Quick fix to ignore a specific error (#25915).

pkg/analysis_server/test/edit/fixes_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.edit.fixes;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analysis_server/src/edit/edit_domain.dart';
+import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:plugin/manager.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart' hide ERROR;
 
 import '../analysis_abstract.dart';
 import '../mocks.dart';
 import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
   defineReflectiveTests(FixesTest);
 }
 
 @reflectiveTest
 class FixesTest extends AbstractAnalysisTest {
   @override
   void setUp() {
     super.setUp();
     createProject();
     ExtensionManager manager = new ExtensionManager();
     manager.processPlugins([server.serverPlugin]);
     handler = new EditDomainHandler(server);
   }
 
   test_fixUndefinedClass() async {
     addTestFile('''
 main() {
   Future<String> x = null;
+  print(x);

[scheglov, 2016/03/04 18:55:20]

Why do we need this statement?

[pquitslund, 2016/03/04 19:09:39]

Without it, we get an `unused_local_variable` hint w/ an associated fix which
means errorFixes contains two fixes breaking the expect at line 46.  Seemed
easier to just not see this hint at all.

 }
 ''');
     await waitForTasksFinished();
     List<AnalysisErrorFixes> errorFixes = await _getFixesAt('Future<String>');
     expect(errorFixes, hasLength(1));
     AnalysisError error = errorFixes[0].error;
     expect(error.severity, AnalysisErrorSeverity.WARNING);
     expect(error.type, AnalysisErrorType.STATIC_WARNING);
     List<SourceChange> fixes = errorFixes[0].fixes;
-    expect(fixes, hasLength(2));
+    expect(fixes, hasLength(3));
     expect(fixes[0].message, matches('Import library'));
     expect(fixes[1].message, matches('Create class'));
+    expect(
+        fixes[2].message, matches("Ignore error with code 'undefined_class'"));
   }
 
   test_hasFixes() async {
     addTestFile('''
 foo() {
   print(1)
 }
 bar() {
   print(10) print(20)
 }
@@ skipping 47 matching lines @@
     return await _getFixes(offset);
   }
 
   void _isSyntacticErrorWithSingleFix(AnalysisErrorFixes fixes) {
     AnalysisError error = fixes.error;
     expect(error.severity, AnalysisErrorSeverity.ERROR);
     expect(error.type, AnalysisErrorType.SYNTACTIC_ERROR);
     expect(fixes.fixes, hasLength(1));
   }
 }