Add command support to args.

pkg/args/test/args_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 args_test;
 
 import 'package:unittest/unittest.dart';
 import 'package:args/args.dart';
 
 main() {
@@ skipping 52 matching lines @@
   group('ArgParser.getDefault()', () {
     test('returns the default value for an option', () {
       var parser = new ArgParser();
       parser.addOption('mode', defaultsTo: 'debug');
       expect(parser.getDefault('mode'), 'debug');
     });
 
     test('throws if the option is unknown', () {
       var parser = new ArgParser();
       parser.addOption('mode', defaultsTo: 'debug');
-      expect(()=>parser.getDefault('undefined'),
-          throwsArgumentError);
+      throwsIllegalArg(() => parser.getDefault('undefined'));
     });
   });
 
+  group('ArgParser.commands', () {
+    test('returns an empty map if there are no commands', () {
+      var parser = new ArgParser();
+      expect(parser.commands, isEmpty);
+    });
+
+    test('returns the commands that were added', () {
+      var parser = new ArgParser();
+      parser.addCommand('hide');
+      parser.addCommand('seek');
+      expect(parser.commands, hasLength(2));
+      expect(parser.commands['hide'], isNotNull);
+      expect(parser.commands['seek'], isNotNull);
+    });
+
+    test('iterates over the commands in the order they were added', () {
+      var parser = new ArgParser();
+      parser.addCommand('a');
+      parser.addCommand('d');
+      parser.addCommand('b');
+      parser.addCommand('c');
+      expect(parser.commands.keys, equals(['a', 'd', 'b', 'c']));
+    });
+  });
+
+  group('ArgParser.options', () {
+    test('returns an empty map if there are no options', () {
+      var parser = new ArgParser();
+      expect(parser.options, isEmpty);
+    });
+
+    test('returns the options that were added', () {
+      var parser = new ArgParser();
+      parser.addFlag('hide');
+      parser.addOption('seek');
+      expect(parser.options, hasLength(2));
+      expect(parser.options['hide'], isNotNull);
+      expect(parser.options['seek'], isNotNull);
+    });
+
+    test('iterates over the options in the order they were added', () {
+      var parser = new ArgParser();
+      parser.addFlag('a');
+      parser.addOption('d');
+      parser.addFlag('b');
+      parser.addOption('c');
+      expect(parser.options.keys, equals(['a', 'd', 'b', 'c']));
+    });
+  });
+
   group('ArgResults.options', () {
     test('returns the provided options', () {
       var parser = new ArgParser();
       parser.addFlag('woof');
       parser.addOption('meow');
       var args = parser.parse(['--woof', '--meow', 'kitty']);
       expect(args.options, hasLength(2));
       expect(args.options.any((o) => o == 'woof'), isTrue);
       expect(args.options.any((o) => o == 'meow'), isTrue);
     });
@@ skipping 18 matching lines @@
   });
 }
 
 throwsIllegalArg(function) {
   expect(function, throwsArgumentError);
 }
 
 throwsFormat(ArgParser parser, List<String> args) {
   expect(() => parser.parse(args), throwsFormatException);
 }