Add fixes for extends_non_class

Bug: Dart-Code/Dart-Code#2536
Change-Id: I5e4fa5a3625016045d86462b941cee3c73a36a04
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/150932
Commit-Queue: Danny Tuppeny <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: DanTup

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

@@ -482,6 +482,9 @@ class FixProcessor extends BaseProcessor {
     CompileTimeErrorCode.CONST_WITH_NON_TYPE: [
       ImportLibrary.forType,
     ],
+    CompileTimeErrorCode.EXTENDS_NON_CLASS: [
+      ImportLibrary.forType,
+    ],
     CompileTimeErrorCode.EXTRA_POSITIONAL_ARGUMENTS: [
       AddMissingParameter.newInstance,
     ],
@@ -579,6 +582,10 @@ class FixProcessor extends BaseProcessor {
     CompileTimeErrorCode.CONST_WITH_NON_TYPE: [
       ChangeTo.classOrMixin,
     ],
+    CompileTimeErrorCode.EXTENDS_NON_CLASS: [
+      ChangeTo.classOrMixin,
+      CreateClass.newInstance,
+    ],
     CompileTimeErrorCode.EXTENSION_OVERRIDE_ACCESS_TO_STATIC_MEMBER: [
       ReplaceWithExtensionName.newInstance,
     ],

pkg/analysis_server/test/edit/fixes_test.dart

@@ -31,6 +31,24 @@ class FixesTest extends AbstractAnalysisTest {
     handler = EditDomainHandler(server);
   }
 
+  Future<void> test_fixExtendsNonClass() async {
+    createProject();
+    addTestFile('''
+class MyCompleter extends Completer<String> {}
+
+class Completer2 {}
+''');
+    await waitForTasksFinished();
+    doAllDeclarationsTrackerWork();
+    var errorFixes = await _getFixesAt('extends Completer');
+    expect(errorFixes, hasLength(1));
+    var fixes = errorFixes[0].fixes;
+    expect(fixes, hasLength(3));
+    expect(fixes[0].message, matches('Import library'));
+    expect(fixes[1].message, matches("Change to 'Completer2'"));
+    expect(fixes[2].message, matches("Create class 'Completer'"));
+  }
+
   Future<void> test_fixUndefinedClass() async {
     createProject();
     addTestFile('''

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

@@ -54,6 +54,19 @@ void f() {}
 ''');
   }
 
+  Future<void> test_class_extends() async {
+    await resolveTestUnit('''
+class MyClass extends BaseClssa {}
+
+class BaseClass {}
+''');
+    await assertHasFix('''
+class MyClass extends BaseClass {}
+
+class BaseClass {}
+''');
+  }
+
   Future<void> test_class_fromImport() async {
     await resolveTestUnit('''
 main() {

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

@@ -38,6 +38,18 @@ class Test {
         change.linkedEditGroups[0], ["Test('", 'Test {', 'Test(S']);
   }
 
+  Future<void> test_extends() async {
+    await resolveTestUnit('''
+class MyClass extends BaseClass {}
+''');
+    await assertHasFix('''
+class MyClass extends BaseClass {}
+
+class BaseClass {
+}
+''');
+  }
+
   Future<void> test_hasUnresolvedPrefix() async {
     await resolveTestUnit('''
 main() {

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

@@ -47,6 +47,17 @@ main(p) {
 ''');
   }
 
+  Future<void> test_withClass_extends() async {
+    await resolveTestUnit('''
+class MyCompleter extends Completer<String> {}
+''');
+    await assertHasFix('''
+import 'dart:async';
+
+class MyCompleter extends Completer<String> {}
+''');
+  }
+
   Future<void> test_withClass_instanceCreation_explicitNew() async {
     await resolveTestUnit('''
 class C {