DeCo. Report nonRedirectingGenerativeConstructorWithPrimary

Bug: #61701
Change-Id: Ie6f221be25b3029a60de4960be8307930358314c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/464244
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

Author: scheglov

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

@@ -1277,6 +1277,8 @@ NON_GENERATIVE_IMPLICIT_CONSTRUCTOR:
   status: needsFix
   notes: |-
     Suggest generative constructors that could be invoked.
+NON_REDIRECTING_GENERATIVE_CONSTRUCTOR_WITH_PRIMARY:
+  status: needsEvaluation
 NON_SYNC_FACTORY:
   status: needsFix
   notes: |-

pkg/analyzer/lib/src/diagnostic/diagnostic.g.dart

@@ -12280,6 +12280,22 @@ const DiagnosticWithoutArguments nonPositiveArrayDimension =
       expectedTypes: [],
     );
 
+/// No parameters.
+const DiagnosticWithoutArguments
+nonRedirectingGenerativeConstructorWithPrimary = DiagnosticWithoutArgumentsImpl(
+  name: 'NON_REDIRECTING_GENERATIVE_CONSTRUCTOR_WITH_PRIMARY',
+  problemMessage:
+      "Classes with primary constructors can't have non-redirecting generative "
+      "constructors.",
+  correctionMessage:
+      "Try making the constructor redirect to the primary constructor, or "
+      "remove the primary constructor.",
+  type: DiagnosticType.COMPILE_TIME_ERROR,
+  uniqueName:
+      'CompileTimeErrorCode.NON_REDIRECTING_GENERATIVE_CONSTRUCTOR_WITH_PRIMARY',
+  expectedTypes: [],
+);
+
 /// A code indicating that the activity is set to be non resizable.
 ///
 /// No parameters.

pkg/analyzer/lib/src/diagnostic/diagnostic_code_values.g.dart

@@ -797,6 +797,7 @@ const List<DiagnosticCode> diagnosticCodeValues = [
   diag.nonNullableEqualsParameter,
   diag.nonPartOfDirectiveInPart,
   diag.nonPositiveArrayDimension,
+  diag.nonRedirectingGenerativeConstructorWithPrimary,
   diag.nonResizableActivity,
   diag.nonSizedTypeArgument,
   diag.nonStringLiteralAsUri,

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

@@ -640,6 +640,7 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
         }
         _checkForUndefinedConstructorInInitializerImplicit(node);
         _checkForReturnInGenerativeConstructor(node);
+        _checkForNonRedirectingGenerativeConstructorWithPrimary(node);
         super.visitConstructorDeclaration(node);
       },
       isAsynchronous: fragment.isAsynchronous,
@@ -4688,6 +4689,27 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
     );
   }
 
+  void _checkForNonRedirectingGenerativeConstructorWithPrimary(
+    ConstructorDeclaration node,
+  ) {
+    var enclosingClass = _enclosingClass;
+    if (enclosingClass == null ||
+        enclosingClass is ExtensionTypeElement ||
+        enclosingClass.constructors.none((c) => c.isPrimary)) {
+      return;
+    }
+
+    if (node.factoryKeyword != null ||
+        node.initializers.any((i) => i is RedirectingConstructorInvocation)) {
+      return;
+    }
+
+    diagnosticReporter.atConstructorDeclaration(
+      node,
+      diag.nonRedirectingGenerativeConstructorWithPrimary,
+    );
+  }
+
   /// Verify that the given method [declaration] of operator `[]=`, has `void`
   /// return type.
   ///

pkg/analyzer/messages.yaml

@@ -12134,6 +12134,11 @@ CompileTimeErrorCode:
 
       class B implements A {}
       ```
+  NON_REDIRECTING_GENERATIVE_CONSTRUCTOR_WITH_PRIMARY:
+    parameters: none
+    problemMessage: "Classes with primary constructors can't have non-redirecting generative constructors."
+    correctionMessage: "Try making the constructor redirect to the primary constructor, or remove the primary constructor."
+    hasPublishedDocs: false
   NON_SYNC_FACTORY:
     parameters: none
     problemMessage: "Factory bodies can't use 'async', 'async*', or 'sync*'."

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

@@ -0,0 +1,119 @@
+// Copyright (c) 2025, 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/diagnostic/diagnostic.dart' as diag;
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import '../dart/resolution/context_collection_resolution.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(NonRedirectingGenerativeConstructorWithPrimaryTest);
+  });
+}
+
+@reflectiveTest
+class NonRedirectingGenerativeConstructorWithPrimaryTest
+    extends PubPackageResolutionTest {
+  test_class_factory() async {
+    await assertNoErrorsInCode(r'''
+class C(int x) {
+  factory C.named() => C(0);
+}
+''');
+  }
+
+  test_class_generative_nonRedirecting() async {
+    await assertErrorsInCode(
+      r'''
+class C(int x) {
+  C.named();
+}
+''',
+      [error(diag.nonRedirectingGenerativeConstructorWithPrimary, 19, 7)],
+    );
+  }
+
+  test_class_generative_redirectingToNonPrimary() async {
+    await assertErrorsInCode(
+      r'''
+class C(int x) {
+  C.named1() : this.named2();
+  C.named2();
+}
+''',
+      [error(diag.nonRedirectingGenerativeConstructorWithPrimary, 49, 8)],
+    );
+  }
+
+  test_class_generative_redirectingToPrimary() async {
+    await assertNoErrorsInCode(r'''
+class C(int x) {
+  C.named() : this(0);
+}
+''');
+  }
+
+  test_class_noPrimaryConstructor() async {
+    await assertNoErrorsInCode(r'''
+class C {
+  C.named();
+}
+''');
+  }
+
+  test_enum_factory() async {
+    await assertNoErrorsInCode(r'''
+enum E(int x) {
+  v(0);
+  factory E.named() => E.v;
+}
+''');
+  }
+
+  test_enum_generative_nonRedirecting() async {
+    await assertErrorsInCode(
+      r'''
+enum E(int x) {
+  v(0);
+  const E.named();
+}
+''',
+      [
+        error(diag.nonRedirectingGenerativeConstructorWithPrimary, 32, 7),
+        error(diag.unusedElement, 34, 5),
+      ],
+    );
+  }
+
+  test_enum_generative_redirectingToPrimary() async {
+    await assertErrorsInCode(
+      r'''
+enum E(int x) {
+  v(0);
+  const E.named(int x) : this(x);
+}
+''',
+      [error(diag.unusedElement, 34, 5)],
+    );
+  }
+
+  test_enum_noPrimaryConstructor() async {
+    await assertNoErrorsInCode(r'''
+enum E {
+  v;
+  const E();
+}
+''');
+  }
+
+  test_extensionType_generative_nonRedirecting() async {
+    // Extension types can have non-redirecting generative constructors.
+    await assertNoErrorsInCode(r'''
+extension type E(int x) {
+  E.named(this.x);
+}
+''');
+  }
+}

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

@@ -672,6 +672,8 @@ import 'non_native_function_type_argument_to_pointer_test.dart'
     as non_native_function_type_argument_to_pointer;
 import 'non_nullable_equals_parameter_test.dart' as non_null_equals_parameters;
 import 'non_positive_array_dimension_test.dart' as non_positive_array_dimension;
+import 'non_redirecting_generative_constructor_with_primary_test.dart'
+    as non_redirecting_generative_constructor_with_primary;
 import 'non_sized_type_argument_test.dart' as non_sized_type_argument;
 import 'non_type_as_type_argument_test.dart' as non_type_as_type_argument;
 import 'non_type_in_catch_clause_test.dart' as non_type_in_catch_clause;
@@ -1384,6 +1386,7 @@ main() {
     non_native_function_type_argument_to_pointer.main();
     non_null_equals_parameters.main();
     non_positive_array_dimension.main();
+    non_redirecting_generative_constructor_with_primary.main();
     non_sized_type_argument.main();
     non_type_as_type_argument.main();
     non_type_in_catch_clause.main();