Augment. Report AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT

Change-Id: I5590b68366a12129e42e19e26ac3ec4fa8330149
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/372221
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/lib/src/services/correction/error_fix_status.yaml

@@ -203,6 +203,8 @@ CompileTimeErrorCode.ASSIGNMENT_TO_TYPE:
   status: noFix
 CompileTimeErrorCode.ASYNC_FOR_IN_WRONG_CONTEXT:
   status: hasFix
+CompileTimeErrorCode.AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT:
+  status: needsEvaluation
 CompileTimeErrorCode.AUGMENTATION_MODIFIER_EXTRA:
   status: hasFix
 CompileTimeErrorCode.AUGMENTATION_MODIFIER_MISSING:

pkg/analyzer/lib/src/dart/analysis/driver.dart

@@ -95,7 +95,7 @@ import 'package:meta/meta.dart';
 // TODO(scheglov): Clean up the list of implicitly analyzed files.
 class AnalysisDriver {
   /// The version of data format, should be incremented on every format change.
-  static const int DATA_VERSION = 367;
+  static const int DATA_VERSION = 368;
 
   /// The number of exception contexts allowed to write. Once this field is
   /// zero, we stop writing any new exception contexts in this process.

pkg/analyzer/lib/src/dart/element/element.dart

@@ -317,6 +317,14 @@ class ClassElementImpl extends ClassOrMixinElementImpl
     super.fields = fields;
   }
 
+  bool get hasExtendsClause {
+    return hasModifier(Modifier.HAS_EXTENDS_CLAUSE);
+  }
+
+  set hasExtendsClause(bool value) {
+    setModifier(Modifier.HAS_EXTENDS_CLAUSE, value);
+  }
+
   bool get hasGenerativeConstConstructor {
     return constructors.any((c) => !c.isFactory && c.isConst);
   }
@@ -5463,6 +5471,9 @@ enum Modifier {
   /// Indicates that the pseudo-modifier 'get' was applied to the element.
   GETTER,
 
+  /// Indicates that this class has an explicit `extends` clause.
+  HAS_EXTENDS_CLAUSE,
+
   /// A flag used for libraries indicating that the variable has an explicit
   /// initializer.
   HAS_INITIALIZER,

pkg/analyzer/lib/src/error/codes.g.dart

@@ -214,6 +214,17 @@ class CompileTimeErrorCode extends AnalyzerErrorCode {
     hasPublishedDocs: true,
   );
 
+  static const CompileTimeErrorCode
+      AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT = CompileTimeErrorCode(
+    'AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT',
+    "The augmentation has an 'extends' clause, but an augmentation target "
+        "already includes an 'extends' clause and it isn't allowed to be "
+        "repeated or changed.",
+    correctionMessage:
+        "Try removing the 'extends' clause, either here or in the augmentation "
+        "target.",
+  );
+
   ///  Parameters:
   ///  0: the lexeme of the modifier.
   static const CompileTimeErrorCode AUGMENTATION_MODIFIER_EXTRA =

pkg/analyzer/lib/src/error/error_code_values.g.dart

@@ -63,6 +63,7 @@ const List<ErrorCode> errorCodeValues = [
   CompileTimeErrorCode.ASSIGNMENT_TO_METHOD,
   CompileTimeErrorCode.ASSIGNMENT_TO_TYPE,
   CompileTimeErrorCode.ASYNC_FOR_IN_WRONG_CONTEXT,
+  CompileTimeErrorCode.AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT,
   CompileTimeErrorCode.AUGMENTATION_MODIFIER_EXTRA,
   CompileTimeErrorCode.AUGMENTATION_MODIFIER_MISSING,
   CompileTimeErrorCode.AUGMENTATION_OF_DIFFERENT_DECLARATION_KIND,

pkg/analyzer/lib/src/generated/error_verifier.dart

@@ -459,6 +459,11 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
         augmentationElement: element,
       );
 
+      _checkClassAugmentationTargetAlreadyHasExtendsClause(
+        node: node,
+        augmentationTarget: element.augmentationTarget,
+      );
+
       _isInNativeClass = node.nativeClause != null;
 
       var augmented = element.augmented;
@@ -1704,6 +1709,36 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
     );
   }
 
+  void _checkClassAugmentationTargetAlreadyHasExtendsClause({
+    required ClassDeclarationImpl node,
+    required ClassElementImpl? augmentationTarget,
+  }) {
+    var extendsClause = node.extendsClause;
+    if (extendsClause == null) {
+      return;
+    }
+
+    while (augmentationTarget != null) {
+      if (augmentationTarget.hasExtendsClause) {
+        errorReporter.atToken(
+          extendsClause.extendsKeyword,
+          CompileTimeErrorCode.AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT,
+          contextMessages: [
+            DiagnosticMessageImpl(
+              filePath: augmentationTarget.source.fullName,
+              offset: augmentationTarget.nameOffset,
+              length: augmentationTarget.nameLength,
+              message: 'The extends clause is included here.',
+              url: null,
+            ),
+          ],
+        );
+        return;
+      }
+      augmentationTarget = augmentationTarget.augmentationTarget;
+    }
+  }
+
   /// Checks the class for problems with the superclass, mixins, or implemented
   /// interfaces.
   ///

pkg/analyzer/lib/src/summary2/element_builder.dart

@@ -102,6 +102,7 @@ class ElementBuilder extends ThrowingAstVisitor<void> {
       element.isAbstract = true;
       element.isSealed = true;
     }
+    element.hasExtendsClause = node.extendsClause != null;
     element.metadata = _buildAnnotations(node.metadata);
     _setCodeRange(element, node);
     _setDocumentation(element, node);

pkg/analyzer/lib/src/summary2/element_flags.dart

@@ -7,22 +7,24 @@ import 'package:analyzer/src/summary2/data_reader.dart';
 import 'package:analyzer/src/summary2/data_writer.dart';
 
 class ClassElementFlags {
-  static const int _isAbstract = 1 << 0;
-  static const int _isAugmentation = 1 << 1;
-  static const int _isBase = 1 << 2;
-  static const int _isFinal = 1 << 3;
-  static const int _isInterface = 1 << 4;
-  static const int _isMacro = 1 << 5;
-  static const int _isMixinApplication = 1 << 6;
-  static const int _isMixinClass = 1 << 7;
-  static const int _isSealed = 1 << 8;
-  static const int _isSimplyBounded = 1 << 9;
+  static const int _hasExtendsClause = 1 << 0;
+  static const int _isAbstract = 1 << 1;
+  static const int _isAugmentation = 1 << 2;
+  static const int _isBase = 1 << 3;
+  static const int _isFinal = 1 << 4;
+  static const int _isInterface = 1 << 5;
+  static const int _isMacro = 1 << 6;
+  static const int _isMixinApplication = 1 << 7;
+  static const int _isMixinClass = 1 << 8;
+  static const int _isSealed = 1 << 9;
+  static const int _isSimplyBounded = 1 << 10;
 
   static void read(
     SummaryDataReader reader,
     ClassElementImpl element,
   ) {
     var byte = reader.readUInt30();
+    element.hasExtendsClause = (byte & _hasExtendsClause) != 0;
     element.isAbstract = (byte & _isAbstract) != 0;
     element.isAugmentation = (byte & _isAugmentation) != 0;
     element.isBase = (byte & _isBase) != 0;
@@ -40,6 +42,7 @@ class ClassElementFlags {
     ClassElementImpl element,
   ) {
     var result = 0;
+    result |= element.hasExtendsClause ? _hasExtendsClause : 0;
     result |= element.isAbstract ? _isAbstract : 0;
     result |= element.isAugmentation ? _isAugmentation : 0;
     result |= element.isBase ? _isBase : 0;

pkg/analyzer/messages.yaml

@@ -1131,6 +1131,9 @@ CompileTimeErrorCode:
         }
       }
       ```
+  AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT:
+    problemMessage: The augmentation has an 'extends' clause, but an augmentation target already includes an 'extends' clause and it isn't allowed to be repeated or changed.
+    correctionMessage: Try removing the 'extends' clause, either here or in the augmentation target.
   AUGMENTATION_MODIFIER_EXTRA:
     problemMessage: The augmentation has the '{0}' modifier that the declaration doesn't have.
     correctionMessage: Try removing the '{0}' modifier, or adding it to the declaration.

pkg/analyzer/test/src/diagnostics/augmentation_extends_clause_already_present_test.dart

@@ -0,0 +1,81 @@
+// Copyright (c) 2024, 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:analyzer/src/error/codes.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import '../dart/resolution/context_collection_resolution.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(AugmentationExtendsClauseAlreadyPresentTest);
+  });
+}
+
+@reflectiveTest
+class AugmentationExtendsClauseAlreadyPresentTest
+    extends PubPackageResolutionTest {
+  test_alreadyPresent() async {
+    var a = newFile('$testPackageLibPath/a.dart', r'''
+import augment 'test.dart';
+
+class A {}
+
+class B extends A {};
+''');
+
+    await assertErrorsInCode(r'''
+augment library 'a.dart';
+
+augment class B extends A {}
+''', [
+      error(CompileTimeErrorCode.AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT,
+          43, 7,
+          contextMessages: [message(a, 47, 1)]),
+    ]);
+  }
+
+  test_alreadyPresent2() async {
+    var a = newFile('$testPackageLibPath/a.dart', r'''
+import augment 'b.dart';
+import augment 'test.dart';
+
+class A {}
+
+class B extends A {};
+''');
+
+    newFile('$testPackageLibPath/b.dart', r'''
+augment library 'a.dart';
+
+augment class B {}
+''');
+
+    await assertErrorsInCode(r'''
+augment library 'a.dart';
+
+augment class B extends A {}
+''', [
+      error(CompileTimeErrorCode.AUGMENTATION_EXTENDS_CLAUSE_ALREADY_PRESENT,
+          43, 7,
+          contextMessages: [message(a, 72, 1)]),
+    ]);
+  }
+
+  test_notPresent() async {
+    newFile('$testPackageLibPath/a.dart', r'''
+import augment 'test.dart';
+
+class A {}
+
+class B {};
+''');
+
+    await assertNoErrorsInCode(r'''
+augment library 'a.dart';
+
+augment class B extends A {}
+''');
+  }
+}

pkg/analyzer/test/src/diagnostics/test_all.dart

@@ -38,6 +38,8 @@ import 'assignment_to_type_test.dart' as assignment_to_type;
 import 'async_for_in_wrong_context_test.dart' as async_for_in_wrong_context;
 import 'async_keyword_used_as_identifier_test.dart'
     as async_keyword_used_as_identifier;
+import 'augmentation_extends_clause_already_present_test.dart'
+    as augmentation_extends_clause_already_present;
 import 'augmentation_modifier_extra_test.dart' as augmentation_modifier_extra;
 import 'augmentation_modifier_missing_test.dart'
     as augmentation_modifier_missing;
@@ -943,6 +945,7 @@ main() {
     assignment_to_type.main();
     async_for_in_wrong_context.main();
     async_keyword_used_as_identifier.main();
+    augmentation_extends_clause_already_present.main();
     augmentation_modifier_extra.main();
     augmentation_modifier_missing.main();
     augmentation_of_different_declaration_kind.main();