[nnbd_migration] Fix #42263, tool inserting ! on toString/hashCode

Fixed: 42263
Change-Id: Ia4c6d3543bc7628c76b85d986b9709de58925884
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/151441
Auto-Submit: Mike Fairhurst <mfairhurst@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Samuel Rawlins <srawlins@google.com>

Author: MichaelRFairhurst

pkg/nnbd_migration/lib/src/fix_builder.dart

@@ -293,9 +293,13 @@ class FixReason_NullCheckHint implements SimpleFixReasonInfo {
 
 /// Implementation of [MigrationResolutionHooks] that interfaces with
 /// [FixBuilder].
-class MigrationResolutionHooksImpl implements MigrationResolutionHooks {
+class MigrationResolutionHooksImpl
+    with ResolutionUtils
+    implements MigrationResolutionHooks {
   FixBuilder _fixBuilder;
 
+  TypeProvider get typeProvider => _fixBuilder.typeProvider;
+
   final Expando<List<CollectionElement>> _collectionElements = Expando();
 
   final Expando<bool> _shouldStayNullAware = Expando();
@@ -583,8 +587,18 @@ class MigrationResolutionHooksImpl implements MigrationResolutionHooks {
     return type;
   }
 
+  Element get _elementToString =>
+      _fixBuilder.typeProvider.objectType.getMethod('toString');
+  Element get _elementHashCode =>
+      _fixBuilder.typeProvider.objectType.getGetter('hashCode');
+  Element get _elementRuntimeType =>
+      _fixBuilder.typeProvider.objectType.getMethod('runtimeType');
+  Element get _elementNoSuchMethod =>
+      _fixBuilder.typeProvider.objectType.getGetter('noSuchMethod');
+
   bool _needsNullCheckDueToStructure(Expression node) {
     var parent = node.parent;
+
     if (parent is BinaryExpression) {
       if (identical(node, parent.leftOperand)) {
         var operatorType = parent.operator.type;
@@ -597,16 +611,22 @@ class MigrationResolutionHooksImpl implements MigrationResolutionHooks {
         }
       }
     } else if (parent is PrefixedIdentifier) {
-      // TODO(paulberry): ok for toString etc. if the shape is correct
+      if (isDeclaredOnObject(parent.identifier.name)) {
+        return false;
+      }
       return identical(node, parent.prefix);
     } else if (parent is PropertyAccess) {
+      if (isDeclaredOnObject(parent.propertyName.name)) {
+        return false;
+      }
       // TODO(paulberry): what about cascaded?
-      // TODO(paulberry): ok for toString etc. if the shape is correct
       return parent.operator.type == TokenType.PERIOD &&
           identical(node, parent.target);
     } else if (parent is MethodInvocation) {
+      if (isDeclaredOnObject(parent.methodName.name)) {
+        return false;
+      }
       // TODO(paulberry): what about cascaded?
-      // TODO(paulberry): ok for toString etc. if the shape is correct
       return parent.operator.type == TokenType.PERIOD &&
           identical(node, parent.target);
     } else if (parent is IndexExpression) {

pkg/nnbd_migration/test/fix_builder_test.dart

@@ -1905,7 +1905,6 @@ int _g() => 1;
     visitSubexpression(findNode.methodInvocation('_g();'), 'int');
   }
 
-  @FailingTest(reason: 'TODO(paulberry)')
   Future<void> test_methodInvocation_toString() async {
     await analyze('''
 abstract class _C {}
@@ -2379,7 +2378,6 @@ _f(_C c) => c.x;
     visitSubexpression(findNode.prefixed('c.x'), 'int?');
   }
 
-  @FailingTest(reason: 'TODO(paulberry)')
   Future<void> test_prefixedIdentifier_object_getter() async {
     await analyze('''
 class _C {}
@@ -2388,7 +2386,6 @@ _f(_C/*?*/ c) => c.hashCode;
     visitSubexpression(findNode.prefixed('c.hashCode'), 'int');
   }
 
-  @FailingTest(reason: 'TODO(paulberry)')
   Future<void> test_prefixedIdentifier_object_tearoff() async {
     await analyze('''
 class _C {}
@@ -2784,7 +2781,6 @@ _f(_C<int>/*?*/ c) => c?.x;
     visitSubexpression(findNode.propertyAccess('c?.x'), 'List<int>?');
   }
 
-  @FailingTest(reason: 'TODO(paulberry)')
   Future<void> test_propertyAccess_object_getter() async {
     await analyze('''
 class _C {}
@@ -2793,7 +2789,6 @@ _f(_C/*?*/ c) => (c).hashCode;
     visitSubexpression(findNode.propertyAccess('(c).hashCode'), 'int');
   }
 
-  @FailingTest(reason: 'TODO(paulberry)')
   Future<void> test_propertyAccess_object_tearoff() async {
     await analyze('''
 class _C {}