pkg/analysis_server/test/lsp/hover_test.dart

// Copyright (c) 2018, 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.

import 'package:analysis_server/lsp_protocol/protocol.dart';
import 'package:analysis_server/src/lsp/constants.dart';
import 'package:analyzer/src/test_utilities/test_code_format.dart';
import 'package:analyzer_testing/package_config_file_builder.dart';
import 'package:test/test.dart';
import 'package:test_reflective_loader/test_reflective_loader.dart';

import '../tool/lsp_spec/matchers.dart';
import '../utils/test_code_extensions.dart';
import 'server_abstract.dart';

void main() {
  defineReflectiveSuite(() {
    defineReflectiveTests(HoverTest);
  });
}

@reflectiveTest
class HoverTest extends AbstractLspAnalysisServerTest {
  /// Checks whether the correct types of documentation are returned in a Hover
  /// based on [preference].
  Future<void> assertDocumentation(
    String? preference, {
    required bool includesSummary,
    required bool includesFull,
  }) async {
    var code = TestCode.parse('''
    /// Summary.
    ///
    /// Full.
    class ^A {}
    ''');

    await provideConfig(initialize, {'documentation': ?preference});
    await openFile(mainFileUri, code.code);
    await workspaceAnalysisComplete();
    var hover = await getHover(mainFileUri, code.position.position);
    var hoverContents = _getStringContents(hover!);

    if (includesSummary) {
      expect(hoverContents, contains('Summary.'));
    } else {
      expect(hoverContents, isNot(contains('Summary.')));
    }

    if (includesFull) {
      expect(hoverContents, contains('Full.'));
    } else {
      expect(hoverContents, isNot(contains('Full.')));
    }
  }

  Future<void> assertMarkdownContents(String content, Matcher matcher) async {
    setHoverContentFormat([MarkupKind.Markdown]);

    var code = TestCode.parse(content);

    await initialize();
    await openFile(mainFileUri, code.code);
    await workspaceAnalysisComplete();
    var hover = await getHover(mainFileUri, code.position.position);
    expect(hover, isNotNull);
    expect(hover!.range, equals(code.range.range));
    expect(hover.contents, isNotNull);
    var markup = _getMarkupContents(hover);
    expect(markup.kind, equals(MarkupKind.Markdown));
    expect(markup.value, matcher);
  }

  Future<void> assertNullHover(
    String content, {
    bool waitForAnalysis = false,
    bool withOpenFile = true,
  }) async {
    var code = TestCode.parse(content);

    await initialize();
    if (withOpenFile) {
      await openFile(mainFileUri, code.code);
    } else {
      newFile(mainFilePath, code.code);
      if (waitForAnalysis) {
        await pumpEventQueue(times: 5000); // Allow server to see watch event.
      }
    }
    if (waitForAnalysis) {
      await workspaceAnalysisComplete();
    }
    var hover = await getHover(mainFileUri, code.position.position);
    expect(hover, isNull);
  }

  Future<void> assertPlainTextContents(String content, Matcher matcher) async {
    setHoverContentFormat([MarkupKind.PlainText]);
    var code = TestCode.parse(content);

    await initialize();
    await openFile(mainFileUri, code.code);
    await workspaceAnalysisComplete();
    var hover = await getHover(mainFileUri, code.position.position);
    expect(hover, isNotNull);
    expect(hover!.range, equals(code.range.range));
    expect(hover.contents, isNotNull);
    var markup = _getMarkupContents(hover);
    expect(markup.kind, equals(MarkupKind.PlainText));
    expect(markup.value, matcher);
  }

  Future<void> assertStringContents(
    String content,
    Matcher matcher, {
    Uri? fileUri,
    bool waitForAnalysis = false,
    bool withOpenFile = true,
  }) async {
    fileUri ??= mainFileUri;

    var code = TestCode.parse(content);

    await initialize();
    if (withOpenFile) {
      await openFile(fileUri, code.code);
    } else {
      newFile(mainFilePath, code.code);
      if (waitForAnalysis) {
        await pumpEventQueue(times: 5000); // Allow server to see watch event.
      }
    }
    if (waitForAnalysis) {
      await workspaceAnalysisComplete();
    }
    var hover = await getHover(fileUri, code.position.position);
    expect(hover, isNotNull);
    expect(hover!.range, equals(code.range.range));
    expect(hover.contents, isNotNull);
    var contents = _getStringContents(hover);
    expect(contents, matcher);
  }

  Future<void> test_dartDoc_macros() =>
      assertStringContents(waitForAnalysis: true, '''
    /// {@template template_name}
    /// This is shared content.
    /// {@endtemplate}
    const String? foo = null;

    /// {@macro template_name}
    const String? [!f^oo2!] = null;
    ''', endsWith('This is shared content.'));

  Future<void> test_dartDocPreference_full() =>
      assertDocumentation('full', includesSummary: true, includesFull: true);

  Future<void> test_dartDocPreference_summary() => assertDocumentation(
    'summary',
    includesSummary: true,
    // Doc preferences don't apply to single-result requests so always expect
    // full docs.
    includesFull: true,
  );

  /// No preference should result in full docs.
  Future<void> test_dartDocPreference_unset() =>
      assertDocumentation(null, includesSummary: true, includesFull: true);

  Future<void> test_declaredIn_classAndLibrary() async {
    var content = '''
class A {
  String? [!a^!];
}
''';
    var expected = '''
```dart
String? a
```
Type: `String?`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_declaredIn_emptyClassName() async {
    failTestOnErrorDiagnostic = false;

    var content = '''
class {
  String? [!a^!];
}
''';
    var expected = '''
```dart
String? a
```
Type: `String?`

Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_declaredIn_nonPackage() async {
    // Files in the test folder don't have package: URIs and will show relative
    // paths instead.
    var fileUri = toUri(join(projectFolderPath, 'test', 'one_test.dart'));
    var content = '''
class A {
  String? [!a^!];
}
''';
    var expected = '''
```dart
String? a
```
Type: `String?`

Declared in `A` in *test/one_test.dart*.''';
    await assertStringContents(fileUri: fileUri, content, equals(expected));
  }

  Future<void> test_declaredIn_nonPackage_pubWorkspace() async {
    // Files in the test folder don't have package: URIs and will show relative
    // paths instead. In a Pub Workspace, this should be relative to the package
    // and not the workspace.

    newFile(join(projectFolderPath, 'pubspec.yaml'), '''
workspace:
  - pkgs/a
''');
    newFile(join(projectFolderPath, 'pkgs', 'a', 'pubspec.yaml'), '''
name: a
environment:
  sdk: ^3.7.0
''');
    var config = PackageConfigFileBuilder();
    config.add(name: 'a', rootFolder: getFolder('$projectFolderPath/pkgs/a'));
    writeTestPackageConfig2(config: config);

    var fileUri = toUri(
      join(projectFolderPath, 'pkgs', 'a', 'test', 'one_test.dart'),
    );
    var content = '''
class A {
  String? [!a^!];
}
''';
    var expected = '''
```dart
String? a
```
Type: `String?`

Declared in `A` in *test/one_test.dart*.''';
    await assertStringContents(fileUri: fileUri, content, equals(expected));
  }

  Future<void> test_declaredIn_onlyLibrary() async {
    var content = '''
class A {}

[!A^!]? a;
''';
    var expected = '''
```dart
class A
```
Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_constructor_named() async {
    var content = '''
class A {
  A.named();
}
void f() {
  A a = [!.nam^ed()!];
}
''';
    var expected = '''
```dart
(new) A.named()
```
Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_constructor_named_const() async {
    var content = '''
class A {
  const A.named();
}
void f() {
  const A a = [!.nam^ed()!];
}
''';
    var expected = '''
```dart
(const) A.named()
```
Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_constructor_unnamed() async {
    var content = '''
class A {}
void f() {
  A a = [!.ne^w()!];
}
''';
    var expected = '''
```dart
(new) A()
```
Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_constructor_unnamed_const() async {
    var content = '''
class A {
  const A();
}
void f() {
  const A a = [!.ne^w()!];
}
''';
    var expected = '''
```dart
(const) A()
```
Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_method() async {
    var content = '''
class A {
  static A method() => A();
}
void f() {
  A a = .[!meth^od!]();
}
''';
    var expected = '''
```dart
A method()
```
Type: `A Function()`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_method_subclass() async {
    var content = '''
class A {
  static B method() => B();
}

class B extends A {}

void g(A a) {}

void f() {
  g(.[!met^hod!]());
}
''';
    var expected = '''
```dart
B method()
```
Type: `B Function()`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_propertyAccess() async {
    var content = '''
class A {
  static A field = A();
}
void f() {
  A a = .[!fie^ld!];
}
''';
    var expected = '''
```dart
A get field
```
Type: `A`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_propertyAccess_enum() async {
    var content = '''
enum A { one }
void f() {
  A a = .[!on^e!];
}
''';
    var expected = '''
```dart
A get one
```
Type: `A`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_dotShorthand_propertyAccess_extensionType() async {
    var content = '''
extension type A(int x) {
  static A get getter => A(1);
}
void f() {
  A a = .[!gette^r!];
}
''';
    var expected = '''
```dart
A get getter
```
Type: `A`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_enum_member() async {
    var content = '''
enum MyEnum { one }

void f() {
  MyEnum.[!o^ne!];
}
''';
    var expected = '''
```dart
MyEnum get one
```
Type: `MyEnum`

Declared in `MyEnum` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_enum_member_declaration() async {
    var content = '''
enum E {
  /// Docs
  [!on^e!]
}
''';
    var expected = '''
```dart
E one
```
Type: `E`

Declared in `E` in *package:test/main.dart*.

---
Docs''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_enum_values() async {
    var content = '''
enum MyEnum { one }

void f() {
  MyEnum.[!va^lues!];
}
''';
    var expected = '''
```dart
List<MyEnum> get values
```
Type: `List<MyEnum>`

Declared in `MyEnum` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_field_underscore() async {
    var content = '''
class A {
  int _ = 1;
  int f() => [!^_!];
}
''';
    var expected = '''
```dart
int get _
```
Type: `int`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_forLoop_declaredVariable() async {
    var content = '''
void f() {
  for (var [!ii^i!] in <String>[]) {}
}
''';
    var expected = '''
```dart
String iii
```
Type: `String`

Declared in `f` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_forLoop_variableReference() async {
    var content = '''
void f() {
  for (var iii in <String>[]) {
    print([!ii^i!]);
  }
}
''';
    var expected = '''
```dart
String iii
```
Type: `String`

Declared in `f` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_function_startOfParameterList() => assertStringContents('''
    /// This is a function.
    void [!abc!]^() {}
    ''', contains('This is a function.'));

  Future<void> test_function_startOfTypeParameterList() =>
      assertStringContents('''
    /// This is a function.
    void [!abc!]^<T>(T a) {}
    ''', contains('This is a function.'));

  Future<void> test_functionType_assignedToVariable() async {
    var content = '''
void f(int p1, int p2) {
  var [!^x!] = f;
}
''';

    var expected =
        '''
```dart
void Function(int p1, int p2) x
```
Type: `void Function(int, int)`

Declared in `f` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expected));
  }

  Future<void> test_functionType_constructorTearOff() async {
    var content = '''
class C {
  C(int p1, int p2) {}
}
void f() {
  C.[!^new!];
}
''';

    var expected =
        '''
```dart
C(int p1, int p2)
```
Declared in `C` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expected));
  }

  Future<void> test_functionType_methodTearOff() async {
    var content = '''
class C {
  f(int p1, int p2) {}
}
void f(C c) {
  c.[!^f!];
}
''';

    var expected =
        '''
```dart
dynamic f(int p1, int p2)
```
Type: `dynamic Function(int, int)`

Declared in `C` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expected));
  }

  Future<void> test_functionType_parameter() async {
    var content = '''
void f(String Function(int p1, int p2) [!^x!]) {}
''';

    var expected =
        '''
```dart
String Function(int p1, int p2) x
```
Type: `String Function(int, int)`

Declared in `f` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expected));
  }

  Future<void> test_functionType_typedef() async {
    failTestOnAnyErrorNotification = false;

    var content = '''
typedef [!^Foo!] = String Function(int p1, int p2);
''';

    var expected =
        '''
```dart
typedef Foo = String Function(int p1, int p2)
```
Declared in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expected));
  }

  Future<void> test_hover_bad_position() async {
    await initialize();
    await openFile(mainFileUri, '');
    await expectLater(
      () => getHover(mainFileUri, Position(line: 999, character: 999)),
      throwsA(isResponseError(ServerErrorCodes.invalidFileLineCol)),
    );
  }

  Future<void> test_import_alias_dart() async {
    var content = '''
import 'dart:core' as [!l^ib!];
''';
    var expected = '''
```dart
import 'dart:core' as lib;
```
Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_import_alias_interpolation() async {
    var content = '''
// ignore: uri_with_interpolation
import '\$bug.dart' as [!l^ib!];
const bug = 'bug';
''';
    var expected = '''
```dart
import '<unknown>' as lib;
```
Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_import_alias_multiple_equal() async {
    newFile('/home/my_project/lib/lib.dart', '''
/// This is a string.
library my.lib;
''');
    var content = '''
import 'dart:math' as lib;
import 'lib.dart' as [!l^ib!];
''';
    var expected = '''
```dart
import 'dart:math' as lib;
import 'lib.dart' as lib;
```
Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_import_alias_package() async {
    newFile('/home/my_project/lib/lib.dart', '''
/// This is a string.
library my.lib;
''');
    var content = '''
import 'package:test/lib.dart' as [!l^ib!];
''';
    var expected = '''
```dart
import 'package:test/lib.dart' as lib;
```
Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_import_alias_project() async {
    newFile('/home/my_project/lib/lib.dart', '''
''');
    var content = '''
import 'lib.dart' as [!l^ib!];
''';
    var expected = '''
```dart
import 'lib.dart' as lib;
```
Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_import_prefix() async {
    newFile('/home/my_project/lib/lib.dart', '''
/// This is a string.
library my.lib;
class C {}
''');
    var content = '''
import 'lib.dart' as lib;
[!li^b!].C? c;
''';
    var expected = '''
```dart
import 'lib.dart' as lib;
```
Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_localVariable_wildcard() async {
    var content = '''
f() {
  int [!^_!] = 0;
}
''';
    await assertNullHover(content);
  }

  Future<void> test_localVariable_wildcard_beforeFeature() async {
    var content = '''
// @dart=3.6
f() {
  int [!^_!] = 0;
}
''';
    var expected = '''
```dart
int _
```
Type: `int`

Declared in `f` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_markdown_isFormattedForDisplay() async {
    var content = '''
    /// This is a string.
    ///
    /// {@template foo}
    /// With some [refs] and some
    /// [links](https://www.dartlang.org/)
    /// {@endtemplate foo}
    ///
    /// ```dart sample
    /// print();
    /// ```
    String? [!a^bc!];
    ''';

    var expectedHoverContent =
        '''
```dart
String? abc
```
Type: `String?`

Declared in *package:test/main.dart*.

---
This is a string.

With some [refs] and some
[links](https://www.dartlang.org/)

```dart
print();
```
    '''
            .trim();

    await assertMarkdownContents(content, equals(expectedHoverContent));
  }

  Future<void> test_markdown_simple() => assertMarkdownContents('''
    /// This is a string.
    String [!a^bc!] = '';
    ''', contains('This is a string.'));

  Future<void> test_method_callMethod_invocation() async {
    var content = '''
/// f doc.
void f(int i) {
  f.[!call^!](1);
}
''';
    var expected = '''
```dart
void f(int i)
```
Type: `void Function(int)`

Declared in *package:test/main.dart*.

---
f doc.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_method_callMethod_tearOff() async {
    var content = '''
/// f doc.
void f(int i) {
  f.[!call^!];
}
''';
    var expected = '''
```dart
void f(int i)
```
Type: `void Function(int)`

Declared in *package:test/main.dart*.

---
f doc.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_method_mixin_onImplementation() async {
    var content = '''
abstract class A {
  /// Documentation for [f].
  void f();
}

abstract class B implements A {}

mixin M on B {
  @override
  void [!f^!]() {}
}
''';
    await assertStringContents(content, contains('Documentation for [f].'));
  }

  Future<void> test_method_startOfParameterList() => assertStringContents('''
    class A {
      /// This is a method.
      void [!abc!]^() {}
    }
    ''', contains('This is a method.'));

  Future<void> test_method_startOfTypeParameterList() =>
      assertStringContents('''
    class A {
      /// This is a method.
      String [!abc!]^<T>(T a) => '';
    }
    ''', contains('This is a method.'));

  Future<void> test_method_underscore() async {
    var content = '''
class A {
  int _() => 1;
  int f() => [!^_!]();
}
''';
    var expected = '''
```dart
int _()
```
Type: `int Function()`

Declared in `A` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_noElement() async {
    var code = TestCode.parse('''
    String? abc;

    ^

    int? a;
    ''');

    await initialize();
    await openFile(mainFileUri, code.code);
    var hover = await getHover(mainFileUri, code.position.position);
    expect(hover, isNull);
  }

  Future<void> test_nonDartFile() async {
    await initialize();
    await openFile(pubspecFileUri, simplePubspecContent);
    var hover = await getHover(pubspecFileUri, startOfDocPos);
    expect(hover, isNull);
  }

  Future<void> test_nullableTypes() async {
    var content = '''
    String? [!a^bc!];
    ''';

    var expectedHoverContent =
        '''
```dart
String? abc
```
Type: `String?`

Declared in *package:test/main.dart*.
    '''
            .trim();

    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_parameter_wildcard() async {
    var content = '''
f(int [!^_!]) { }
''';
    await assertNullHover(content);
  }

  Future<void> test_parameter_wildcard_beforeFeature() async {
    var content = '''
// @dart=3.6
f(int [!^_!]) { }
''';
    var expected = '''
```dart
int _
```
Type: `int`

Declared in `f` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_pattern_assignment_left() => assertStringContents('''
void f(String a, String b) {
  (b, [!a^!]) = (a, b);
}
    ''', contains('Type: `String`'));

  Future<void> test_pattern_assignment_list() => assertStringContents('''
void f(List<int> x, num a) {
  [[!a^!]] = x;
}
    ''', contains('num a'));

  Future<void> test_pattern_assignment_right() => assertStringContents('''
void f(String a, String b) {
  (b, a) = ([!a^!], b);
}
    ''', contains('Type: `String`'));

  Future<void> test_pattern_cast_typeName() => assertStringContents('''
void f((num, Object) record) {
  var (i as int, s as [!St^ring!]) = record;
}
    ''', contains('class String'));

  Future<void> test_pattern_map() => assertStringContents('''
void f(x) {
  switch (x) {
    case {0: [!Str^ing!] a}:
      break;
  }
}
    ''', contains('class String'));

  Future<void> test_pattern_map_typeArguments() => assertStringContents('''
void f(x) {
  switch (x) {
    case <int, [!Str^ing!]>{0: var a}:
      break;
  }
}
    ''', contains('class String'));

  Future<void> test_pattern_nullAssert() => assertStringContents('''
void f((int?, int?) position) {
  var ([!x^!]!, y!) = position;
}
    ''', contains('Type: `int`'));

  Future<void> test_pattern_nullCheck() => assertStringContents('''
void f(String? maybeString) {
  switch (maybeString) {
    case var [!s^!]?:
  }
}
    ''', contains('Type: `String`'));

  Future<void> test_pattern_object_fieldName() => assertStringContents('''
double calculateArea(Shape shape) =>
  switch (shape) {
    Square([!leng^th!]: var l) => l * l,
  };

sealed class Shape { }
class Square extends Shape {
  /// The length.
  double get length => 0;
}
    ''', allOf([contains('double get length'), contains('The length.')]));

  Future<void> test_pattern_object_typeName() => assertStringContents('''
double calculateArea(Shape shape) =>
  switch (shape) {
    [!Squ^are!](length: var l) => l * l,
  };

sealed class Shape { }
/// A square.
class Square extends Shape {
  double get length => 0;
}
    ''', contains('A square.'));

  Future<void> test_pattern_record_fieldName() => assertStringContents('''
void f(({int foo}) x, num a) {
  ([!fo^o!]: a,) = x;
}
    ''', contains('Type: `int`'));

  Future<void> test_pattern_record_fieldValue() => assertStringContents('''
void f(({int foo}) x, num a) {
  (foo: [!a^!],) = x;
}
    ''', contains('Type: `num`'));

  Future<void> test_pattern_record_variable() => assertStringContents('''
void f(({int foo}) x, num a) {
  (foo: a,) = [!x^!];
}
    ''', contains('Type: `({int foo})`'));

  Future<void> test_pattern_relational_variable() => assertStringContents('''
String f(int char) {
  const zero = 0;
  return switch (char) {
    == [!ze^ro!] => 'zero',
    _ => '',
  };
}
    ''', contains('Type: `int`'));

  Future<void> test_pattern_variable_wildcard() => assertStringContents('''
void f() {
  var a = (1, 2);
  var ([!^_!], _) = a;
}
    ''', contains('Type: `int`'));

  Future<void> test_pattern_variable_wildcard_annotated() =>
      assertStringContents('''
void f() {
  var a = (1, 2);
  var (int [!^_!], _) = a;
}
    ''', contains('Type: `int`'));

  Future<void> test_plainText_simple() => assertPlainTextContents('''
    /// This is a string.
    String? [!a^bc!];
    ''', contains('This is a string.'));

  Future<void> test_promotedTypes() async {
    var content = '''
void f(aaa) {
  if (aaa is String) {
    print([!aa^a!]);
  }
}
''';

    var expectedHoverContent = '''
```dart
dynamic aaa
```
Type: `String`

Declared in `f` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_range_binaryOperator() async {
    var content = '''
var i = 1;
var a = i [!+^!] i;
''';
    var expected = '''
```dart
num +(num other)
```
Declared in `num` in *dart:core*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_range_compoundAssignment() async {
    var content = '''
void f(int i) {
  i [!+=^!] 1;
}
''';
    var expected = '''
```dart
num +(num other)
```
Declared in `num` in *dart:core*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_range_conditional_colon() async {
    var content = '''
var i = 1;
int f(bool a, int x) {
  return a
    ? x
    [!:^!] x + 1;
}
''';
    var expected = 'Type: `int`';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_range_conditional_question() async {
    var content = '''
var i = 1;
int f(bool a, int x) {
  return a
    [!?^!] x
    : x + 1;
}
''';
    var expected = 'Type: `int`';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_range_multiLineConstructorCall() => assertStringContents('''
    final a = new [!Str^ing.fromCharCodes!]([
      1,
      2,
    ]);
    ''', contains('String.fromCharCodes('));

  Future<void> test_range_postfix() async {
    var content = '''
int f(int i) {
  return i[!+^+!];
}
''';
    var expected = '''
```dart
num +(num other)
```
Declared in `num` in *dart:core*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_range_prefix() async {
    var content = '''
int f(int i) {
  return [!+^+!]i;
}
''';
    var expected = '''
```dart
num +(num other)
```
Declared in `num` in *dart:core*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_recordLiteral_named() => assertStringContents(r'''
void f(({int f1, int f2}) r) {
  r.[!f^1!];
}
    ''', contains('Type: `int`'));

  Future<void> test_recordLiteral_positional() => assertStringContents(r'''
void f((int, int) r) {
  r.[!$^1!];
}
    ''', contains('Type: `int`'));

  Future<void> test_recordType_parameter() => assertStringContents('''
Object f(([!dou^ble!], double) param) {
  return (1.0, 1.0);
}
    ''', contains('class double'));

  Future<void> test_recordType_return() => assertStringContents('''
([!dou^ble!], double) f() {
  return (1.0, 1.0);
}
    ''', contains('class double'));

  Future<void> test_signatureFormatting_multiLine() => assertStringContents(
    '''
    class Foo {
      Foo(String arg1, String arg2, [String? arg3]);
    }

    void f() {
      var a = [!Fo^o!]('', '');
    }
    ''',
    startsWith('''
```dart
(new) Foo(
  String arg1,
  String arg2, [
  String? arg3,
])
```'''),
  );

  Future<void> test_signatureFormatting_singleLine() => assertStringContents(
    '''
    class Foo {
      Foo(String a, String b);
    }

    void f() {
      var a = [!Fo^o!]('', '');
    }
    ''',
    startsWith('''
```dart
(new) Foo(String a, String b)
```'''),
  );

  Future<void> test_staticType_field() async {
    var content = '''
class A<T> {
  late final T? myField;
}

final data = A<String?>().[!myF^ield!];
    ''';

    var expectedHoverContent =
        '''
```dart
String? get myField
```
Type: `String?`

Declared in `A` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_staticType_getter() async {
    var content = '''
class A {
  String get myGetter => '';
}

final data = A().[!myG^etter!];
    ''';

    var expectedHoverContent =
        '''
```dart
String get myGetter
```
Type: `String`

Declared in `A` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_staticType_getter_generic() async {
    var content = '''
class A<T> {
  late final T? myField;
  T? get myGetter => myField;
}

final data = A<String?>().[!myG^etter!];
    ''';

    var expectedHoverContent =
        '''
```dart
String? get myGetter
```
Type: `String?`

Declared in `A` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_staticType_setter() async {
    var content = '''
class A {
  set mySetter(String value) {}
}

void f() {
  A().[!myS^etter!] = '';
}
    ''';

    var expectedHoverContent =
        '''
```dart
set mySetter(String value)
```
Type: `String`

Declared in `A` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_staticType_setter_generic() async {
    var content = '''
class A<T> {
  set mySetter(T value) {}
}

void f() {
  A<String>().[!myS^etter!] = '';
}
    ''';

    var expectedHoverContent =
        '''
```dart
set mySetter(String value)
```
Type: `String`

Declared in `A` in *package:test/main.dart*.
'''
            .trim();

    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_string_noDocComment() async {
    var content = '''
    String? [!a^bc!];
    ''';

    var expectedHoverContent =
        '''
```dart
String? abc
```
Type: `String?`

Declared in *package:test/main.dart*.
    '''
            .trim();

    await assertStringContents(content, equals(expectedHoverContent));
  }

  Future<void> test_string_reflectsLatestEdits() async {
    var original = TestCode.parse('''
    /// Original string.
    String? [!a^bc!];
    ''');
    var updated = TestCode.parse('''
    /// Updated string.
    String? [!a^bc!];
    ''');

    await initialize();
    await openFile(mainFileUri, original.code);
    var hover = await getHover(mainFileUri, original.position.position);
    expect(hover, isNotNull);
    var contents = _getStringContents(hover!);
    expect(contents, contains('Original'));

    await replaceFile(222, mainFileUri, updated.code);
    hover = await getHover(mainFileUri, updated.position.position);
    expect(hover, isNotNull);
    contents = _getStringContents(hover!);
    expect(contents, contains('Updated'));
  }

  Future<void> test_string_simple() async {
    var content = '''
/// This is a string.
String? [!a^bc!];
''';
    var expected = '''
```dart
String? abc
```
Type: `String?`

Declared in *package:test/main.dart*.

---
This is a string.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_superFormalParameter_fromField() async {
    var content = '''
class A {
  /// The field a.
  int a;

  A(this.a);
}

class B extends A {
  B(super.a);
}

class C extends B {
  C(super.[!^a!]);
}
''';
    var expected = '''
```dart
int a
```
Type: `int`

Declared in `new` in `C` in *package:test/main.dart*.

---
The field a.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_superFormalParameter_notFromChainedConstructor() async {
    var content = '''
class A {
  /// The constructor a.
  A(int a);
}

class B extends A {
  B(super.[!^a!]);
}
''';
    var expected = '''
```dart
int a
```
Type: `int`

Declared in `new` in `B` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_this() async {
    var content = '''
class A {
  void a() {
    [!thi^s!].a();
  }
}
''';
    var expected = '''
Type: `A`''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_this_promoted() async {
    var content = '''
class A {
  void a() {
    if (this is B) {
      [!thi^s!].b();
    }
  }
}

class B extends A {
  void b() {}
}
''';
    var expected = '''
Type: `B`''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_topLevelFunction_underscore() async {
    var content = '''
int _() => 1;
int f() => [!^_!]();
''';
    var expected = '''
```dart
int _()
```
Type: `int Function()`

Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_topLevelVariable_underscore() async {
    var content = '''
int _ = 1;
int f() => [!^_!];
''';
    var expected = '''
```dart
int get _
```
Type: `int`

Declared in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_tryCatch_error() async {
    var content = '''
void foo() {
  try {} on Exception catch ([!err^or!], stack) {}
}
''';
    var expected = '''
```dart
Exception error
```
Type: `Exception`

Declared in `foo` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_tryCatch_stack() async {
    var content = '''
void foo() {
  try {} on Exception catch (error, [!stac^k!]) {}
}
''';
    var expected = '''
```dart
StackTrace stack
```
Type: `StackTrace`

Declared in `foo` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_class() async {
    var content = '''
class C<T> {
  late [!^T!] f;
}
''';
    var expected = '''
```dart
<T>
```
Declared in `C` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_closureInFunction() async {
    var content = '''
void foo() {
  <O extends int>() {
    late [!^O!] o;
  };
}
''';
    var expected = '''
```dart
<O extends int>
```
Declared in `<unnamed>` in `foo` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_function() async {
    var content = '''
void foo<T, O extends T>() {
  foo<T, [!^O!]>();
}
''';
    var expected = '''
```dart
<O extends T>
```
Declared in `foo` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_functionInFunction() async {
    var content = '''
void foo() {
  void f<O extends int>() {
    late [!^O!] o;
  }
}
''';
    var expected = '''
```dart
<O extends int>
```
Declared in `f` in `foo` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_functionTyped_parameter() async {
    var content = '''
void foo([!^T!] Function<T extends int>() f) {}
''';
    var expected = '''
```dart
<T extends int>
```
Declared in `f` in `foo` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_functionTyped_return() async {
    var content = '''
[!^T!] Function<T extends int>(T p) f() => <T extends int>(T p) => p;
''';
    var expected = '''
```dart
<T extends int>
```
Declared in `f` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_functionTyped_typedef() async {
    var content = '''
typedef F = [!^T!] Function<T extends int>();
''';
    var expected = '''
```dart
<T extends int>
```
Declared in `F` in *package:test/main.dart*.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_typeParameter_wildcard() async {
    var content = '''
class C<[!^_!]> {}
''';
    await assertNullHover(content);
  }

  Future<void> test_unnamed_library_directive() async {
    var content = '''
/// This is a string.
[!lib^rary!];
''';
    var expected = '''
```dart
library package:test/main.dart
```
Declared in *package:test/main.dart*.

---
This is a string.''';
    await assertStringContents(content, equals(expected));
  }

  Future<void> test_unopenFile() async {
    var content = '''
/// This is a string.
String? [!a^bc!];
''';
    var expected = '''
```dart
String? abc
```
Type: `String?`

Declared in *package:test/main.dart*.

---
This is a string.''';
    await assertStringContents(withOpenFile: false, content, equals(expected));
  }

  MarkupContent _getMarkupContents(Hover hover) {
    return hover.contents.map(
      (t1) => t1,
      (t2) => throw 'Hover contents were String, not MarkupContent',
    );
  }

  String _getStringContents(Hover hover) {
    return hover.contents.map(
      (t1) => throw 'Hover contents were MarkupContent, not String',
      (t2) => t2,
    );
  }
}