Remove false positive from override hint (issue 27046)

pkg/analyzer/test/generated/non_hint_code_test.dart

 // Copyright (c) 2016, 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.
 
 library analyzer.test.generated.non_hint_code_test;
 
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 
 import '../reflective_tests.dart';
@@ skipping 470 matching lines @@
   bool operator ==(x) { return x; }
   get hashCode => 0;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
   void test_overrideOnNonOverridingField_inInterface() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   int get a => 0;
   void set b(_) {}
   int c;
 }
 class B implements A {
   @override
   final int a = 1;
   @override
   int b;
   @override
   int c;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
   void test_overrideOnNonOverridingField_inSuperclass() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   int get a => 0;
   void set b(_) {}
   int c;
 }
 class B extends A {
   @override
   final int a = 1;
   @override
   int b;
   @override
   int c;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
   void test_overrideOnNonOverridingGetter_inInterface() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   int get m => 0;
 }
 class B implements A {
   @override
   int get m => 1;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
   void test_overrideOnNonOverridingGetter_inSuperclass() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   int get m => 0;
 }
 class B extends A {
   @override
   int get m => 1;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
   void test_overrideOnNonOverridingMethod_inInterface() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   int m() => 0;
 }
 class B implements A {
   @override
   int m() => 1;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
   void test_overrideOnNonOverridingMethod_inSuperclass() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   int m() => 0;
 }
 class B extends A {
   @override
   int m() => 1;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
+  void test_overrideOnNonOverridingMethod_inSuperclass_abstract() {
+    Source source = addSource(r'''
+abstract class A {
+  int m();
+}
+class B extends A {
+  @override
+  int m() => 1;
+}''');
+    computeLibrarySourceErrors(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_overrideOnNonOverridingSetter_inInterface() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   set m(int x) {}
 }
 class B implements A {
   @override
   set m(int x) {}
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
   void test_overrideOnNonOverridingSetter_inSuperclass() {
     Source source = addSource(r'''
-library dart.core;
-const override = null;
 class A {
   set m(int x) {}
 }
 class B extends A {
   @override
   set m(int x) {}
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
@@ skipping 695 matching lines @@
 
   void test_import_valid_outside_lib() {
     cacheSource("/myproj/pubspec.yaml", "");
     cacheSource("/myproj/web/other.dart", "");
     Source source =
         addNamedSource("/myproj/lib2/test.dart", "import '../web/other.dart';");
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
   }
 }