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

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

Index: pkg/analysis_server/test/services/correction/fix_test.dart
diff --git a/pkg/analysis_server/test/services/correction/fix_test.dart b/pkg/analysis_server/test/services/correction/fix_test.dart
index f128f88fc1462b86c22ad632f9bbe9d25551e547..53b0d4a27b3441ad6ec587a641a4c74fe014488d 100644
--- a/pkg/analysis_server/test/services/correction/fix_test.dart
+++ b/pkg/analysis_server/test/services/correction/fix_test.dart
@@ -466,6 +466,179 @@ main() {
         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();