diff --git a/pkg/analyzer/lib/error/listener.dart b/pkg/analyzer/lib/error/listener.dart
index ba45f03..6209775 100644
--- a/pkg/analyzer/lib/error/listener.dart
+++ b/pkg/analyzer/lib/error/listener.dart
@@ -165,6 +165,12 @@
         arguments[i] = argument.getDisplayString(
           withNullability: isNonNullableByDefault,
         );
+      } else if (!(argument is String ||
+          argument is DartType ||
+          argument is int ||
+          argument is Uri)) {
+        throw ArgumentError(
+            'Tried to format an error using ${argument.runtimeType}');
       }
     }
   }
diff --git a/pkg/analyzer/lib/src/dart/resolver/function_reference_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/function_reference_resolver.dart
index 7c8bc9f..dedb7b5 100644
--- a/pkg/analyzer/lib/src/dart/resolver/function_reference_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/function_reference_resolver.dart
@@ -64,7 +64,10 @@
         _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS_CONSTRUCTOR,
           typeArguments,
-          [function.constructorName.type2.name, function.constructorName.name!],
+          [
+            function.constructorName.type2.name.toSource(),
+            function.constructorName.name!.name
+          ],
         );
         _resolve(node: node, rawType: function.staticType);
       }
diff --git a/pkg/analyzer/lib/src/error/best_practices_verifier.dart b/pkg/analyzer/lib/src/error/best_practices_verifier.dart
index 85441dc..2e4ffc1 100644
--- a/pkg/analyzer/lib/src/error/best_practices_verifier.dart
+++ b/pkg/analyzer/lib/src/error/best_practices_verifier.dart
@@ -482,9 +482,10 @@
           // always named, so we can safely assume
           // `overriddenElement.enclosingElement.name` is non-`null`.
           _errorReporter.reportErrorForNode(
-              HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER,
-              field.name,
-              [field.name, overriddenElement.enclosingElement.name!]);
+              HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER, field.name, [
+            field.name.name,
+            overriddenElement.enclosingElement.displayName
+          ]);
         }
         if (!_invalidAccessVerifier._inTestDirectory) {
           _checkForAssignmentOfDoNotStore(field.initializer);
@@ -671,7 +672,7 @@
         _errorReporter.reportErrorForNode(
             HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER,
             node.name,
-            [node.name, overriddenElement.enclosingElement.name!]);
+            [node.name.name, overriddenElement.enclosingElement.displayName]);
       }
 
       super.visitMethodDeclaration(node);
diff --git a/pkg/analyzer/lib/src/error/type_arguments_verifier.dart b/pkg/analyzer/lib/src/error/type_arguments_verifier.dart
index c2f2f09..9db6af2 100644
--- a/pkg/analyzer/lib/src/error/type_arguments_verifier.dart
+++ b/pkg/analyzer/lib/src/error/type_arguments_verifier.dart
@@ -499,7 +499,8 @@
       NodeList<TypeAnnotation> arguments, ErrorCode errorCode) {
     for (TypeAnnotation type in arguments) {
       if (type is NamedType && type.type is TypeParameterType) {
-        _errorReporter.reportErrorForNode(errorCode, type, [type.name]);
+        _errorReporter
+            .reportErrorForNode(errorCode, type, [type.name.toSource()]);
       }
     }
   }
diff --git a/pkg/analyzer/lib/src/generated/element_resolver.dart b/pkg/analyzer/lib/src/generated/element_resolver.dart
index 717940b..e64547d 100644
--- a/pkg/analyzer/lib/src/generated/element_resolver.dart
+++ b/pkg/analyzer/lib/src/generated/element_resolver.dart
@@ -438,7 +438,7 @@
         _errorReporter.reportErrorForNode(
             CompileTimeErrorCode.UNDEFINED_CONSTRUCTOR_IN_INITIALIZER,
             node,
-            [superType, name]);
+            [superType, name.name]);
       } else {
         _errorReporter.reportErrorForNode(
             CompileTimeErrorCode.UNDEFINED_CONSTRUCTOR_IN_INITIALIZER_DEFAULT,
diff --git a/pkg/analyzer/lib/src/generated/error_verifier.dart b/pkg/analyzer/lib/src/generated/error_verifier.dart
index ffac3f2..e140ee8 100644
--- a/pkg/analyzer/lib/src/generated/error_verifier.dart
+++ b/pkg/analyzer/lib/src/generated/error_verifier.dart
@@ -795,7 +795,7 @@
         if (parameterType is FunctionType &&
             parameterType.returnType.isDynamic) {
           errorReporter.reportErrorForNode(LanguageCode.IMPLICIT_DYNAMIC_RETURN,
-              node.identifier, [node.identifier]);
+              node.identifier, [node.identifier.name]);
         }
       }
 
@@ -2089,12 +2089,12 @@
       errorReporter.reportErrorForNode(
           CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR,
           name,
-          [className, name]);
+          [className.toSource(), name.name]);
     } else {
       errorReporter.reportErrorForNode(
           CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT,
           constructorName,
-          [className]);
+          [className.toSource()]);
     }
   }
 
@@ -2593,7 +2593,7 @@
       }
       // Parameters associated with a variable always have a name, so we can
       // safely rely on [id] being non-`null`.
-      errorReporter.reportErrorForNode(errorCode, node, [id!]);
+      errorReporter.reportErrorForNode(errorCode, node, [id!.toSource()]);
     }
   }
 
@@ -2739,18 +2739,18 @@
         errorReporter.reportErrorForNode(
             CompileTimeErrorCode.INITIALIZER_FOR_NON_EXISTENT_FIELD,
             initializer,
-            [fieldName]);
+            [fieldName.name]);
       } else if (staticElement.isStatic) {
         errorReporter.reportErrorForNode(
             CompileTimeErrorCode.INITIALIZER_FOR_STATIC_FIELD,
             initializer,
-            [fieldName]);
+            [fieldName.name]);
       }
     } else {
       errorReporter.reportErrorForNode(
           CompileTimeErrorCode.INITIALIZER_FOR_NON_EXISTENT_FIELD,
           initializer,
-          [fieldName]);
+          [fieldName.name]);
       return;
     }
   }
@@ -3328,12 +3328,12 @@
       errorReporter.reportErrorForNode(
           CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR,
           name,
-          [className, name]);
+          [className.toSource(), name.name]);
     } else {
       errorReporter.reportErrorForNode(
           CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT,
           constructorName,
-          [className]);
+          [className.toSource()]);
     }
   }
 
@@ -3651,8 +3651,9 @@
 
       if (treatedAsDouble) {
         // Suggest the nearest valid double (as a BigInt for printing reasons).
-        extraErrorArgs
-            .add(BigInt.from(IntegerLiteralImpl.nearestValidDouble(lexeme)));
+        extraErrorArgs.add(
+            BigInt.from(IntegerLiteralImpl.nearestValidDouble(lexeme))
+                .toString());
       }
 
       errorReporter.reportErrorForNode(
@@ -4063,7 +4064,7 @@
       errorReporter.reportErrorForNode(
           CompileTimeErrorCode.TYPE_ANNOTATION_DEFERRED_CLASS,
           type,
-          [type.name]);
+          [type.name.toSource()]);
     }
   }
 
diff --git a/pkg/analyzer/lib/src/generated/ffi_verifier.dart b/pkg/analyzer/lib/src/generated/ffi_verifier.dart
index 4d6223c..517eabc 100644
--- a/pkg/analyzer/lib/src/generated/ffi_verifier.dart
+++ b/pkg/analyzer/lib/src/generated/ffi_verifier.dart
@@ -108,11 +108,11 @@
         return;
       }
       if (typename.ffiClass != null) {
-        _errorReporter.reportErrorForNode(
-            subtypeOfFfiCode, typename, [node.name, typename.name]);
+        _errorReporter.reportErrorForNode(subtypeOfFfiCode, typename,
+            [node.name.name, typename.name.toSource()]);
       } else if (typename.isCompoundSubtype) {
-        _errorReporter.reportErrorForNode(
-            subtypeOfStructCode, typename, [node.name, typename.name]);
+        _errorReporter.reportErrorForNode(subtypeOfStructCode, typename,
+            [node.name.name, typename.name.toSource()]);
       }
     }
 
@@ -133,7 +133,7 @@
 
     if (inCompound && node.declaredElement!.typeParameters.isNotEmpty) {
       _errorReporter.reportErrorForNode(
-          FfiCode.GENERIC_STRUCT_SUBCLASS, node.name, [node.name]);
+          FfiCode.GENERIC_STRUCT_SUBCLASS, node.name, [node.name.name]);
     }
     super.visitClassDeclaration(node);
   }
diff --git a/pkg/analyzer/test/src/dart/resolution/function_reference_test.dart b/pkg/analyzer/test/src/dart/resolution/function_reference_test.dart
index fc226d1..a2dab45 100644
--- a/pkg/analyzer/test/src/dart/resolution/function_reference_test.dart
+++ b/pkg/analyzer/test/src/dart/resolution/function_reference_test.dart
@@ -311,13 +311,33 @@
 var x = A.foo<int>;
 ''', [
       error(CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS_CONSTRUCTOR, 42,
-          5),
+          5,
+          messageContains: ["'A.foo'"]),
     ]);
 
     assertFunctionReference(findNode.functionReference('A.foo<int>;'),
         findElement.constructor('foo'), 'dynamic');
   }
 
+  test_constructorReference_prefixed() async {
+    await assertErrorsInCode('''
+import 'dart:async' as a;
+var x = a.Future.delayed<int>;
+''', [
+      error(CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS_CONSTRUCTOR, 50,
+          5,
+          messageContains: ["'a.Future.delayed'"]),
+    ]);
+    assertFunctionReference(
+        findNode.functionReference('a.Future.delayed<int>;'),
+        findElement
+            .import('dart:async')
+            .importedLibrary!
+            .getType('Future')!
+            .getNamedConstructor('delayed'),
+        'dynamic');
+  }
+
   test_dynamicTyped() async {
     await assertErrorsInCode('''
 dynamic i = 1;
diff --git a/pkg/analyzer/test/src/diagnostics/const_with_undefined_constructor_test.dart b/pkg/analyzer/test/src/diagnostics/const_with_undefined_constructor_test.dart
index ee5737d..90bd671 100644
--- a/pkg/analyzer/test/src/diagnostics/const_with_undefined_constructor_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/const_with_undefined_constructor_test.dart
@@ -24,7 +24,23 @@
   return const A.noSuchConstructor();
 }
 ''', [
-      error(CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR, 48, 17),
+      error(CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR, 48, 17,
+          messageContains: ["class 'A'", "constructor 'noSuchConstructor'"]),
+    ]);
+  }
+
+  test_named_prefixed() async {
+    await assertErrorsInCode(r'''
+import 'dart:async' as a;
+f() {
+  return const a.Future.noSuchConstructor();
+}
+''', [
+      error(CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR, 56, 17,
+          messageContains: [
+            "class 'a.Future'",
+            "constructor 'noSuchConstructor'"
+          ]),
     ]);
   }
 
@@ -53,7 +69,26 @@
 }
 ''', [
       error(
-          CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT, 51, 1),
+          CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT, 51, 1,
+          messageContains: ["'A'"]),
+    ]);
+  }
+
+  test_unnamed_prefixed() async {
+    newFile('$testPackageLibPath/lib1.dart', content: '''
+class A {
+  const A.name();
+}
+''');
+    await assertErrorsInCode(r'''
+import 'lib1.dart' as lib1;
+f() {
+  return const lib1.A();
+}
+''', [
+      error(
+          CompileTimeErrorCode.CONST_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT, 49, 6,
+          messageContains: ["'lib1.A'"]),
     ]);
   }
 }
diff --git a/pkg/analyzer/test/src/diagnostics/generic_struct_subclass_test.dart b/pkg/analyzer/test/src/diagnostics/generic_struct_subclass_test.dart
index 68e338d..f154d5d 100644
--- a/pkg/analyzer/test/src/diagnostics/generic_struct_subclass_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/generic_struct_subclass_test.dart
@@ -22,7 +22,7 @@
   external Pointer notEmpty;
 }
 ''', [
-      error(FfiCode.GENERIC_STRUCT_SUBCLASS, 25, 1),
+      error(FfiCode.GENERIC_STRUCT_SUBCLASS, 25, 1, messageContains: ["'S'"]),
     ]);
   }
 
@@ -33,7 +33,7 @@
   external Pointer notEmpty;
 }
 ''', [
-      error(FfiCode.GENERIC_STRUCT_SUBCLASS, 25, 1),
+      error(FfiCode.GENERIC_STRUCT_SUBCLASS, 25, 1, messageContains: ["'S'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/implicit_dynamic_field_test.dart b/pkg/analyzer/test/src/diagnostics/implicit_dynamic_field_test.dart
index fd002a6..1bfd680 100644
--- a/pkg/analyzer/test/src/diagnostics/implicit_dynamic_field_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/implicit_dynamic_field_test.dart
@@ -49,7 +49,8 @@
   final f = (<dynamic>[])[0];
 }
 ''', [
-      error(LanguageCode.IMPLICIT_DYNAMIC_FIELD, 18, 20),
+      error(LanguageCode.IMPLICIT_DYNAMIC_FIELD, 18, 20,
+          messageContains: ["'f'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/initializer_for_non_existent_field_test.dart b/pkg/analyzer/test/src/diagnostics/initializer_for_non_existent_field_test.dart
index 43361f5..e2b6231 100644
--- a/pkg/analyzer/test/src/diagnostics/initializer_for_non_existent_field_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/initializer_for_non_existent_field_test.dart
@@ -24,7 +24,20 @@
 }
 A a = const A();
 ''', [
-      error(CompileTimeErrorCode.INITIALIZER_FOR_NON_EXISTENT_FIELD, 24, 9),
+      error(CompileTimeErrorCode.INITIALIZER_FOR_NON_EXISTENT_FIELD, 24, 9,
+          messageContains: ["'x'"]),
+    ]);
+  }
+
+  test_getter() async {
+    await assertErrorsInCode('''
+class A {
+  int get x => 0;
+  A() : x = 0;
+}
+''', [
+      error(CompileTimeErrorCode.INITIALIZER_FOR_NON_EXISTENT_FIELD, 36, 5,
+          messageContains: ["'x'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/initializer_for_static_field_test.dart b/pkg/analyzer/test/src/diagnostics/initializer_for_static_field_test.dart
index 6acd087..d556c0b 100644
--- a/pkg/analyzer/test/src/diagnostics/initializer_for_static_field_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/initializer_for_static_field_test.dart
@@ -33,7 +33,8 @@
   A() : x = 0 {}
 }
 ''', [
-      error(CompileTimeErrorCode.INITIALIZER_FOR_STATIC_FIELD, 38, 5),
+      error(CompileTimeErrorCode.INITIALIZER_FOR_STATIC_FIELD, 38, 5,
+          messageContains: ["'x'"]),
     ]);
   }
 }
diff --git a/pkg/analyzer/test/src/diagnostics/invalid_override_of_non_virtual_member_test.dart b/pkg/analyzer/test/src/diagnostics/invalid_override_of_non_virtual_member_test.dart
index 10a52f8..7c31b18 100644
--- a/pkg/analyzer/test/src/diagnostics/invalid_override_of_non_virtual_member_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/invalid_override_of_non_virtual_member_test.dart
@@ -35,7 +35,8 @@
   int g = 0;
 }
 ''', [
-      error(HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER, 113, 1),
+      error(HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER, 113, 1,
+          messageContains: ["member 'g'", "in 'C'"]),
     ]);
   }
 
@@ -70,7 +71,8 @@
   int get g => 0;
 }
 ''', [
-      error(HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER, 117, 1),
+      error(HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER, 117, 1,
+          messageContains: ["member 'g'", "in 'C'"]),
     ]);
   }
 
@@ -228,7 +230,8 @@
   void f() {}
 }
 ''', [
-      error(HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER, 111, 1),
+      error(HintCode.INVALID_OVERRIDE_OF_NON_VIRTUAL_MEMBER, 111, 1,
+          messageContains: ["member 'f'", "in 'M'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_list_test.dart b/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_list_test.dart
index a47fffd..85db5dc 100644
--- a/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_list_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_list_test.dart
@@ -23,7 +23,8 @@
   }
 }
 ''', [
-      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_LIST, 39, 1),
+      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_LIST, 39, 1,
+          messageContains: ["'E'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_map_test.dart b/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_map_test.dart
index 3c75e1d..d12b1e8 100644
--- a/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_map_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_map_test.dart
@@ -23,7 +23,8 @@
   }
 }
 ''', [
-      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_MAP, 39, 1),
+      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_MAP, 39, 1,
+          messageContains: ["'E'"]),
     ]);
   }
 
@@ -45,7 +46,8 @@
   }
 }
 ''', [
-      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_MAP, 47, 1),
+      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_MAP, 47, 1,
+          messageContains: ["'E'"]),
     ]);
   }
 }
diff --git a/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_set_test.dart b/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_set_test.dart
index fe0c076..69d6881 100644
--- a/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_set_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/invalid_type_argument_in_const_set_test.dart
@@ -23,7 +23,8 @@
   }
 }
 ''', [
-      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_SET, 39, 1),
+      error(CompileTimeErrorCode.INVALID_TYPE_ARGUMENT_IN_CONST_SET, 39, 1,
+          messageContains: ["'E'"]),
     ]);
   }
 }
diff --git a/pkg/analyzer/test/src/diagnostics/new_with_undefined_constructor_test.dart b/pkg/analyzer/test/src/diagnostics/new_with_undefined_constructor_test.dart
index 4ebf06c..4a7c777 100644
--- a/pkg/analyzer/test/src/diagnostics/new_with_undefined_constructor_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/new_with_undefined_constructor_test.dart
@@ -30,7 +30,8 @@
   new A();
 }
 ''', [
-      error(CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT, 38, 1),
+      error(CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT, 38, 1,
+          messageContains: ["'A'"]),
     ]);
   }
 
@@ -47,6 +48,24 @@
     ]);
   }
 
+  test_default_prefixed() async {
+    newFile('$testPackageLibPath/lib1.dart', content: '''
+class A {
+  A.name() {}
+}
+''');
+    await assertErrorsInCode('''
+import 'lib1.dart' as lib1;
+
+f() {
+  new lib1.A();
+}
+''', [
+      error(CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR_DEFAULT, 41, 6,
+          messageContains: ["'lib1.A'"]),
+    ]);
+  }
+
   test_default_unnamedViaNew() async {
     await assertErrorsInCode('''
 class A {
@@ -102,7 +121,25 @@
   new A.name();
 }
 ''', [
-      error(CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR, 35, 4),
+      error(CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR, 35, 4,
+          messageContains: ["class 'A'", "named 'name'"]),
+    ]);
+  }
+
+  test_named_prefixed() async {
+    newFile('$testPackageLibPath/lib1.dart', content: '''
+class A {
+  A() {}
+}
+''');
+    await assertErrorsInCode('''
+import 'lib1.dart' as lib1;
+f() {
+  new lib1.A.name();
+}
+''', [
+      error(CompileTimeErrorCode.NEW_WITH_UNDEFINED_CONSTRUCTOR, 47, 4,
+          messageContains: ["class 'lib1.A'", "named 'name'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/subtype_of_ffi_class_test.dart b/pkg/analyzer/test/src/diagnostics/subtype_of_ffi_class_test.dart
index 6e19801..63d6735 100644
--- a/pkg/analyzer/test/src/diagnostics/subtype_of_ffi_class_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/subtype_of_ffi_class_test.dart
@@ -154,7 +154,18 @@
 import 'dart:ffi';
 class C implements Double {}
 ''', [
-      error(FfiCode.SUBTYPE_OF_FFI_CLASS_IN_IMPLEMENTS, 38, 6),
+      error(FfiCode.SUBTYPE_OF_FFI_CLASS_IN_IMPLEMENTS, 38, 6,
+          messageContains: ["class 'C'", "implement 'Double'"]),
+    ]);
+  }
+
+  test_Double_prefixed() async {
+    await assertErrorsInCode(r'''
+import 'dart:ffi' as ffi;
+class C implements ffi.Double {}
+''', [
+      error(FfiCode.SUBTYPE_OF_FFI_CLASS_IN_IMPLEMENTS, 45, 10,
+          messageContains: ["class 'C'", "implement 'ffi.Double'"]),
     ]);
   }
 
@@ -285,7 +296,20 @@
 ''', [
       error(CompileTimeErrorCode.MIXIN_CLASS_DECLARES_CONSTRUCTOR, 32, 6),
       error(CompileTimeErrorCode.MIXIN_INHERITS_FROM_NOT_OBJECT, 32, 6),
-      error(FfiCode.SUBTYPE_OF_FFI_CLASS_IN_WITH, 32, 6),
+      error(FfiCode.SUBTYPE_OF_FFI_CLASS_IN_WITH, 32, 6,
+          messageContains: ["class 'C'", "mix in 'Double'"]),
+    ]);
+  }
+
+  test_Double_prefixed() async {
+    await assertErrorsInCode(r'''
+import 'dart:ffi' as ffi;
+class C with ffi.Double {}
+''', [
+      error(CompileTimeErrorCode.MIXIN_CLASS_DECLARES_CONSTRUCTOR, 39, 10),
+      error(CompileTimeErrorCode.MIXIN_INHERITS_FROM_NOT_OBJECT, 39, 10),
+      error(FfiCode.SUBTYPE_OF_FFI_CLASS_IN_WITH, 39, 10,
+          messageContains: ["class 'C'", "mix in 'ffi.Double'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/subtype_of_struct_class_test.dart b/pkg/analyzer/test/src/diagnostics/subtype_of_struct_class_test.dart
index 026be64..969c1be 100644
--- a/pkg/analyzer/test/src/diagnostics/subtype_of_struct_class_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/subtype_of_struct_class_test.dart
@@ -52,7 +52,22 @@
 class C implements S {}
 ''', [
       error(FfiCode.EMPTY_STRUCT, 25, 1),
-      error(FfiCode.SUBTYPE_OF_STRUCT_CLASS_IN_IMPLEMENTS, 64, 1),
+      error(FfiCode.SUBTYPE_OF_STRUCT_CLASS_IN_IMPLEMENTS, 64, 1,
+          messageContains: ["class 'C'", "implement 'S'"]),
+    ]);
+  }
+
+  test_implements_struct_prefixed() async {
+    newFile('$testPackageLibPath/lib1.dart', content: '''
+import 'dart:ffi';
+class S extends Struct {}
+''');
+    await assertErrorsInCode(r'''
+import 'lib1.dart' as lib1;
+class C implements lib1.S {}
+''', [
+      error(FfiCode.SUBTYPE_OF_STRUCT_CLASS_IN_IMPLEMENTS, 47, 6,
+          messageContains: ["class 'C'", "implement 'lib1.S'"]),
     ]);
   }
 
@@ -78,7 +93,24 @@
 ''', [
       error(FfiCode.EMPTY_STRUCT, 25, 1),
       error(CompileTimeErrorCode.MIXIN_INHERITS_FROM_NOT_OBJECT, 58, 1),
-      error(FfiCode.SUBTYPE_OF_STRUCT_CLASS_IN_WITH, 58, 1),
+      error(FfiCode.SUBTYPE_OF_STRUCT_CLASS_IN_WITH, 58, 1,
+          messageContains: ["class 'C'", "mix in 'S'"]),
+    ]);
+  }
+
+  test_with_struct_prefixed() async {
+    newFile('$testPackageLibPath/lib1.dart', content: '''
+import 'dart:ffi';
+class S extends Struct {}
+''');
+    await assertErrorsInCode(r'''
+import 'lib1.dart' as lib1;
+
+class C with lib1.S {}
+''', [
+      error(CompileTimeErrorCode.MIXIN_INHERITS_FROM_NOT_OBJECT, 42, 6),
+      error(FfiCode.SUBTYPE_OF_STRUCT_CLASS_IN_WITH, 42, 6,
+          messageContains: ["class 'C'", "mix in 'lib1.S'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/type_annotation_deferred_class_test.dart b/pkg/analyzer/test/src/diagnostics/type_annotation_deferred_class_test.dart
index c622fb0..b432e45 100644
--- a/pkg/analyzer/test/src/diagnostics/type_annotation_deferred_class_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/type_annotation_deferred_class_test.dart
@@ -25,7 +25,8 @@
 class C<T> { const C(); }
 @C<a.D>() main () {}
 ''', [
-      error(CompileTimeErrorCode.TYPE_ANNOTATION_DEFERRED_CLASS, 77, 3),
+      error(CompileTimeErrorCode.TYPE_ANNOTATION_DEFERRED_CLASS, 77, 3,
+          messageContains: ["'a.D'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/diagnostics/undefined_constructor_in_initializer_test.dart b/pkg/analyzer/test/src/diagnostics/undefined_constructor_in_initializer_test.dart
index b951089..daee2e5 100644
--- a/pkg/analyzer/test/src/diagnostics/undefined_constructor_in_initializer_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/undefined_constructor_in_initializer_test.dart
@@ -22,7 +22,8 @@
   B() : super.named();
 }
 ''', [
-      error(CompileTimeErrorCode.UNDEFINED_CONSTRUCTOR_IN_INITIALIZER, 39, 13),
+      error(CompileTimeErrorCode.UNDEFINED_CONSTRUCTOR_IN_INITIALIZER, 39, 13,
+          messageContains: ["class 'A'", "named 'named'"]),
     ]);
   }
 
diff --git a/pkg/analyzer/test/src/task/strong/checker_test.dart b/pkg/analyzer/test/src/task/strong/checker_test.dart
index a25a5ac..ce366390 100644
--- a/pkg/analyzer/test/src/task/strong/checker_test.dart
+++ b/pkg/analyzer/test/src/task/strong/checker_test.dart
@@ -1906,13 +1906,18 @@
 var fe0 = (int x) => x as dynamic;
 var fe1 = (int x) => x;
 ''', [
-      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 12, 2),
-      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 96, 2),
+      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 12, 2,
+          messageContains: ["'f0'"]),
+      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 96, 2,
+          messageContains: ["'g0'"]),
       error(HintCode.UNUSED_ELEMENT, 96, 2),
       error(HintCode.UNUSED_ELEMENT, 126, 2),
-      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 212, 12),
-      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 304, 2),
-      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 373, 1),
+      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 212, 12,
+          messageContains: ["'m0'"]),
+      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 304, 2,
+          messageContains: ["'y0'"]),
+      error(LanguageCode.IMPLICIT_DYNAMIC_RETURN, 373, 1,
+          messageContains: ["'f'"]),
     ]);
   }
 
diff --git a/tools/VERSION b/tools/VERSION
index f87213c..2553fc6 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 15
 PATCH 0
-PRERELEASE 276
+PRERELEASE 277
 PRERELEASE_PATCH 0
\ No newline at end of file