Fix for filtering unknown options.

pkg/analyzer/test/options_test.dart

 // Copyright (c) 2013, 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 options_test;
 
 import 'package:analyzer/options.dart';
+import 'package:args/args.dart';
 import 'package:unittest/unittest.dart';
-import 'package:args/args.dart';
+
+import 'reflective_tests.dart';
 
 main() {
 
   group('AnalyzerOptions.parse()', () {
 
     test('defaults', () {
       CommandLineOptions options =
           CommandLineOptions.parse(['--dart-sdk', '.', 'foo.dart']);
       expect(options, isNotNull);
       expect(options.dartSdkPath, isNotNull);
@@ skipping 119 matching lines @@
               '--baz',
               '--dart-sdk',
               '.',
               'foo.dart']);
       expect(options, isNotNull);
       expect(options.sourceFiles, equals(['foo.dart']));
     });
 
   });
 
+  runReflectiveTests(CommandLineParserTest);
 }
+
+
+@reflectiveTest
+class CommandLineParserTest {
+  test_ignoreUnrecognizedOptions() {
+    CommandLineParser parser =
+        new CommandLineParser(alwaysIgnoreUnrecognized: true);
+    parser.addOption('optionA');
+    parser.addFlag('flagA');
+    ArgResults argResults =
+        parser.parse(['--optionA=1', '--optionB=2', '--flagA'], {});
+    expect(argResults['optionA'], '1');
+    expect(argResults['flagA'], isTrue);
+  }
+}