[DAS] Fixes "Add import" for Object? variables

Fixes: #60973
Change-Id: Ib31ca4141f1cf29806c38e9ba6bd4b1fdac1f846
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/442725
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Auto-Submit: Felipe Morschel <[email protected]>

Author: FMorschel

pkg/analysis_server/lib/src/services/correction/fix_internal.dart

@@ -1404,6 +1404,15 @@ final _builtInNonLintMultiGenerators = {
     CreateMixin.new,
     ImportLibrary.forType,
   ],
+  CompileTimeErrorCode.UNCHECKED_METHOD_INVOCATION_OF_NULLABLE_VALUE: [
+    ImportLibrary.forExtensionMember,
+  ],
+  CompileTimeErrorCode.UNCHECKED_OPERATOR_INVOCATION_OF_NULLABLE_VALUE: [
+    ImportLibrary.forExtensionMember,
+  ],
+  CompileTimeErrorCode.UNCHECKED_PROPERTY_ACCESS_OF_NULLABLE_VALUE: [
+    ImportLibrary.forExtensionMember,
+  ],
   CompileTimeErrorCode.UNDEFINED_ANNOTATION: [
     CreateClass.new,
     ImportLibrary.forTopLevelVariable,

pkg/analysis_server/test/src/services/correction/fix/import_library_project_test.dart

@@ -972,6 +972,66 @@ void f() { new Foo(); }
     );
   }
 
+  Future<void> test_unchecked_methodInvocation() async {
+    newFile('$testPackageLibPath/lib.dart', '''
+extension E on Object? {
+  void m() {}
+}
+''');
+    await resolveTestCode('''
+void f(Object? o) {
+  o.m();
+}
+''');
+    await assertHasFix('''
+import 'package:test/lib.dart';
+
+void f(Object? o) {
+  o.m();
+}
+''');
+  }
+
+  Future<void> test_unchecked_operatorInvocation() async {
+    newFile('$testPackageLibPath/lib.dart', '''
+extension E on Object? {
+  int operator +(int other) => 0;
+}
+''');
+    await resolveTestCode('''
+void f(Object? o) {
+  o + 1;
+}
+''');
+    await assertHasFix('''
+import 'package:test/lib.dart';
+
+void f(Object? o) {
+  o + 1;
+}
+''');
+  }
+
+  Future<void> test_unchecked_propertyAccess() async {
+    newFile('$testPackageLibPath/lib.dart', '''
+extension E on Object? {
+  int get getter => 0;
+}
+''');
+    await resolveTestCode('''
+void f(Object? o) {
+  o.getter;
+}
+''');
+    await assertHasFix('''
+import 'package:test/lib.dart';
+
+void f(Object? o) {
+  o.getter;
+}
+''');
+  }
+
   Future<void> test_withClass_annotation() async {
     newFile('$testPackageLibPath/lib.dart', '''
 class Test {