Report DUPLICATE_DEFINITION for 'values' in enums.

Change-Id: I0df2f7286e8913b3a323fd19bb18a8d77f27bbe6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/232025
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

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

@@ -2788,6 +2788,17 @@ class EnumElementImpl extends AbstractClassElementImpl {
     return super.typeParameters;
   }
 
+  ConstFieldElementImpl? get valuesField {
+    for (var field in fields) {
+      if (field is ConstFieldElementImpl &&
+          field.name == 'values' &&
+          field.isSyntheticEnumField) {
+        return field;
+      }
+    }
+    return null;
+  }
+
   @override
   void appendTo(ElementDisplayStringBuilder builder) {
     builder.writeEnumElement(this);

pkg/analyzer/lib/src/error/duplicate_definition_verifier.dart

@@ -53,6 +53,11 @@ class DuplicateDefinitionVerifier {
     var staticGetters = <String, Element>{};
     var staticSetters = <String, Element>{};
 
+    var valuesField = enumElement.valuesField;
+    if (valuesField != null) {
+      staticGetters['values'] = valuesField;
+    }
+
     for (EnumConstantDeclaration constant in node.constants) {
       _checkDuplicateIdentifier(staticGetters, constant.name);
     }

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

@@ -329,6 +329,26 @@ f(,[]) {}
 
 @reflectiveTest
 class DuplicateDefinitionEnumTest extends PubPackageResolutionTest {
+  test_constant() async {
+    await assertErrorsInCode(r'''
+enum E {
+  foo, foo
+}
+''', [
+      error(CompileTimeErrorCode.DUPLICATE_DEFINITION, 16, 3),
+    ]);
+  }
+
+  test_constant_values() async {
+    await assertErrorsInCode(r'''
+enum E {
+  values
+}
+''', [
+      error(CompileTimeErrorCode.DUPLICATE_DEFINITION, 11, 6),
+    ]);
+  }
+
   test_instance_field_field() async {
     await assertErrorsInCode(r'''
 enum E {
@@ -491,6 +511,48 @@ enum E {
     ]);
   }
 
+  test_static_constant_field() async {
+    await assertErrorsInCode(r'''
+enum E {
+  foo;
+  static int foo = 0;
+}
+''', [
+      error(CompileTimeErrorCode.DUPLICATE_DEFINITION, 29, 3),
+    ]);
+  }
+
+  test_static_constant_getter() async {
+    await assertErrorsInCode(r'''
+enum E {
+  foo;
+  static int get foo => 0;
+}
+''', [
+      error(CompileTimeErrorCode.DUPLICATE_DEFINITION, 33, 3),
+    ]);
+  }
+
+  test_static_constant_method() async {
+    await assertErrorsInCode(r'''
+enum E {
+  foo;
+  static void foo() {}
+}
+''', [
+      error(CompileTimeErrorCode.DUPLICATE_DEFINITION, 30, 3),
+    ]);
+  }
+
+  test_static_constant_setter() async {
+    await assertNoErrorsInCode(r'''
+enum E {
+  foo;
+  static set foo(int _) {}
+}
+''');
+  }
+
   test_static_field_field() async {
     await assertErrorsInCode(r'''
 enum E {
@@ -527,6 +589,17 @@ enum E {
     ]);
   }
 
+  test_static_field_values() async {
+    await assertErrorsInCode(r'''
+enum E {
+  v;
+  static int values = 0;
+}
+''', [
+      error(CompileTimeErrorCode.DUPLICATE_DEFINITION, 27, 6),
+    ]);
+  }
+
   test_static_fieldFinal_getter() async {
     await assertErrorsInCode(r'''
 enum E {

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

@@ -98,16 +98,6 @@ enum E {
     ]);
   }
 
-  /// TODO(scheglov) this is wrong, we should get an error
-  test_enum_field_static() async {
-    await assertNoErrorsInCode(r'''
-enum E {
-  v;
-  static int values = 0;
-}
-''');
-  }
-
   test_enum_getter() async {
     await assertErrorsInCode(r'''
 enum E {