true
+ CATCH_SYNTAX:
+ copyFromCfe: true
+ CATCH_SYNTAX_EXTRA_PARAMETERS:
+ copyFromCfe: true
+ CLASS_IN_CLASS:
+ copyFromCfe: true
+ COLON_IN_PLACE_OF_IN:
+ copyFromCfe: true
+ CONFLICTING_MODIFIERS:
+ copyFromCfe: true
+ CONSTRUCTOR_WITH_RETURN_TYPE:
+ copyFromCfe: true
+ CONSTRUCTOR_WITH_TYPE_ARGUMENTS:
+ copyFromCfe: true
+ CONST_AND_FINAL:
+ copyFromCfe: true
+ CONST_CLASS:
+ copyFromCfe: true
+ CONST_CONSTRUCTOR_WITH_BODY:
+ template: "Const constructors can't have a body."
+ tip: "Try removing either the 'const' keyword or the body."
+ CONST_ENUM:
+ template: "Enums can't be declared to be 'const'."
+ tip: "Try removing the 'const' keyword."
+ CONST_FACTORY:
+ copyFromCfe: true
+ CONST_METHOD:
+ copyFromCfe: true
+ CONST_TYPEDEF:
+ template: "Type aliases can't be declared to be 'const'."
+ tip: "Try removing the 'const' keyword."
+ CONTINUE_OUTSIDE_OF_LOOP:
+ copyFromCfe: true
+ CONTINUE_WITHOUT_LABEL_IN_CASE:
+ copyFromCfe: true
+ COVARIANT_AND_STATIC:
+ copyFromCfe: true
+ COVARIANT_CONSTRUCTOR:
+ template: "A constructor can't be declared to be 'covariant'."
+ tip: "Try removing the keyword 'covariant'."
+ COVARIANT_MEMBER:
+ copyFromCfe: true
+ COVARIANT_TOP_LEVEL_DECLARATION:
+ template: "Top-level declarations can't be declared to be covariant."
+ tip: "Try removing the keyword 'covariant'."
+ DEFAULT_VALUE_IN_FUNCTION_TYPE:
+ template: "Parameters in a function type can't have default values."
+ tip: Try removing the default value.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a function type associated with
+ a parameter includes optional parameters that have a default value. This
+ isn't allowed because the default values of parameters aren't part of the
+ function's type, and therefore including them doesn't provide any value.
+
+ #### Example
+
+ The following code produces this diagnostic because the parameter `p` has a
+ default value even though it's part of the type of the parameter `g`:
+
+ ```dart
+ void f(void Function([int p [!=!] 0]) g) {
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the default value from the function-type's parameter:
+
+ ```dart
+ void f(void Function([int p]) g) {
+ }
+ ```
+ DEFERRED_AFTER_PREFIX:
+ copyFromCfe: true
+ DIRECTIVE_AFTER_DECLARATION:
+ copyFromCfe: true
+ DUPLICATED_MODIFIER:
+ copyFromCfe: true
+ comment: |-
+ Parameters:
+ 0: the modifier that was duplicated
+ DUPLICATE_DEFERRED:
+ copyFromCfe: true
+ DUPLICATE_LABEL_IN_SWITCH_STATEMENT:
+ copyFromCfe: true
+ comment: |-
+ Parameters:
+ 0: the label that was duplicated
+ DUPLICATE_PREFIX:
+ copyFromCfe: true
+ EMPTY_ENUM_BODY:
+ template: An enum must declare at least one constant name.
+ tip: Try declaring a constant.
+ ENUM_IN_CLASS:
+ copyFromCfe: true
+ EQUALITY_CANNOT_BE_EQUALITY_OPERAND:
+ copyFromCfe: true
+ EXPECTED_BODY:
+ copyFromCfe: true
+ EXPECTED_CASE_OR_DEFAULT:
+ template: "Expected 'case' or 'default'."
+ tip: Try placing this code inside a case clause.
+ EXPECTED_CLASS_MEMBER:
+ template: Expected a class member.
+ tip: Try placing this code inside a class member.
+ EXPECTED_ELSE_OR_COMMA:
+ copyFromCfe: true
+ EXPECTED_EXECUTABLE:
+ template: Expected a method, getter, setter or operator declaration.
+ tip: This appears to be incomplete code. Try removing it or completing it.
+ EXPECTED_IDENTIFIER_BUT_GOT_KEYWORD:
+ copyFromCfe: true
+ EXPECTED_INSTEAD:
+ copyFromCfe: true
+ EXPECTED_LIST_OR_MAP_LITERAL:
+ template: Expected a list or map literal.
+ tip: Try inserting a list or map literal, or remove the type arguments.
+ EXPECTED_STRING_LITERAL:
+ template: Expected a string literal.
+ EXPECTED_TOKEN:
+ template: "Expected to find '{0}'."
+ comment: |-
+ Parameters:
+ 0: the token that was expected but not found
+ EXPECTED_TYPE_NAME:
+ template: Expected a type name.
+ EXPERIMENT_NOT_ENABLED:
+ copyFromCfe: true
+ EXPORT_DIRECTIVE_AFTER_PART_DIRECTIVE:
+ copyFromCfe: true
+ EXTENSION_DECLARES_ABSTRACT_MEMBER:
+ copyFromCfe: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an abstract declaration is
+ declared in an extension. Extensions can declare only concrete members.
+
+ #### Examples
+
+ The following code produces this diagnostic because the method `a` doesn't
+ have a body:
+
+ ```dart
+ extension E on String {
+ int [!a!]();
+ }
+ ```
+
+ #### Common fixes
+
+ Either provide an implementation for the member or remove it.
+ EXTENSION_DECLARES_CONSTRUCTOR:
+ copyFromCfe: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a constructor declaration is
+ found in an extension. It isn't valid to define a constructor because
+ extensions aren't classes, and it isn't possible to create an instance of
+ an extension.
+
+ #### Examples
+
+ The following code produces this diagnostic because there is a constructor
+ declaration in `E`:
+
+ ```dart
+ extension E on String {
+ [!E!]() : super();
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the constructor or replace it with a static method.
+ EXTENSION_DECLARES_INSTANCE_FIELD:
+ copyFromCfe: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an instance field declaration is
+ found in an extension. It isn't valid to define an instance field because
+ extensions can only add behavior, not state.
+
+ #### Examples
+
+ The following code produces this diagnostic because `s` is an instance
+ field:
+
+ ```dart
+ %language=2.9
+ extension E on String {
+ String [!s!];
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the field, make it a static field, or convert it to be a getter,
+ setter, or method.
+ EXTERNAL_CLASS:
+ copyFromCfe: true
+ EXTERNAL_CONSTRUCTOR_WITH_BODY:
+ copyFromCfe: true
+ EXTERNAL_CONSTRUCTOR_WITH_INITIALIZER:
+ copyFromCfe: true
+ EXTERNAL_ENUM:
+ copyFromCfe: true
+ EXTERNAL_FACTORY_REDIRECTION:
+ copyFromCfe: true
+ EXTERNAL_FACTORY_WITH_BODY:
+ copyFromCfe: true
+ EXTERNAL_FIELD:
+ copyFromCfe: true
+ EXTERNAL_GETTER_WITH_BODY:
+ template: "External getters can't have a body."
+ tip: "Try removing the body of the getter, or removing the keyword 'external'."
+ EXTERNAL_LATE_FIELD:
+ copyFromCfe: true
+ EXTERNAL_METHOD_WITH_BODY:
+ copyFromCfe: true
+ EXTERNAL_OPERATOR_WITH_BODY:
+ template: "External operators can't have a body."
+ tip: "Try removing the body of the operator, or removing the keyword 'external'."
+ EXTERNAL_SETTER_WITH_BODY:
+ template: "External setters can't have a body."
+ tip: "Try removing the body of the setter, or removing the keyword 'external'."
+ EXTERNAL_TYPEDEF:
+ copyFromCfe: true
+ EXTRANEOUS_MODIFIER:
+ copyFromCfe: true
+ FACTORY_TOP_LEVEL_DECLARATION:
+ copyFromCfe: true
+ FACTORY_WITHOUT_BODY:
+ template: "A non-redirecting 'factory' constructor must have a body."
+ tip: Try adding a body to the constructor.
+ FACTORY_WITH_INITIALIZERS:
+ template: "A 'factory' constructor can't have initializers."
+ tip: "Try removing the 'factory' keyword to make this a generative constructor, or removing the initializers."
+ FIELD_INITIALIZED_OUTSIDE_DECLARING_CLASS:
+ copyFromCfe: true
+ FIELD_INITIALIZER_OUTSIDE_CONSTRUCTOR:
+ copyFromCfe: true
+ FINAL_AND_COVARIANT:
+ copyFromCfe: true
+ FINAL_AND_COVARIANT_LATE_WITH_INITIALIZER:
+ copyFromCfe: true
+ FINAL_AND_VAR:
+ copyFromCfe: true
+ FINAL_CLASS:
+ template: "Classes can't be declared to be 'final'."
+ tip: "Try removing the keyword 'final'."
+ FINAL_CONSTRUCTOR:
+ template: "A constructor can't be declared to be 'final'."
+ tip: "Try removing the keyword 'final'."
+ FINAL_ENUM:
+ template: "Enums can't be declared to be 'final'."
+ tip: "Try removing the keyword 'final'."
+ FINAL_METHOD:
+ template: "Getters, setters and methods can't be declared to be 'final'."
+ tip: "Try removing the keyword 'final'."
+ FINAL_TYPEDEF:
+ template: "Typedefs can't be declared to be 'final'."
+ tip: "Try removing the keyword 'final'."
+ FUNCTION_TYPED_PARAMETER_VAR:
+ template: "Function-typed parameters can't specify 'const', 'final' or 'var' in place of a return type."
+ tip: Try replacing the keyword with a return type.
+ GETTER_CONSTRUCTOR:
+ copyFromCfe: true
+ GETTER_IN_FUNCTION:
+ template: "Getters can't be defined within methods or functions."
+ tip: Try moving the getter outside the method or function, or converting the getter to a function.
+ GETTER_WITH_PARAMETERS:
+ template: Getters must be declared without a parameter list.
+ tip: "Try removing the parameter list, or removing the keyword 'get' to define a method rather than a getter."
+ ILLEGAL_ASSIGNMENT_TO_NON_ASSIGNABLE:
+ copyFromCfe: true
+ IMPLEMENTS_BEFORE_EXTENDS:
+ copyFromCfe: true
+ IMPLEMENTS_BEFORE_ON:
+ copyFromCfe: true
+ IMPLEMENTS_BEFORE_WITH:
+ copyFromCfe: true
+ IMPORT_DIRECTIVE_AFTER_PART_DIRECTIVE:
+ copyFromCfe: true
+ INITIALIZED_VARIABLE_IN_FOR_EACH:
+ copyFromCfe: true
+ INVALID_AWAIT_IN_FOR:
+ copyFromCfe: true
+ INVALID_CODE_POINT:
+ template: "The escape sequence '{0}' isn't a valid code point."
+ comment: |-
+ Parameters:
+ 0: the invalid escape sequence
+ INVALID_COMMENT_REFERENCE:
+ template: "Comment references should contain a possibly prefixed identifier and can start with 'new', but shouldn't contain anything else."
+ INVALID_CONSTRUCTOR_NAME:
+ copyFromCfe: true
+ INVALID_GENERIC_FUNCTION_TYPE:
+ template: Invalid generic function type.
+ tip: "Try using a generic function type (returnType 'Function(' parameters ')')."
+ INVALID_HEX_ESCAPE:
+ copyFromCfe: true
+ INVALID_INITIALIZER:
+ copyFromCfe: true
+ INVALID_LITERAL_IN_CONFIGURATION:
+ template: "The literal in a configuration can't contain interpolation."
+ tip: Try removing the interpolation expressions.
+ INVALID_OPERATOR:
+ copyFromCfe: true
+ comment: |-
+ Parameters:
+ 0: the operator that is invalid
+ INVALID_OPERATOR_FOR_SUPER:
+ template: "The operator '{0}' can't be used with 'super'."
+ comment: |-
+ Parameters:
+ 0: the operator being applied to 'super'
+
+ Only generated by the old parser.
+ Replaced by INVALID_OPERATOR_QUESTIONMARK_PERIOD_FOR_SUPER.
+ INVALID_OPERATOR_QUESTIONMARK_PERIOD_FOR_SUPER:
+ copyFromCfe: true
+ INVALID_STAR_AFTER_ASYNC:
+ template: "The modifier 'async*' isn't allowed for an expression function body."
+ tip: Try converting the body to a block.
+ INVALID_SUPER_IN_INITIALIZER:
+ copyFromCfe: true
+ INVALID_SYNC:
+ template: "The modifier 'sync' isn't allowed for an expression function body."
+ tip: Try converting the body to a block.
+ INVALID_THIS_IN_INITIALIZER:
+ copyFromCfe: true
+ INVALID_UNICODE_ESCAPE:
+ copyFromCfe: true
+ INVALID_USE_OF_COVARIANT_IN_EXTENSION:
+ copyFromCfe: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a member declared inside an
+ extension uses the keyword `covariant` in the declaration of a parameter.
+ Extensions aren't classes and don't have subclasses, so the keyword serves
+ no purpose.
+
+ #### Examples
+
+ The following code produces this diagnostic because `i` is marked as being
+ covariant:
+
+ ```dart
+ extension E on String {
+ void a([!covariant!] int i) {}
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the `covariant` keyword:
+
+ ```dart
+ extension E on String {
+ void a(int i) {}
+ }
+ ```
+ LIBRARY_DIRECTIVE_NOT_FIRST:
+ copyFromCfe: true
+ LITERAL_WITH_CLASS:
+ copyFromCfe: true
+ LITERAL_WITH_CLASS_AND_NEW:
+ copyFromCfe: true
+ LITERAL_WITH_NEW:
+ copyFromCfe: true
+ LOCAL_FUNCTION_DECLARATION_MODIFIER:
+ template: "Local function declarations can't specify any modifiers."
+ tip: Try removing the modifier.
+ MEMBER_WITH_CLASS_NAME:
+ copyFromCfe: true
+ MISSING_ASSIGNABLE_SELECTOR:
+ copyFromCfe: true
+ MISSING_ASSIGNMENT_IN_INITIALIZER:
+ copyFromCfe: true
+ MISSING_CATCH_OR_FINALLY:
+ copyFromCfe: true
+ MISSING_CLOSING_PARENTHESIS:
+ template: The closing parenthesis is missing.
+ tip: Try adding the closing parenthesis.
+ MISSING_CONST_FINAL_VAR_OR_TYPE:
+ copyFromCfe: true
+ MISSING_ENUM_BODY:
+ template: An enum definition must have a body with at least one constant name.
+ tip: Try adding a body and defining at least one constant.
+ MISSING_EXPRESSION_IN_INITIALIZER:
+ template: Expected an expression after the assignment operator.
+ tip: Try adding the value to be assigned, or remove the assignment operator.
+ MISSING_EXPRESSION_IN_THROW:
+ copyFromCfe: true
+ MISSING_FUNCTION_BODY:
+ template: A function body must be provided.
+ tip: Try adding a function body.
+ MISSING_FUNCTION_KEYWORD:
+ template: "Function types must have the keyword 'Function' before the parameter list."
+ tip: "Try adding the keyword 'Function'."
+ MISSING_FUNCTION_PARAMETERS:
+ template: Functions must have an explicit list of parameters.
+ tip: Try adding a parameter list.
+ MISSING_GET:
+ template: "Getters must have the keyword 'get' before the getter name."
+ tip: "Try adding the keyword 'get'."
+ MISSING_IDENTIFIER:
+ template: Expected an identifier.
+ MISSING_INITIALIZER:
+ copyFromCfe: true
+ MISSING_KEYWORD_OPERATOR:
+ copyFromCfe: true
+ MISSING_METHOD_PARAMETERS:
+ template: Methods must have an explicit list of parameters.
+ tip: Try adding a parameter list.
+ MISSING_NAME_FOR_NAMED_PARAMETER:
+ template: Named parameters in a function type must have a name
+ tip: Try providing a name for the parameter or removing the curly braces.
+ MISSING_NAME_IN_LIBRARY_DIRECTIVE:
+ template: Library directives must include a library name.
+ tip: "Try adding a library name after the keyword 'library', or remove the library directive if the library doesn't have any parts."
+ MISSING_NAME_IN_PART_OF_DIRECTIVE:
+ template: Part-of directives must include a library name.
+ tip: "Try adding a library name after the 'of'."
+ MISSING_PREFIX_IN_DEFERRED_IMPORT:
+ copyFromCfe: true
+ MISSING_STAR_AFTER_SYNC:
+ template: "The modifier 'sync' must be followed by a star ('*')."
+ tip: Try removing the modifier, or add a star.
+ MISSING_STATEMENT:
+ copyFromCfe: true
+ MISSING_TERMINATOR_FOR_PARAMETER_GROUP:
+ template: "There is no '{0}' to close the parameter group."
+ tip: "Try inserting a '{0}' at the end of the group."
+ comment: |-
+ Parameters:
+ 0: the terminator that is missing
+ MISSING_TYPEDEF_PARAMETERS:
+ template: Typedefs must have an explicit list of parameters.
+ tip: Try adding a parameter list.
+ MISSING_VARIABLE_IN_FOR_EACH:
+ template: "A loop variable must be declared in a for-each loop before the 'in', but none was found."
+ tip: Try declaring a loop variable.
+ MIXED_PARAMETER_GROUPS:
+ template: "Can't have both positional and named parameters in a single parameter list."
+ tip: Try choosing a single style of optional parameters.
+ MIXIN_DECLARES_CONSTRUCTOR:
+ copyFromCfe: true
+ MODIFIER_OUT_OF_ORDER:
+ copyFromCfe: true
+ MULTIPLE_EXTENDS_CLAUSES:
+ copyFromCfe: true
+ MULTIPLE_IMPLEMENTS_CLAUSES:
+ template: Each class or mixin definition can have at most one implements clause.
+ tip: Try combining all of the implements clauses into a single clause.
+ MULTIPLE_LIBRARY_DIRECTIVES:
+ copyFromCfe: true
+ MULTIPLE_NAMED_PARAMETER_GROUPS:
+ template: "Can't have multiple groups of named parameters in a single parameter list."
+ tip: Try combining all of the groups into a single group.
+ MULTIPLE_ON_CLAUSES:
+ copyFromCfe: true
+ MULTIPLE_PART_OF_DIRECTIVES:
+ copyFromCfe: true
+ MULTIPLE_POSITIONAL_PARAMETER_GROUPS:
+ template: "Can't have multiple groups of positional parameters in a single parameter list."
+ tip: Try combining all of the groups into a single group.
+ MULTIPLE_VARIABLES_IN_FOR_EACH:
+ template: "A single loop variable must be declared in a for-each loop before the 'in', but {0} were found."
+ tip: Try moving all but one of the declarations inside the loop body.
+ comment: |-
+ Parameters:
+ 0: the number of variables being declared
+ MULTIPLE_VARIANCE_MODIFIERS:
+ copyFromCfe: true
+ MULTIPLE_WITH_CLAUSES:
+ copyFromCfe: true
+ NAMED_FUNCTION_EXPRESSION:
+ template: "Function expressions can't be named."
+ tip: Try removing the name, or moving the function expression to a function declaration statement.
+ NAMED_FUNCTION_TYPE:
+ template: "Function types can't be named."
+ tip: "Try replacing the name with the keyword 'Function'."
+ NAMED_PARAMETER_OUTSIDE_GROUP:
+ template: "Named parameters must be enclosed in curly braces ('{' and '}')."
+ tip: Try surrounding the named parameters in curly braces.
+ NATIVE_CLAUSE_IN_NON_SDK_CODE:
+ template: Native clause can only be used in the SDK and code that is loaded through native extensions.
+ tip: Try removing the native clause.
+ NATIVE_CLAUSE_SHOULD_BE_ANNOTATION:
+ copyFromCfe: true
+ NATIVE_FUNCTION_BODY_IN_NON_SDK_CODE:
+ template: Native functions can only be declared in the SDK and code that is loaded through native extensions.
+ tip: "Try removing the word 'native'."
+ NON_CONSTRUCTOR_FACTORY:
+ template: Only a constructor can be declared to be a factory.
+ tip: "Try removing the keyword 'factory'."
+ NON_IDENTIFIER_LIBRARY_NAME:
+ template: The name of a library must be an identifier.
+ tip: Try using an identifier as the name of the library.
+ NON_PART_OF_DIRECTIVE_IN_PART:
+ template: The part-of directive must be the only directive in a part.
+ tip: Try removing the other directives, or moving them to the library for which this is a part.
+ NON_STRING_LITERAL_AS_URI:
+ template: The URI must be a string literal.
+ tip: Try enclosing the URI in either single or double quotes.
+ NON_USER_DEFINABLE_OPERATOR:
+ template: "The operator '{0}' isn't user definable."
+ comment: |-
+ Parameters:
+ 0: the operator that the user is trying to define
+ NORMAL_BEFORE_OPTIONAL_PARAMETERS:
+ template: Normal parameters must occur before optional parameters.
+ tip: Try moving all of the normal parameters before the optional parameters.
+ NULL_AWARE_CASCADE_OUT_OF_ORDER:
+ copyFromCfe: true
+ POSITIONAL_AFTER_NAMED_ARGUMENT:
+ template: Positional arguments must occur before named arguments.
+ tip: Try moving all of the positional arguments before the named arguments.
+ POSITIONAL_PARAMETER_OUTSIDE_GROUP:
+ template: "Positional parameters must be enclosed in square brackets ('[' and ']')."
+ tip: Try surrounding the positional parameters in square brackets.
+ PREFIX_AFTER_COMBINATOR:
+ copyFromCfe: true
+ REDIRECTING_CONSTRUCTOR_WITH_BODY:
+ copyFromCfe: true
+ REDIRECTION_IN_NON_FACTORY_CONSTRUCTOR:
+ copyFromCfe: true
+ SETTER_CONSTRUCTOR:
+ copyFromCfe: true
+ SETTER_IN_FUNCTION:
+ template: "Setters can't be defined within methods or functions."
+ tip: Try moving the setter outside the method or function.
+ STACK_OVERFLOW:
+ copyFromCfe: true
+ STATIC_CONSTRUCTOR:
+ copyFromCfe: true
+ STATIC_GETTER_WITHOUT_BODY:
+ template: "A 'static' getter must have a body."
+ tip: "Try adding a body to the getter, or removing the keyword 'static'."
+ STATIC_OPERATOR:
+ copyFromCfe: true
+ STATIC_SETTER_WITHOUT_BODY:
+ template: "A 'static' setter must have a body."
+ tip: "Try adding a body to the setter, or removing the keyword 'static'."
+ STATIC_TOP_LEVEL_DECLARATION:
+ template: "Top-level declarations can't be declared to be static."
+ tip: "Try removing the keyword 'static'."
+ SWITCH_HAS_CASE_AFTER_DEFAULT_CASE:
+ copyFromCfe: true
+ SWITCH_HAS_MULTIPLE_DEFAULT_CASES:
+ copyFromCfe: true
+ TOP_LEVEL_OPERATOR:
+ copyFromCfe: true
+ TYPEDEF_IN_CLASS:
+ copyFromCfe: true
+ TYPE_ARGUMENTS_ON_TYPE_VARIABLE:
+ copyFromCfe: true
+ TYPE_BEFORE_FACTORY:
+ copyFromCfe: true
+ TYPE_PARAMETER_ON_CONSTRUCTOR:
+ copyFromCfe: true
+ TYPE_PARAMETER_ON_OPERATOR:
+ template: "Types parameters aren't allowed when defining an operator."
+ tip: Try removing the type parameters.
+ comment: |-
+ 7.1.1 Operators: Type parameters are not syntactically supported on an
+ operator.
+ UNEXPECTED_TERMINATOR_FOR_PARAMETER_GROUP:
+ template: "There is no '{0}' to open a parameter group."
+ tip: "Try inserting the '{0}' at the appropriate location."
+ comment: |-
+ Parameters:
+ 0: the starting character that was missing
+ UNEXPECTED_TOKEN:
+ template: "Unexpected text '{0}'."
+ tip: Try removing the text.
+ comment: |-
+ Parameters:
+ 0: the unexpected text that was found
+ VAR_AND_TYPE:
+ copyFromCfe: true
+ VAR_AS_TYPE_NAME:
+ copyFromCfe: true
+ VAR_CLASS:
+ template: "Classes can't be declared to be 'var'."
+ tip: "Try removing the keyword 'var'."
+ VAR_ENUM:
+ template: "Enums can't be declared to be 'var'."
+ tip: "Try removing the keyword 'var'."
+ VAR_RETURN_TYPE:
+ copyFromCfe: true
+ VAR_TYPEDEF:
+ template: "Typedefs can't be declared to be 'var'."
+ tip: "Try removing the keyword 'var', or replacing it with the name of the return type."
+ VOID_WITH_TYPE_ARGUMENTS:
+ copyFromCfe: true
+ WITH_BEFORE_EXTENDS:
+ copyFromCfe: true
+ WRONG_SEPARATOR_FOR_POSITIONAL_PARAMETER:
+ template: "The default value of a positional parameter should be preceded by '='."
+ tip: "Try replacing the ':' with '='."
+ WRONG_TERMINATOR_FOR_PARAMETER_GROUP:
+ template: "Expected '{0}' to close parameter group."
+ tip: "Try replacing '{0}' with '{1}'."
+ comment: |-
+ Parameters:
+ 0: the terminator that was expected
+ 1: the terminator that was found
+PubspecWarningCode:
+ ASSET_DIRECTORY_DOES_NOT_EXIST:
+ template: "The asset directory '{0}' doesn't exist."
+ tip: Try creating the directory or fixing the path to the directory.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the path to the asset directory as given in the file.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an asset list contains a value
+ referencing a directory that doesn't exist.
+
+ #### Example
+
+ Assuming that the directory `assets` doesn't exist, the following code
+ produces this diagnostic because it's listed as a directory containing
+ assets:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter:
+ assets:
+ - assets/
+ ```
+
+ #### Common fixes
+
+ If the path is correct, then create a directory at that path.
+
+ If the path isn't correct, then change the path to match the path of the
+ directory containing the assets.
+ ASSET_DOES_NOT_EXIST:
+ template: "The asset file '{0}' doesn't exist."
+ tip: Try creating the file or fixing the path to the file.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the path to the asset as given in the file.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an asset list contains a value
+ referencing a file that doesn't exist.
+
+ #### Example
+
+ Assuming that the file `doesNotExist.gif` doesn't exist, the following code
+ produces this diagnostic because it's listed as an asset:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter:
+ assets:
+ - doesNotExist.gif
+ ```
+
+ #### Common fixes
+
+ If the path is correct, then create a file at that path.
+
+ If the path isn't correct, then change the path to match the path of the
+ file containing the asset.
+ ASSET_FIELD_NOT_LIST:
+ template: "The value of the 'asset' field is expected to be a list of relative file paths."
+ tip: Try converting the value to be a list of relative file paths.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the value of the `asset` key
+ isn't a list.
+
+ #### Example
+
+ The following code produces this diagnostic because the value of the assets
+ key is a string when a list is expected:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter:
+ assets: assets/
+ ```
+
+ #### Common fixes
+
+ Change the value of the asset list so that it's a list:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter:
+ assets:
+ - assets/
+ ```
+ ASSET_NOT_STRING:
+ template: Assets are required to be file paths (strings).
+ tip: Try converting the value to be a string.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when an asset list contains a value
+ that isn't a string.
+
+ #### Example
+
+ The following code produces this diagnostic because the asset list contains
+ a map:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter:
+ assets:
+ - image.gif: true
+ ```
+
+ #### Common fixes
+
+ Change the asset list so that it only contains valid POSIX-style file
+ paths:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter:
+ assets:
+ - image.gif
+ ```
+ DEPENDENCIES_FIELD_NOT_MAP:
+ template: "The value of the '{0}' field is expected to be a map."
+ tip: Try converting the value to be a map.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the value of either the
+ `dependencies` or `dev_dependencies` key isn't a map.
+
+ #### Example
+
+ The following code produces this diagnostic because the value of the
+ top-level `dependencies` key is a list:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ dependencies:
+ - meta
+ ```
+
+ #### Common fixes
+
+ Use a map as the value of the `dependencies` key:
+
+ ```yaml
+ %uri='pubspec.yaml'
+ name: example
+ dependencies:
+ meta: ^1.0.2
+ ```
+ DEPRECATED_FIELD:
+ template: "The '{0}' field is no longer used and can be removed."
+ tip: Try removing the field.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a key is used in a
+ `pubspec.yaml` file that was deprecated. Unused keys take up space and
+ might imply semantics that are no longer valid.
+
+ #### Example
+
+ The following code produces this diagnostic because the `author` key is no
+ longer being used:
+
+ ```dart
+ %uri="pubspec.yaml"
+ name: example
+ author: 'Dash'
+ ```
+
+ #### Common fixes
+
+ Remove the deprecated key:
+
+ ```dart
+ %uri="pubspec.yaml"
+ name: example
+ ```
+ FLUTTER_FIELD_NOT_MAP:
+ template: "The value of the 'flutter' field is expected to be a map."
+ tip: Try converting the value to be a map.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the value of the `flutter` key
+ isn't a map.
+
+ #### Example
+
+ The following code produces this diagnostic because the value of the
+ top-level `flutter` key is a string:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter: true
+ ```
+
+ #### Common fixes
+
+ If you need to specify Flutter-specific options, then change the value to
+ be a map:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ flutter:
+ uses-material-design: true
+ ```
+
+ If you don't need to specify Flutter-specific options, then remove the
+ `flutter` key:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ ```
+ INVALID_DEPENDENCY:
+ template: "Publishable packages can't have '{0}' dependencies."
+ tip: "Try adding a 'publish_to: none' entry to mark the package as not for publishing or remove the {0} dependency."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the kind of dependency.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a package under either
+ `dependencies` or `dev_dependencies` is not a pub, `git`, or `path` based
+ dependency.
+
+ See [Package dependencies](https://dart.dev/tools/pub/dependencies) for
+ more information about the kind of dependencies that are supported.
+
+ #### Example
+
+ The following code produces this diagnostic because the dependency on the
+ package `transmogrify` is not a pub, `git`, or `path` based dependency:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ dependencies:
+ transmogrify:
+ hosted:
+ name: transmogrify
+ url: http://your-package-server.com
+ version: ^1.4.0
+ ```
+
+ #### Common fixes
+
+ If you want to publish your package to `pub.dev`, then change the
+ dependencies to ones that are supported by `pub`.
+
+ If you don't want to publish your package to `pub.dev`, then add a
+ `publish_to: none` entry to mark the package as one that isn't intended to
+ be published:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ publish_to: none
+ dependencies:
+ transmogrify:
+ hosted:
+ name: transmogrify
+ url: http://your-package-server.com
+ version: ^1.4.0
+ ```
+ MISSING_NAME:
+ template: "The 'name' field is required but missing."
+ tip: "Try adding a field named 'name'."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when there's no top-level `name` key.
+ The `name` key provides the name of the package, which is required.
+
+ #### Example
+
+ The following code produces this diagnostic because the package doesn't
+ have a name:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ dependencies:
+ meta: ^1.0.2
+ ```
+
+ #### Common fixes
+
+ Add the top-level key `name` with a value that's the name of the package:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ dependencies:
+ meta: ^1.0.2
+ ```
+ NAME_NOT_STRING:
+ template: "The value of the 'name' field is required to be a string."
+ tip: Try converting the value to be a string.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the top-level `name` key has a
+ value that isn't a string.
+
+ #### Example
+
+ The following code produces this diagnostic because the value following the
+ `name` key is a list:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name:
+ - example
+ ```
+
+ #### Common fixes
+
+ Replace the value with a string:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ ```
+ PATH_DOES_NOT_EXIST:
+ template: "The path '{0}' doesn't exist."
+ tip: Try creating the referenced path or using a path that exists.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the path to the dependency as given in the file.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a dependency has a `path` key
+ referencing a directory that doesn't exist.
+
+ #### Example
+
+ Assuming that the directory `doesNotExist` doesn't exist, the following
+ code produces this diagnostic because it's listed as the path of a package:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ dependencies:
+ local_package:
+ path: doesNotExist
+ ```
+
+ #### Common fixes
+
+ If the path is correct, then create a directory at that path.
+
+ If the path isn't correct, then change the path to match the path to the
+ root of the package.
+ PATH_NOT_POSIX:
+ template: "The path '{0}' isn't a POSIX-style path."
+ tip: Try converting the value to a POSIX-style path.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the path as given in the file.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a dependency has a `path` key
+ whose value is a string, but isn't a POSIX-style path.
+
+ #### Example
+
+ The following code produces this diagnostic because the path following the
+ `path` key is a Windows path:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ dependencies:
+ local_package:
+ path: E:\local_package
+ ```
+
+ #### Common fixes
+
+ Convert the path to a POSIX path.
+ PATH_PUBSPEC_DOES_NOT_EXIST:
+ template: "The directory '{0}' doesn't contain a pubspec."
+ tip: Try creating a pubspec in the referenced directory or using a path that has a pubspec.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the path to the dependency as given in the file.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a dependency has a `path` key
+ that references a directory that doesn't contain a `pubspec.yaml` file.
+
+ #### Example
+
+ Assuming that the directory `local_package` doesn't contain a file named
+ `pubspec.yaml`, the following code produces this diagnostic because it's
+ listed as the path of a package:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: example
+ dependencies:
+ local_package:
+ path: local_package
+ ```
+
+ #### Common fixes
+
+ If the path is intended to be the root of a package, then add a
+ `pubspec.yaml` file in the directory:
+
+ ```yaml
+ %uri="pubspec.yaml"
+ name: local_package
+ ```
+
+ If the path is wrong, then replace it with a the correct path.
+ UNNECESSARY_DEV_DEPENDENCY:
+ template: "The dev dependency on {0} is unnecessary because there is also a normal dependency on that package."
+ tip: Try removing the dev dependency.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the package in the dev_dependency list.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when there's an entry under
+ `dev_dependencies` for a package that is also listed under `dependencies`.
+ The packages under `dependencies` are available to all of the code in the
+ package, so there's no need to also list them under `dev_dependencies`.
+
+ #### Example
+
+ The following code produces this diagnostic because the package `meta` is
+ listed under both `dependencies` and `dev_dependencies`:
+
+ ```yaml
+ %uri='pubspec.yaml'
+ name: example
+ dependencies:
+ meta: ^1.0.2
+ dev_dependencies:
+ meta: ^1.0.2
+ ```
+
+ #### Common fixes
+
+ Remove the entry under `dev_dependencies` (and the `dev_dependencies` key
+ if that's the only package listed there):
+
+ ```yaml
+ %uri='pubspec.yaml'
+ name: example
+ dependencies:
+ meta: ^1.0.2
+ ```
+StaticWarningCode:
+ DEAD_NULL_AWARE_EXPRESSION:
+ template: "The left operand can't be null, so the right operand is never executed."
+ tip: Try removing the operator and the right operand.
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic in two cases.
+
+ The first is when the left operand of an `??` operator can't be `null`.
+ The right operand is only evaluated if the left operand has the value
+ `null`, and because the left operand can't be `null`, the right operand is
+ never evaluated.
+
+ The second is when the left-hand side of an assignment using the `??=`
+ operator can't be `null`. The right-hand side is only evaluated if the
+ left-hand side has the value `null`, and because the left-hand side can't
+ be `null`, the right-hand side is never evaluated.
+
+ #### Example
+
+ The following code produces this diagnostic because `x` can't be `null`:
+
+ ```dart
+ int f(int x) {
+ return x ?? [!0!];
+ }
+ ```
+
+ The following code produces this diagnostic because `f` can't be `null`:
+
+ ```dart
+ class C {
+ int f = -1;
+
+ void m(int x) {
+ f ??= [!x!];
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If the diagnostic is reported for an `??` operator, then remove the `??`
+ operator and the right operand:
+
+ ```dart
+ int f(int x) {
+ return x;
+ }
+ ```
+
+ If the diagnostic is reported for an assignment, and the assignment isn't
+ needed, then remove the assignment:
+
+ ```dart
+ class C {
+ int f = -1;
+
+ void m(int x) {
+ }
+ }
+ ```
+
+ If the assignment is needed, but should be based on a different condition,
+ then rewrite the code to use `=` and the different condition:
+
+ ```dart
+ class C {
+ int f = -1;
+
+ void m(int x) {
+ if (f < 0) {
+ f = x;
+ }
+ }
+ }
+ ```
+ INVALID_NULL_AWARE_OPERATOR:
+ template: "The receiver can't be null, so the null-aware operator '{0}' is unnecessary."
+ tip: "Try replacing the operator '{0}' with '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the null-aware operator that is invalid
+ 1: the non-null-aware operator that can replace the invalid operator
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a null-aware operator (`?.`,
+ `?..`, `?[`, `?..[`, or `...?`) is used on a receiver that's known to be
+ non-nullable.
+
+ #### Example
+
+ The following code produces this diagnostic because `s` can't be `null`:
+
+ ```dart
+ int? getLength(String s) {
+ return s[!?.!]length;
+ }
+ ```
+
+ The following code produces this diagnostic because `a` can't be `null`:
+
+ ```dart
+ var a = [];
+ var b = [[!...?!]a];
+ ```
+
+ The following code produces this diagnostic because `s?.length` can't
+ return `null`:
+
+ ```dart
+ void f(String? s) {
+ s?.length[!?.!]isEven;
+ }
+ ```
+
+ The reason `s?.length` can't return `null` is because the null-aware
+ operator following `s` short-circuits the evaluation of both `length` and
+ `isEven` if `s` is `null`. In other words, if `s` is `null`, then neither
+ `length` nor `isEven` will be invoked, and if `s` is non-`null`, then
+ `length` can't return a `null` value. Either way, `isEven` can't be invoked
+ on a `null` value, so the null-aware operator is not necessary. See
+ [Understanding null safety](/null-safety/understanding-null-safety#smarter-null-aware-methods)
+ for more details.
+
+ The following code produces this diagnostic because `s` can't be `null`.
+
+ ```dart
+ void f(Object? o) {
+ var s = o as String;
+ s[!?.!]length;
+ }
+ ```
+
+ The reason `s` can't be null, despite the fact that `o` can be `null`, is
+ because of the cast to `String`, which is a non-nullable type. If `o` ever
+ has the value `null`, the cast will fail and the invocation of `length`
+ will not happen.
+
+ #### Common fixes
+
+ Replace the null-aware operator with a non-null-aware equivalent; for
+ example, change `?.` to `.`:
+
+ ```dart
+ int getLength(String s) {
+ return s.length;
+ }
+ ```
+
+ (Note that the return type was also changed to be non-nullable, which might
+ not be appropriate in some cases.)
+ INVALID_NULL_AWARE_OPERATOR_AFTER_SHORT_CIRCUIT:
+ sharedName: INVALID_NULL_AWARE_OPERATOR
+ template: "The receiver can't be null because of short-circuiting, so the null-aware operator '{0}' can't be used."
+ tip: "Try replacing the operator '{0}' with '{1}'."
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the null-aware operator that is invalid
+ 1: the non-null-aware operator that can replace the invalid operator
+ INVALID_OVERRIDE_DIFFERENT_DEFAULT_VALUES_NAMED:
+ template: "Parameters can't override default values, this method overrides '{0}.{1}' where '{2}' has a different value."
+ tip: Try using the same default value in both methods.
+ comment: |-
+ 7.1 Instance Methods: It is a static warning if an instance method
+ <i>m1</i> overrides an instance member <i>m2</i>, the signature of
+ <i>m2</i> explicitly specifies a default value for a formal parameter
+ <i>p</i> and the signature of <i>m1</i> specifies a different default value
+ for <i>p</i>.
+ INVALID_OVERRIDE_DIFFERENT_DEFAULT_VALUES_POSITIONAL:
+ template: "Parameters can't override default values, this method overrides '{0}.{1}' where this positional parameter has a different value."
+ tip: Try using the same default value in both methods.
+ comment: |-
+ 7.1 Instance Methods: It is a static warning if an instance method
+ <i>m1</i> overrides an instance member <i>m2</i>, the signature of
+ <i>m2</i> explicitly specifies a default value for a formal parameter
+ <i>p</i> and the signature of <i>m1</i> specifies a different default value
+ for <i>p</i>.
+ MISSING_ENUM_CONSTANT_IN_SWITCH:
+ template: "Missing case clause for '{0}'."
+ tip: Try adding a case clause for the missing constant, or adding a default clause.
+ hasPublishedDocs: true
+ comment: |-
+ Parameters:
+ 0: the name of the constant that is missing
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when a `switch` statement for an enum
+ doesn't include an option for one of the values in the enumeration.
+
+ Note that `null` is always a possible value for an enum and therefore also
+ must be handled.
+
+ #### Examples
+
+ The following code produces this diagnostic because the enum constant `e2`
+ isn't handled:
+
+ ```dart
+ enum E { e1, e2 }
+
+ void f(E e) {
+ [!switch (e)!] {
+ case E.e1:
+ break;
+ }
+ }
+ ```
+
+ #### Common fixes
+
+ If there's special handling for the missing values, then add a `case`
+ clause for each of the missing values:
+
+ ```dart
+ enum E { e1, e2 }
+
+ void f(E e) {
+ switch (e) {
+ case E.e1:
+ break;
+ case E.e2:
+ break;
+ }
+ }
+ ```
+
+ If the missing values should be handled the same way, then add a `default`
+ clause:
+
+ ```dart
+ enum E { e1, e2 }
+
+ void f(E e) {
+ switch (e) {
+ case E.e1:
+ break;
+ default:
+ break;
+ }
+ }
+ ```
+ TODO(brianwilkerson) This documentation will need to be updated when NNBD
+ ships.
+ UNNECESSARY_NON_NULL_ASSERTION:
+ template: "The '!' will have no effect because the receiver can't be null."
+ tip: "Try removing the '!' operator."
+ hasPublishedDocs: true
+ comment: No parameters.
+ documentation: |-
+ #### Description
+
+ The analyzer produces this diagnostic when the operand of the `!` operator
+ can't be `null`.
+
+ #### Example
+
+ The following code produces this diagnostic because `x` can't be `null`:
+
+ ```dart
+ int f(int x) {
+ return x[!!!];
+ }
+ ```
+
+ #### Common fixes
+
+ Remove the null check operator (`!`):
+
+ ```dart
+ int f(int x) {
+ return x;
+ }
+ ```
+
diff --git a/pkg/analyzer/test/generated/constant_test.dart b/pkg/analyzer/test/generated/constant_test.dart
index eaad3c1..8bbf1fa 100644
--- a/pkg/analyzer/test/generated/constant_test.dart
+++ b/pkg/analyzer/test/generated/constant_test.dart
@@ -27,8 +27,7 @@
return;
}
expect(
- typeArguments.map(
- (arg) => arg.toTypeValue()!.getDisplayString(withNullability: true)),
+ typeArguments.map((arg) => arg.getDisplayString(withNullability: true)),
equals(typeArgumentNames),
);
}
diff --git a/pkg/analyzer/test/src/dart/constant/evaluation_test.dart b/pkg/analyzer/test/src/dart/constant/evaluation_test.dart
index 9facdf6..9044238 100644
--- a/pkg/analyzer/test/src/dart/constant/evaluation_test.dart
+++ b/pkg/analyzer/test/src/dart/constant/evaluation_test.dart
@@ -166,6 +166,32 @@
);
}
+ test_identical_functionReference_implicitTypeArgs_differentTypes() async {
+ await resolveTestCode('''
+void foo<T>(T a) {}
+const void Function(int) f = foo;
+const void Function(String) g = foo;
+const c = identical(f, g);
+''');
+ expect(
+ _evaluateConstant('c'),
+ _boolValue(false),
+ );
+ }
+
+ test_identical_functionReference_implicitTypeArgs_sameTypes() async {
+ await resolveTestCode('''
+void foo<T>(T a) {}
+const void Function(int) f = foo;
+const void Function(int) g = foo;
+const c = identical(f, g);
+''');
+ expect(
+ _evaluateConstant('c'),
+ _boolValue(true),
+ );
+ }
+
test_identical_functionReference_uninstantiated_sameElement() async {
await resolveTestCode('''
void foo<T>(T a) {}
@@ -394,6 +420,21 @@
expect(result.toIntValue(), 0xFF);
}
+ test_visitConditionalExpression_instantiatedFunctionType_variable() async {
+ await resolveTestCode('''
+void f<T>(T p, {T? q}) {}
+
+const void Function<T>(T p) g = f;
+
+const bool b = false;
+const void Function(int p) h = b ? g : g;
+''');
+ var result = _evaluateConstant('h');
+ assertType(result.type, 'void Function(int, {int? q})');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, ['int']);
+ }
+
test_visitFunctionReference_explicitTypeArgs_complexExpression() async {
await resolveTestCode('''
const b = true;
@@ -516,6 +557,18 @@
_assertTypeArguments(result, null);
}
+ test_visitPrefixedIdentifier_genericFunction_instantiated() async {
+ await resolveTestCode('''
+import '' as self;
+void f<T>(T a) {}
+const void Function(int) g = self.f;
+''');
+ var result = _evaluateConstant('g');
+ assertType(result.type, 'void Function(int)');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, null);
+ }
+
test_visitSimpleIdentifier_className() async {
await resolveTestCode('''
const a = C;
@@ -525,6 +578,76 @@
expect(result.type, typeProvider.typeType);
assertType(result.toTypeValue(), 'C*');
}
+
+ test_visitSimpleIdentifier_genericFunction_instantiated() async {
+ await resolveTestCode('''
+void f<T>(T a) {}
+const void Function(int) g = f;
+''');
+ var result = _evaluateConstant('g');
+ assertType(result.type, 'void Function(int)');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, null);
+ }
+
+ test_visitSimpleIdentifier_genericVariable_instantiated() async {
+ await resolveTestCode('''
+void f<T>(T a) {}
+const g = f;
+const void Function(int) h = g;
+''');
+ var result = _evaluateConstant('h');
+ assertType(result.type, 'void Function(int)');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, ['int']);
+ }
+
+ test_visitSimpleIdentifier_instantiatedFunctionType_field() async {
+ await resolveTestCode('''
+void f<T>(T a, {T? b}) {}
+
+class C {
+ static const void Function<T>(T a) g = f;
+ static const void Function(int a) h = g;
+}
+''');
+ var result = _evaluateConstantLocal('h')!;
+ assertType(result.type, 'void Function(int, {int? b})');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, ['int']);
+ }
+
+ test_visitSimpleIdentifier_instantiatedFunctionType_parameter() async {
+ await resolveTestCode('''
+void f<T>(T a, {T? b}) {}
+
+class C {
+ const C(void Function<T>(T a) g) : h = g;
+ final void Function(int a) h;
+}
+
+const c = C(f);
+''');
+ var result = _evaluateConstant('c');
+ var field = result.fields!['h']!;
+ assertType(field.type, 'void Function(int, {int? b})');
+ assertElement(field.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(field, ['int']);
+ }
+
+ test_visitSimpleIdentifier_instantiatedFunctionType_variable() async {
+ await resolveTestCode('''
+void f<T>(T a, {T? b}) {}
+
+const void Function<T>(T a) g = f;
+
+const void Function(int a) h = g;
+''');
+ var result = _evaluateConstant('h');
+ assertType(result.type, 'void Function(int, {int? b})');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, ['int']);
+ }
}
@reflectiveTest
@@ -1515,6 +1638,31 @@
expect(result.toBoolValue(), true);
}
+ test_visitPrefixedIdentifier_function() async {
+ await resolveTestCode('''
+import '' as self;
+void f(int a) {}
+const g = self.f;
+''');
+ var result = _evaluateConstant('g');
+ assertType(result.type, 'void Function(int)');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, null);
+ }
+
+ test_visitPrefixedIdentifier_genericVariable_uninstantiated() async {
+ await resolveTestCode('''
+import '' as self;
+void f<T>(T a) {}
+const g = f;
+const h = self.g;
+''');
+ var result = _evaluateConstant('h');
+ assertType(result.type, 'void Function<T>(T)');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, null);
+ }
+
test_visitPropertyAccess_fromExtension() async {
await resolveTestCode('''
extension ExtObject on Object {
@@ -1543,6 +1691,29 @@
expect(result.toTypeValue(), typeProvider.dynamicType);
}
+ test_visitSimpleIdentifier_function() async {
+ await resolveTestCode('''
+void f(int a) {}
+const g = f;
+''');
+ var result = _evaluateConstant('g');
+ assertType(result.type, 'void Function(int)');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, null);
+ }
+
+ test_visitSimpleIdentifier_genericVariable_uninstantiated() async {
+ await resolveTestCode('''
+void f<T>(T a) {}
+const g = f;
+const h = g;
+''');
+ var result = _evaluateConstant('h');
+ assertType(result.type, 'void Function<T>(T)');
+ assertElement(result.toFunctionValue(), findElement.topFunction('f'));
+ _assertTypeArguments(result, null);
+ }
+
test_visitSimpleIdentifier_inEnvironment() async {
await resolveTestCode(r'''
const a = b;
@@ -1620,8 +1791,7 @@
return;
}
expect(
- typeArguments.map(
- (arg) => arg.toTypeValue()!.getDisplayString(withNullability: true)),
+ typeArguments.map((arg) => arg.getDisplayString(withNullability: true)),
equals(typeArgumentNames),
);
}
diff --git a/pkg/analyzer/tool/messages/error_code_info.dart b/pkg/analyzer/tool/messages/error_code_info.dart
index 56a4947..4a94bf8 100644
--- a/pkg/analyzer/tool/messages/error_code_info.dart
+++ b/pkg/analyzer/tool/messages/error_code_info.dart
@@ -93,8 +93,9 @@
}
}
-/// In-memory representation of error code information obtained from a
-/// `messages.yaml` file.
+/// In-memory representation of error code information obtained from either a
+/// `messages.yaml` file. Supports both the analyzer and front_end message file
+/// formats.
class ErrorCodeInfo {
/// Pattern used by the front end to identify placeholders in error message
/// strings. TODO(paulberry): share this regexp (and the code for interpreting
@@ -106,6 +107,20 @@
/// error codes that corresponds to this error code, if any.
final List<String> analyzerCode;
+ /// If present, a documentation comment that should be associated with the
+ /// error in code generated output.
+ final String? comment;
+
+ /// `true` if this error should be copied from an error in the CFE. The
+ /// purpose of this field is so that the documentation for the error can exist
+ /// in the analyzer's messages.yaml file but the error text can come from the
+ /// CFE's messages.yaml file. TODO(paulberry): add support for documentation
+ /// to the CFE's messages.yaml file so that this isn't necessary.
+ final bool copyFromCfe;
+
+ /// If present, user-facing documentation for the error.
+ final String? documentation;
+
/// `true` if diagnostics with this code have documentation for them that has
/// been published.
final bool hasPublishedDocs;
@@ -114,8 +129,16 @@
/// in the analyzer's `fastaAnalyzerErrorCodes` table.
final int? index;
- /// The template for the error message.
- final String template;
+ /// Indicates whether this error is caused by an unresolved identifier.
+ final bool isUnresolvedIdentifier;
+
+ /// If present, indicates that this error code has a special name for
+ /// presentation to the user, that is potentially shared with other error
+ /// codes.
+ final String? sharedName;
+
+ /// The template for the error message, or `null` if [copyFromCfe] is `true`.
+ final String? template;
/// If the error code has an associated tip/correction message, the template
/// for it.
@@ -123,18 +146,40 @@
ErrorCodeInfo(
{this.analyzerCode = const [],
+ this.comment,
+ this.copyFromCfe = false,
+ this.documentation,
this.hasPublishedDocs = false,
this.index,
- required this.template,
- this.tip});
+ this.isUnresolvedIdentifier = false,
+ this.sharedName,
+ this.template,
+ this.tip}) {
+ if (copyFromCfe) {
+ if (template != null) {
+ throw "Error codes marked `copyFromCfe: true` can't have a template.";
+ }
+ } else {
+ if (template == null) {
+ throw 'Error codes must have a template unless they are marked '
+ '`copyFromCfe: true`.';
+ }
+ }
+ }
/// Decodes an [ErrorCodeInfo] object from its YAML representation.
ErrorCodeInfo.fromYaml(Map<Object?, Object?> yaml)
: this(
analyzerCode: _decodeAnalyzerCode(yaml['analyzerCode']),
+ comment: yaml['comment'] as String?,
+ copyFromCfe: yaml['copyFromCfe'] as bool? ?? false,
+ documentation: yaml['documentation'] as String?,
hasPublishedDocs: yaml['hasPublishedDocs'] as bool? ?? false,
index: yaml['index'] as int?,
- template: yaml['template'] as String,
+ isUnresolvedIdentifier:
+ yaml['isUnresolvedIdentifier'] as bool? ?? false,
+ sharedName: yaml['sharedName'] as String?,
+ template: yaml['template'] as String?,
tip: yaml['tip'] as String?);
/// Generates a dart declaration for this error code, suitable for inclusion
@@ -145,7 +190,8 @@
out.writeln('$className(');
out.writeln("'$errorCode',");
final placeholderToIndexMap = _computePlaceholderToIndexMap();
- out.writeln(json.encode(_convertTemplate(placeholderToIndexMap, template)));
+ out.writeln(
+ json.encode(_convertTemplate(placeholderToIndexMap, template!)));
final tip = this.tip;
if (tip is String) {
out.write(',correction: ');
@@ -158,6 +204,20 @@
return out.toString();
}
+ /// Encodes this object into a YAML representation.
+ Map<Object?, Object?> toYaml() => {
+ if (copyFromCfe) 'copyFromCfe': true,
+ if (sharedName != null) 'sharedName': sharedName,
+ if (analyzerCode.isNotEmpty)
+ 'analyzerCode': _encodeAnalyzerCode(analyzerCode),
+ if (template != null) 'template': template,
+ if (tip != null) 'tip': tip,
+ if (isUnresolvedIdentifier) 'isUnresolvedIdentifier': true,
+ if (hasPublishedDocs) 'hasPublishedDocs': true,
+ if (comment != null) 'comment': comment,
+ if (documentation != null) 'documentation': documentation,
+ };
+
/// Given a messages.yaml entry, come up with a mapping from placeholder
/// patterns in its message and tip strings to their corresponding indices.
Map<String, int> _computePlaceholderToIndexMap() {
@@ -197,4 +257,12 @@
throw 'Unrecognized analyzer code: $value';
}
}
+
+ static Object _encodeAnalyzerCode(List<String> analyzerCode) {
+ if (analyzerCode.length == 1) {
+ return analyzerCode.single;
+ } else {
+ return analyzerCode;
+ }
+ }
}
diff --git a/pkg/analyzer/tool/messages/extract_errors_to_yaml.dart b/pkg/analyzer/tool/messages/extract_errors_to_yaml.dart
new file mode 100644
index 0000000..f0c3790
--- /dev/null
+++ b/pkg/analyzer/tool/messages/extract_errors_to_yaml.dart
@@ -0,0 +1,275 @@
+// Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// This script extracts data from the analyzer classes derived from `ErrorCode`
+// (as well as the comments next to their declarations) and produces a
+// `messages.yaml` file capturing the same information. In the future, we will
+// generate the `ErrorCode` derived classes from this `messages.yaml` file.
+//
+// TODO(paulberry): once code generation is in place, remove this script.
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:analyzer/dart/analysis/features.dart';
+import 'package:analyzer/dart/analysis/utilities.dart';
+import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/error/error.dart';
+import 'package:analyzer/src/dart/ast/token.dart';
+import 'package:analyzer/src/dart/error/todo_codes.dart';
+import 'package:analyzer/src/generated/parser.dart';
+import 'package:analyzer_utilities/package_root.dart' as pkg_root;
+import 'package:path/path.dart';
+import 'package:yaml/yaml.dart';
+
+import 'error_code_info.dart';
+
+main() {
+ var errorDeclarations = _findErrorDeclarations();
+ var generatedAnalyzerCodes = _computeGeneratedAnalyzerCodes();
+ var errorCodesByClass = _findErrorCodesByClass();
+ _generateYaml(errorCodesByClass, errorDeclarations, generatedAnalyzerCodes);
+}
+
+/// The path to the `analyzer` package.
+final String _analyzerPkgPath =
+ normalize(join(pkg_root.packageRoot, 'analyzer'));
+
+/// The path to the `analyzer` package.
+final String _frontEndPkgPath =
+ normalize(join(pkg_root.packageRoot, 'front_end'));
+
+/// Computes the set of `ParserErrorCode`s that are generated based on
+/// `pkg/front_end/messages.yaml`.
+Set<String> _computeGeneratedAnalyzerCodes() {
+ Map<dynamic, dynamic> messagesYaml = loadYaml(
+ File(join(_frontEndPkgPath, 'messages.yaml')).readAsStringSync());
+ var messages = decodeCfeMessagesYaml(messagesYaml);
+ var tables = CfeToAnalyzerErrorCodeTables(messages);
+ return tables.infoToAnalyzerCode.values.toSet();
+}
+
+/// Encodes [yaml] into a string parseable as YAML.
+///
+/// YAML is complex and we are just trying to do a good enough job for a one
+/// shot generation of a `messages.yaml` file, so instead of trying to
+/// exhaustively implement the YAML standard, we have a heuristic
+/// implementation, and then we double check that we can parse the result and
+/// get back the original data structures.
+String _encodeYaml(Map<Object?, Object?> yaml) {
+ var out = StringBuffer();
+ void visit(Map<Object?, Object?> yaml, String prefix) {
+ for (var entry in yaml.entries) {
+ var keyPart = '$prefix${entry.key}:';
+ var value = entry.value;
+ if (value is Map<Object?, Object?>) {
+ out.writeln(keyPart);
+ visit(value, '$prefix ');
+ } else if (value is String) {
+ if (value.contains('\n')) {
+ if (value.trim() != value) {
+ throw 'TODO(paulberry): handle a string with leading or trailing '
+ 'whitespace';
+ }
+ out.writeln('$keyPart |-');
+ var indented = value.replaceAll(RegExp('\n(?!\n)'), '\n$prefix ');
+ out.writeln('$prefix $indented');
+ } else if (value.contains('{') ||
+ value.contains(':') ||
+ value.contains("'") ||
+ value.trim() != value) {
+ out.writeln('$keyPart ${json.encode(value)}');
+ } else {
+ out.writeln('$keyPart $value');
+ }
+ } else if (value is bool) {
+ out.writeln('$keyPart $value');
+ } else {
+ throw 'TODO(paulberry): encode ${value.runtimeType}';
+ }
+ }
+ }
+
+ visit(yaml, '');
+ var result = out.toString();
+
+ // Double check that the result parses correctly.
+ try {
+ var parsedYaml = loadYaml(result);
+ if (json.encode(yaml) != json.encode(parsedYaml)) {
+ throw 'YAML did match after parsing';
+ }
+ } on Object {
+ print('=== Error in yaml file ===');
+ print(result);
+ print('===');
+ rethrow;
+ }
+ return result;
+}
+
+/// Extract comments from the parsed AST of a field declaration, so that we can
+/// include them in the YAML output.
+_CommentInfo _extractCommentInfo(FieldDeclaration fieldDeclaration) {
+ var firstToken = fieldDeclaration.metadata.beginToken ??
+ fieldDeclaration.firstTokenAfterCommentAndMetadata;
+ var commentToken = firstToken.precedingComments;
+ StringBuffer? documentationComment;
+ StringBuffer? otherComment;
+ while (commentToken != null) {
+ var lexeme = commentToken.lexeme;
+ if (lexeme.startsWith('///')) {
+ (documentationComment ??= StringBuffer())
+ .writeln(lexeme.replaceFirst(RegExp('/// ?'), '').trimRight());
+ } else if (lexeme.startsWith('/**')) {
+ (documentationComment ??= StringBuffer()).writeln(lexeme
+ .substring(0, lexeme.length - 2)
+ .replaceFirst(RegExp('/\\*\\*\n?'), '')
+ .replaceAll(RegExp(' *\\* ?'), '')
+ .trimRight());
+ } else if (lexeme.startsWith('//')) {
+ (otherComment ??= StringBuffer())
+ .writeln(lexeme.replaceFirst(RegExp('// ?'), '').trimRight());
+ } else if (lexeme.startsWith('/*')) {
+ (otherComment ??= StringBuffer()).writeln(lexeme
+ .substring(0, lexeme.length - 2)
+ .replaceFirst(RegExp('/\\*(\n| )?'), '')
+ .replaceAll(RegExp(' *(\\*|//) ?'), '')
+ .trimRight());
+ } else {
+ throw 'Unexpected comment type: ${json.encode(lexeme)}';
+ }
+ commentToken = commentToken.next as CommentToken?;
+ }
+ return _CommentInfo(
+ documentationComment: documentationComment?.toString().trim(),
+ otherComment: otherComment?.toString().trim());
+}
+
+/// Computes a map from class name to a list of all the error codes defined by
+/// that class. Uses the analyzer's global variable `errorCodeValues` to find
+/// all the error codes.
+Map<String, List<ErrorCode>> _findErrorCodesByClass() {
+ var errorCodesByClass = <String, List<ErrorCode>>{};
+ for (var errorCode in errorCodeValues) {
+ if (errorCode is ScannerErrorCode) {
+ continue; // Will deal with later
+ }
+ if (errorCode is TodoCode) {
+ continue; // It's not worth converting these to YAML.
+ }
+ var className = errorCode.runtimeType.toString();
+ (errorCodesByClass[className] ??= []).add(errorCode);
+ }
+ return errorCodesByClass;
+}
+
+/// Finds all the variable declaration ASTs in the analyzer that might represent
+/// error codes. The result is a two-tiered map, indexed first by class name
+/// and then by error code name.
+Map<String, Map<String, VariableDeclaration>> _findErrorDeclarations() {
+ var filePaths = [
+ join(_analyzerPkgPath, 'lib', 'src', 'analysis_options', 'error',
+ 'option_codes.dart'),
+ join(_analyzerPkgPath, 'lib', 'src', 'dart', 'error', 'ffi_code.dart'),
+ join(_analyzerPkgPath, 'lib', 'src', 'dart', 'error', 'hint_codes.dart'),
+ join(_analyzerPkgPath, 'lib', 'src', 'dart', 'error',
+ 'syntactic_errors.dart'),
+ join(_analyzerPkgPath, 'lib', 'src', 'error', 'codes.dart'),
+ join(_analyzerPkgPath, 'lib', 'src', 'manifest',
+ 'manifest_warning_code.dart'),
+ join(
+ _analyzerPkgPath, 'lib', 'src', 'pubspec', 'pubspec_warning_code.dart'),
+ ];
+ var result = <String, Map<String, VariableDeclaration>>{};
+ for (var filePath in filePaths) {
+ var unit = parseFile(
+ path: filePath, featureSet: FeatureSet.latestLanguageVersion())
+ .unit;
+ for (var declaration in unit.declarations) {
+ if (declaration is! ClassDeclaration) continue;
+ var className = declaration.name.name;
+ for (var member in declaration.members) {
+ if (member is! FieldDeclaration) continue;
+ for (var variable in member.fields.variables) {
+ (result[className] ??= {})[variable.name.name] = variable;
+ }
+ }
+ }
+ }
+ return result;
+}
+
+/// Combines the information in [errorCodesByClass] (obtained from
+/// [_findErrorCodesByClass]) and [errorDeclarations] (obtained from
+/// [_findErrorDeclarations]) into a YAML representation of the errors, and
+/// prints the resulting YAML.
+void _generateYaml(
+ Map<String, List<ErrorCode>> errorCodesByClass,
+ Map<String, Map<String, VariableDeclaration>> errorDeclarations,
+ Set<String> generatedAnalyzerCodes) {
+ var yaml = <String, Map<String, Object?>>{};
+ for (var entry in errorCodesByClass.entries) {
+ var yamlCodes = <String, Object?>{};
+ var className = entry.key;
+ yaml[className] = yamlCodes;
+ entry.value.sort((a, b) => a.name.compareTo(b.name));
+ for (var code in entry.value) {
+ var name = code.name;
+ var uniqueName = code.uniqueName;
+ if (!uniqueName.startsWith('$className.')) {
+ throw 'Unexpected unique name ${json.encode(uniqueName)}';
+ }
+ var uniqueNameSuffix = uniqueName.substring(className.length + 1);
+ if (uniqueNameSuffix.contains('.')) {
+ throw 'Unexpected unique name ${json.encode(uniqueName)}';
+ }
+ var classDeclaration = errorDeclarations[className];
+ if (classDeclaration == null) {
+ throw 'Could not find class declaration for $className';
+ }
+ var declaration = classDeclaration[uniqueNameSuffix];
+ if (declaration == null) {
+ throw 'Could not find declaration for $className.$uniqueNameSuffix';
+ }
+ var variableDeclarationList =
+ declaration.parent as VariableDeclarationList;
+ var fieldDeclaration = variableDeclarationList.parent as FieldDeclaration;
+ var commentInfo = _extractCommentInfo(fieldDeclaration);
+ var documentationComment = commentInfo.documentationComment;
+ var otherComment = commentInfo.otherComment;
+ ErrorCodeInfo errorCodeInfo;
+ if (className == 'ParserErrorCode' &&
+ generatedAnalyzerCodes.contains(name)) {
+ if (uniqueNameSuffix != name) {
+ throw "Auto-generated parser error codes can't be aliased";
+ }
+ errorCodeInfo = ErrorCodeInfo(
+ copyFromCfe: true,
+ comment: documentationComment,
+ documentation: otherComment);
+ } else {
+ errorCodeInfo = ErrorCodeInfo(
+ sharedName: uniqueNameSuffix == name ? null : name,
+ template: code.message,
+ tip: code.correction,
+ isUnresolvedIdentifier: code.isUnresolvedIdentifier,
+ hasPublishedDocs: code.hasPublishedDocs,
+ comment: documentationComment,
+ documentation: otherComment);
+ }
+ yamlCodes[uniqueNameSuffix] = errorCodeInfo.toYaml();
+ }
+ }
+ String encodedYaml = _encodeYaml(yaml);
+ print(encodedYaml);
+}
+
+class _CommentInfo {
+ final String? documentationComment;
+
+ final String? otherComment;
+
+ _CommentInfo({this.documentationComment, this.otherComment});
+}
diff --git a/pkg/analyzer/tool/messages/generate.dart b/pkg/analyzer/tool/messages/generate.dart
index 3aa0e3e..7c44d8d 100644
--- a/pkg/analyzer/tool/messages/generate.dart
+++ b/pkg/analyzer/tool/messages/generate.dart
@@ -171,7 +171,7 @@
}
String messageFromEntryTemplate(ErrorCodeInfo entry) {
- String template = entry.template;
+ String template = entry.template!;
String message = template.replaceAll(RegExp(r'#\w+'), '');
return message;
}
@@ -247,7 +247,7 @@
// TODO(paulberry): handle multiple analyzer codes
if (entry.index == null && entry.analyzerCode.length == 1) {
analyzerCode = entry.analyzerCode.single;
- template = entry.template;
+ template = entry.template!;
}
}
print(' ${fastaErrorCode.padRight(30)} --> $analyzerCode'
diff --git a/tools/VERSION b/tools/VERSION
index c71b57b..3eb35a7 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
MAJOR 2
MINOR 15
PATCH 0
-PRERELEASE 171
+PRERELEASE 172
PRERELEASE_PATCH 0
\ No newline at end of file
