Fix #28120, strong mode allows field overrides

pkg/analyzer/test/src/task/strong/checker_test.dart

 // Copyright (c) 2015, 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.src.task.strong.checker_test;
 
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'strong_test_helper.dart';
 
@@ skipping 708 matching lines @@
 class C extends B {}
 
 class Base {
   B f1;
   B f2;
   B f3;
   B f4;
 }
 
 class Child extends Base {
-  /*error:INVALID_FIELD_OVERRIDE,error:INVALID_METHOD_OVERRIDE*/A f1; // invalid for getter
-  /*error:INVALID_FIELD_OVERRIDE,error:INVALID_METHOD_OVERRIDE*/C f2; // invalid for setter
-  /*error:INVALID_FIELD_OVERRIDE*/var f3;
-  /*error:INVALID_FIELD_OVERRIDE,error:INVALID_METHOD_OVERRIDE*/dynamic f4;
+  /*error:INVALID_METHOD_OVERRIDE*/A f1; // invalid for getter
+  /*error:INVALID_METHOD_OVERRIDE*/C f2; // invalid for setter
+  var f3;
+  /*error:INVALID_METHOD_OVERRIDE*/dynamic f4;
 }
 
 class Child2 implements Base {
   /*error:INVALID_METHOD_OVERRIDE*/A f1; // invalid for getter
   /*error:INVALID_METHOD_OVERRIDE*/C f2; // invalid for setter
   var f3;
   /*error:INVALID_METHOD_OVERRIDE*/dynamic f4;
 }
 ''');
   }
 
   test_fieldGetterOverride() async {
     await checkFile('''
 class A {}
 class B extends A {}
 class C extends B {}
 
 abstract class Base {
   B f1;
   B f2;
   B f3;
   B f4;
 }
 
 class Child extends Base {
-  /*error:INVALID_FIELD_OVERRIDE,error:INVALID_METHOD_OVERRIDE*/A get f1 => null;
-  /*error:INVALID_FIELD_OVERRIDE*/C get f2 => null;
-  /*error:INVALID_FIELD_OVERRIDE*/get f3 => null;
-  /*error:INVALID_FIELD_OVERRIDE,error:INVALID_METHOD_OVERRIDE*/dynamic get f4 => null;
+  /*error:INVALID_METHOD_OVERRIDE*/A get f1 => null;
+  C get f2 => null;
+  get f3 => null;
+  /*error:INVALID_METHOD_OVERRIDE*/dynamic get f4 => null;
 }
 
 class /*error:NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_FOUR*/Child2 implements Base {
   /*error:INVALID_METHOD_OVERRIDE*/A get f1 => null;
   C get f2 => null;
   get f3 => null;
   /*error:INVALID_METHOD_OVERRIDE*/dynamic get f4 => null;
 }
 ''');
   }
 
   test_fieldOverride_fuzzyArrows() async {
     await checkFile('''
 typedef void ToVoid<T>(T x);
 class F {
   final ToVoid<dynamic> f = null;
   final ToVoid<int> g = null;
 }
 
 class G extends F {
-  /*error:INVALID_FIELD_OVERRIDE*/final ToVoid<int> f = null;
-  /*error:INVALID_FIELD_OVERRIDE, error:INVALID_METHOD_OVERRIDE*/final ToVoid<dynamic> g = null;
+  final ToVoid<int> f = null;
+  /*error:INVALID_METHOD_OVERRIDE*/final ToVoid<dynamic> g = null;
 }
 
 class H implements F {
   final ToVoid<int> f = null;
   /*error:INVALID_METHOD_OVERRIDE*/final ToVoid<dynamic> g = null;
 }
  ''');
   }
 
   test_fieldOverride_virtual() async {
@@ skipping 14 matching lines @@
   set x(int v) {}
 }
 class OverrideWithField extends C {
   int x;
 
   // expose the hidden storage slot
   int get superX => super.x;
   set superX(int v) { super.x = v; }
 }
 class VirtualNotInherited extends OverrideWithField {
-  /*error:INVALID_FIELD_OVERRIDE*/int x;
+  int x;
 }
     ''');
   }
 
   test_fieldSetterOverride() async {
     await checkFile('''
 class A {}
 class B extends A {}
 class C extends B {}
 
 class Base {
   B f1;
   B f2;
   B f3;
   B f4;
   B f5;
 }
 
 class Child extends Base {
-  /*error:INVALID_FIELD_OVERRIDE*/B get f1 => null;
-  /*error:INVALID_FIELD_OVERRIDE*/B get f2 => null;
-  /*error:INVALID_FIELD_OVERRIDE*/B get f3 => null;
-  /*error:INVALID_FIELD_OVERRIDE*/B get f4 => null;
-  /*error:INVALID_FIELD_OVERRIDE*/B get f5 => null;
+  B get f1 => null;
+  B get f2 => null;
+  B get f3 => null;
+  B get f4 => null;
+  B get f5 => null;
 
-  /*error:INVALID_FIELD_OVERRIDE*/void set f1(A value) {}
-  /*error:INVALID_FIELD_OVERRIDE,error:INVALID_METHOD_OVERRIDE*/void set f2(C value) {}
-  /*error:INVALID_FIELD_OVERRIDE*/void set f3(value) {}
-  /*error:INVALID_FIELD_OVERRIDE*/void set f4(dynamic value) {}
-  /*error:INVALID_FIELD_OVERRIDE*/set f5(B value) {}
+  void set f1(A value) {}
+  /*error:INVALID_METHOD_OVERRIDE*/void set f2(C value) {}
+  void set f3(value) {}
+  void set f4(dynamic value) {}
+  set f5(B value) {}
 }
 
 class Child2 implements Base {
   B get f1 => null;
   B get f2 => null;
   B get f3 => null;
   B get f4 => null;
   B get f5 => null;
 
   void set f1(A value) {}
@@ skipping 1624 matching lines @@
   test_invalidOverrides_childOverride() async {
     await checkFile('''
 class A {}
 class B {}
 
 class Base {
     A f;
 }
 
 class T1 extends Base {
-  /*warning:MISMATCHED_GETTER_AND_SETTER_TYPES_FROM_SUPERTYPE, error:INVALID_FIELD_OVERRIDE, error:INVALID_METHOD_OVERRIDE*/B get f => null;
+  /*warning:MISMATCHED_GETTER_AND_SETTER_TYPES_FROM_SUPERTYPE,error:INVALID_METHOD_OVERRIDE*/B get f => null;
 }
 
 class T2 extends Base {
-  /*warning:MISMATCHED_GETTER_AND_SETTER_TYPES_FROM_SUPERTYPE, error:INVALID_FIELD_OVERRIDE, error:INVALID_METHOD_OVERRIDE*/set f(
+  /*warning:MISMATCHED_GETTER_AND_SETTER_TYPES_FROM_SUPERTYPE,error:INVALID_METHOD_OVERRIDE*/set f(
       B b) => null;
 }
 
 class T3 extends Base {
-  /*error:INVALID_FIELD_OVERRIDE, error:INVALID_METHOD_OVERRIDE*/final B
+  /*error:INVALID_METHOD_OVERRIDE*/final B
       /*warning:FINAL_NOT_INITIALIZED*/f;
 }
 class T4 extends Base {
   // two: one for the getter one for the setter.
-  /*error:INVALID_FIELD_OVERRIDE, error:INVALID_METHOD_OVERRIDE, error:INVALID_METHOD_OVERRIDE*/B f;
+  /*error:INVALID_METHOD_OVERRIDE, error:INVALID_METHOD_OVERRIDE*/B f;
 }
 
 class /*error:NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_ONE*/T5 implements Base {
   /*warning:MISMATCHED_GETTER_AND_SETTER_TYPES_FROM_SUPERTYPE, error:INVALID_METHOD_OVERRIDE*/B get f => null;
 }
 
 class /*error:NON_ABSTRACT_CLASS_INHERITS_ABSTRACT_MEMBER_ONE*/T6 implements Base {
   /*warning:MISMATCHED_GETTER_AND_SETTER_TYPES_FROM_SUPERTYPE, error:INVALID_METHOD_OVERRIDE*/set f(B b) => null;
 }
 
@@ skipping 81 matching lines @@
 
 class Grandparent {
     m(A a) {}
     int x;
 }
 class Parent extends Grandparent {
 }
 
 class Test extends Parent {
     /*error:INVALID_METHOD_OVERRIDE*/m(B a) {}
-    /*error:INVALID_FIELD_OVERRIDE*/int x;
+    int x;
 }
 ''');
   }
 
   test_invalidOverrides_mixinOverrideOfInterface() async {
     await checkFile('''
 class A {}
 class B {}
 
 abstract class I {
@@ skipping 24 matching lines @@
     m(B a) {}
 }
 
 class M2 {
     int x;
 }
 
 class /*error:INCONSISTENT_METHOD_INHERITANCE*/T1 extends Base
     with /*error:INVALID_METHOD_OVERRIDE_FROM_MIXIN*/M1 {}
 class /*error:INCONSISTENT_METHOD_INHERITANCE*/T2 extends Base
-    with /*error:INVALID_METHOD_OVERRIDE_FROM_MIXIN*/M1, /*error:INVALID_FIELD_OVERRIDE*/M2 {}
+    with /*error:INVALID_METHOD_OVERRIDE_FROM_MIXIN*/M1, M2 {}
 class /*error:INCONSISTENT_METHOD_INHERITANCE*/T3 extends Base
-    with /*error:INVALID_FIELD_OVERRIDE*/M2, /*error:INVALID_METHOD_OVERRIDE_FROM_MIXIN*/M1 {}
+    with M2, /*error:INVALID_METHOD_OVERRIDE_FROM_MIXIN*/M1 {}
 ''');
   }
 
   test_invalidOverrides_mixinOverrideToMixin() async {
     await checkFile('''
 class A {}
 class B {}
 
 class Base {
 }
 
 class M1 {
     m(B a) {}
     int x;
 }
 
 class M2 {
     m(A a) {}
     int x;
 }
 
 class /*error:INCONSISTENT_METHOD_INHERITANCE*/T1 extends Base
     with M1,
-    /*error:INVALID_METHOD_OVERRIDE_FROM_MIXIN,error:INVALID_FIELD_OVERRIDE*/M2 {}
+    /*error:INVALID_METHOD_OVERRIDE_FROM_MIXIN*/M2 {}
 ''');
   }
 
   test_invalidOverrides_noDuplicateMixinOverride() async {
     // This is a regression test for a bug in an earlier implementation were
     // names were hiding errors if the first mixin override looked correct,
     // but subsequent ones did not.
     await checkFile('''
 class A {}
 class B {}
@@ skipping 592 matching lines @@
 class Base {
   var f1;
   var _f2;
   var _f3;
   get _f4 => null;
 
   int _m1() => null;
 }
 
 class GrandChild extends main.Child {
-  /*error:INVALID_FIELD_OVERRIDE*/var _f2;
-  /*error:INVALID_FIELD_OVERRIDE*/var _f3;
+  var _f2;
+  var _f3;
   var _f4;
 
   /*error:INVALID_METHOD_OVERRIDE*/String _m1() => null;
 }
 ''',
         name: '/helper.dart');
     await checkFile('''
 import 'helper.dart' as helper;
 
 class Child extends helper.Base {
-  /*error:INVALID_FIELD_OVERRIDE*/var f1;
+  var f1;
   var _f2;
   var _f4;
 
   String _m1() => null;
 }
 ''');
   }
 
   test_proxy() async {
     await checkFile(r'''
@@ skipping 822 matching lines @@
 class CheckerTest_Driver extends CheckerTest {
   @override
   bool get enableNewAnalysisDriver => true;
 
   @failingTest
   @override
   test_covariantOverride_fields() async {
     await super.test_covariantOverride_fields();
   }
 }