Add default implementation when fixing missing required closures (flutter-intellij#975)

pkg/analysis_server/test/services/correction/fix_test.dart

 // Copyright (c) 2014, 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.
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/edit/fix/fix_core.dart';
 import 'package:analysis_server/plugin/edit/fix/fix_dart.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart'
     hide AnalysisError;
@@ skipping 448 matching lines @@
         '''
 import 'libA.dart';
 
 main() {
   A a = new A(a: null);
 }
 ''',
         target: '/test.dart');
   }
 
+  test_addMissingRequiredArg_cons_single_closure() async {
+    _addMetaPackageSource();
+
+    addSource(
+        '/libA.dart',
+        r'''
+library libA;
+import 'package:meta/meta.dart';
+
+typedef void VoidCallback();
+
+class A {
+  A({@required VoidCallback onPressed}) {}
+}
+''');
+
+    await resolveTestUnit('''
+import 'libA.dart';
+
+main() {
+  A a = new A();
+}
+''');
+    await assertHasFix(
+        DartFixKind.ADD_MISSING_REQUIRED_ARGUMENT,
+        '''
+import 'libA.dart';
+
+main() {
+  A a = new A(onPressed: () {});
+}
+''',
+        target: '/test.dart');
+  }
+
+  test_addMissingRequiredArg_cons_single_closure_2() async {
+    _addMetaPackageSource();
+
+    addSource(
+        '/libA.dart',
+        r'''
+library libA;
+import 'package:meta/meta.dart';
+
+typedef void Callback(e);
+
+class A {
+  A({@required Callback callback}) {}
+}
+''');
+
+    await resolveTestUnit('''
+import 'libA.dart';
+
+main() {
+  A a = new A();
+}
+''');
+    await assertHasFix(
+        DartFixKind.ADD_MISSING_REQUIRED_ARGUMENT,
+        '''
+import 'libA.dart';
+
+main() {
+  A a = new A(callback: (e) {});
+}
+''',
+        target: '/test.dart');
+  }
+
+  test_addMissingRequiredArg_cons_single_closure_3() async {
+    _addMetaPackageSource();
+
+    addSource(
+        '/libA.dart',
+        r'''
+library libA;
+import 'package:meta/meta.dart';
+
+typedef void Callback(a,b,c);
+
+class A {
+  A({@required Callback callback}) {}
+}
+''');
+
+    await resolveTestUnit('''
+import 'libA.dart';
+
+main() {
+  A a = new A();
+}
+''');
+    await assertHasFix(
+        DartFixKind.ADD_MISSING_REQUIRED_ARGUMENT,
+        '''
+import 'libA.dart';
+
+main() {
+  A a = new A(callback: (a, b, c) {});
+}
+''',
+        target: '/test.dart');
+  }
+
+  test_addMissingRequiredArg_cons_single_closure_4() async {
+    _addMetaPackageSource();
+
+    addSource(
+        '/libA.dart',
+        r'''
+library libA;
+import 'package:meta/meta.dart';
+
+typedef int Callback(a,b,c);
+
+class A {
+  A({@required Callback callback}) {}
+}
+''');
+
+    await resolveTestUnit('''
+import 'libA.dart';
+
+main() {
+  A a = new A();
+}
+''');
+    await assertHasFix(
+        DartFixKind.ADD_MISSING_REQUIRED_ARGUMENT,
+        '''
+import 'libA.dart';
+
+main() {
+  A a = new A(callback: (a, b, c) {});
+}
+''',
+        target: '/test.dart');
+  }
+
+  test_addMissingRequiredArg_cons_single_list() async {
+    _addMetaPackageSource();
+
+    addSource(
+        '/libA.dart',
+        r'''
+library libA;
+import 'package:meta/meta.dart';
+
+class A {
+  A({@required List<String> names}) {}
+}
+''');
+
+    await resolveTestUnit('''
+import 'libA.dart';
+
+main() {
+  A a = new A();
+}
+''');
+    await assertHasFix(
+        DartFixKind.ADD_MISSING_REQUIRED_ARGUMENT,
+        '''
+import 'libA.dart';
+
+main() {
+  A a = new A(names: <String>[]);
+}
+''',
+        target: '/test.dart');
+  }
+
   test_addMissingRequiredArg_multiple() async {
     _addMetaPackageSource();
 
     await resolveTestUnit('''
 import 'package:meta/meta.dart';
 
 test({@required int a, @required int bcd}) {}
 main() {
   test(a: 3);
 }
@@ skipping 6237 matching lines @@
 
   @override
   final CompilationUnit unit;
 
   @override
   final AnalysisError error;
 
   _DartFixContextImpl(this.resourceProvider, this.getTopLevelDeclarations,
       this.analysisContext, this.astProvider, this.unit, this.error);
 }