Missing @required arg quick fix improvements.

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.
 
 library test.services.correction.fix;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/edit/fix/fix_core.dart';
 import 'package:analysis_server/plugin/edit/fix/fix_dart.dart';
@@ skipping 459 matching lines @@
         '''
 import 'package:meta/meta.dart';
 
 test({@required int a, @required int bcd}) {}
 main() {
   test(a: 3, bcd: null);
 }
 ''');
   }
 
+  test_addMissingRequiredArg_multiple_2() async {
+    _addMetaPackageSource();
+
+    await resolveTestUnit('''
+import 'package:meta/meta.dart';
+
+test({@required int a, @required int bcd}) {}
+main() {
+  test();
+}
+''');
+
+    // For now we expect one error per missing arg (dartbug.com/28830).
+    List<AnalysisError> errors = await _computeErrors();
+    expect(errors, hasLength(2));
+
+    List<AnalysisError> filteredErrors = errors
+        .where((e) => e.message == "The parameter 'a' is required.")
+        .toList();
+    expect(filteredErrors, hasLength(1));
+
+    List<Fix> fixes = await _computeFixes(filteredErrors.first);
+
+    List<Fix> filteredFixes = fixes
+        .where((fix) => fix.change.message == "Add required argument 'a'")
+        .toList();
+    expect(filteredFixes, hasLength(1));
+    change = filteredFixes.first.change;
+    resultCode = SourceEdit.applySequence(testCode, change.edits[0].edits);
+    // verify
+    expect(
+        resultCode,
+        '''
+import 'package:meta/meta.dart';
+
+test({@required int a, @required int bcd}) {}
+main() {
+  test(a: null);
+}
+''');
+  }
+
   test_addMissingRequiredArg_single() async {
     _addMetaPackageSource();
 
     await resolveTestUnit('''
 import 'package:meta/meta.dart';
 
 test({@required int abc}) {}
 main() {
   test();
 }
@@ skipping 26 matching lines @@
         '''
 import 'package:meta/meta.dart';
 
 test(String x, {@required int abc}) {}
 main() {
   test("foo", abc: null);
 }
 ''');
   }
 
+  test_addMissingRequiredArg_single_with_details() async {
+    _addMetaPackageSource();
+
+    await resolveTestUnit('''
+import 'package:meta/meta.dart';
+
+test({@Required("Really who doesn't need an abc?") int abc}) {}
+main() {
+  test();
+}
+''');
+    await assertHasFix(
+        DartFixKind.ADD_MISSING_REQUIRED_ARGUMENT,
+        '''
+import 'package:meta/meta.dart';
+
+test({@Required("Really who doesn't need an abc?") int abc}) {}
+main() {
+  test(abc: null);
+}
+''');
+  }
+
   test_addSync_asyncFor() async {
     await resolveTestUnit('''
 import 'dart:async';
 void main(Stream<String> names) {
   await for (String name in names) {
     print(name);
   }
 }
 ''');
     await assertHasFix(
@@ skipping 4891 matching lines @@
         '''
 import 'dart:math' as pref;
 main() {
   print(pref.E);
   print(pref.PI);
 }
 ''');
   }
 
   void _addMetaPackageSource() {
-    addPackageSource('meta', 'meta.dart', r'''
+    addPackageSource(
+        'meta',
+        'meta.dart',
+        r'''
 library meta;
 
 const Required required = const Required();
 
 class Required {
   final String reason;
   const Required([this.reason]);
 }
 ''');
   }
@@ skipping 315 matching lines @@
 
   @override
   final CompilationUnit unit;
 
   @override
   final AnalysisError error;
 
   _DartFixContextImpl(this.resourceProvider, this.getTopLevelDeclarations,
       this.analysisContext, this.astProvider, this.unit, this.error);
 }