Follow getopt in parsing option-like values.

test/parse_test.dart

 // Copyright (c) 2012, 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 parse_test;
 
 import 'package:test/test.dart';
 import 'package:args/args.dart';
 import 'utils.dart';
 
@@ skipping 297 matching lines @@
         throwsFormat(parser, ['-f']);
       });
 
       test('throw if the value is missing', () {
         var parser = new ArgParser();
         parser.addOption('file', abbr: 'f');
 
         throwsFormat(parser, ['-f']);
       });
 
-      test('throw if the value looks like an option', () {
+      test('does not throw if the value looks like an option', () {
         var parser = new ArgParser();
         parser.addOption('file', abbr: 'f');
         parser.addOption('other');
 
-        throwsFormat(parser, ['-f', '--other']);
-        throwsFormat(parser, ['-f', '--unknown']);
-        throwsFormat(parser, ['-f', '-abbr']);
+        expect(parser.parse(['-f', '--other'])['file'], equals('--other'));
+        expect(parser.parse(['-f', '--unknown'])['file'], equals('--unknown'));
+        expect(parser.parse(['-f', '-abbr'])['file'], equals('-abbr'));
+        expect(parser.parse(['-f', '--'])['file'], equals('--'));
       });
 
       test('throw if the value is not allowed', () {
         var parser = new ArgParser();
         parser.addOption('mode', abbr: 'm', allowed: ['debug', 'release']);
 
         throwsFormat(parser, ['-mprofile']);
       });
 
       test('throw if a comma-separated value is not allowed', () {
@@ skipping 66 matching lines @@
         throwsFormat(parser, ['--unknown']);
         throwsFormat(parser, ['--nobody']); // Starts with "no".
       });
 
       test('throw if the arg does not include a value', () {
         var parser = new ArgParser();
         parser.addOption('mode');
         throwsFormat(parser, ['--mode']);
       });
 
-      test('throw if the value looks like an option', () {
+      test('do not throw if the value looks like an option', () {
         var parser = new ArgParser();
         parser.addOption('mode');
         parser.addOption('other');
 
-        throwsFormat(parser, ['--mode', '--other']);
-        throwsFormat(parser, ['--mode', '--unknown']);
-        throwsFormat(parser, ['--mode', '-abbr']);
+        expect(parser.parse(['--mode', '--other'])['mode'], equals('--other'));
+        expect(parser.parse(['--mode', '--unknown'])['mode'],
+            equals('--unknown'));
+        expect(parser.parse(['--mode', '-abbr'])['mode'], equals('-abbr'));
+        expect(parser.parse(['--mode', '--'])['mode'], equals('--'));
       });
 
       test('do not throw if the value is in the allowed set', () {
         var parser = new ArgParser();
         parser.addOption('mode', allowed: ['debug', 'release']);
         var args = parser.parse(['--mode=debug']);
         expect(args['mode'], equals('debug'));
       });
 
       test('throw if the value is not in the allowed set', () {
@@ skipping 65 matching lines @@
         var parser = new ArgParser();
         parser.addFlag('woof');
 
         var results = parser.parse(['--woof', 'stop', '--', 'arg']);
         expect(results['woof'], isTrue);
         expect(results.rest, equals(['stop', '--', 'arg']));
       });
     });
   });
 }