Add command support to args.

pkg/args/test/command_test.dart

Index: pkg/args/test/command_test.dart
diff --git a/pkg/args/test/command_test.dart b/pkg/args/test/command_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..50794256f1caf8b9adb777bea5b144737f77a1e6
--- /dev/null
+++ b/pkg/args/test/command_test.dart
@@ -0,0 +1,199 @@
+// 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 command_test;
+
+import 'package:unittest/unittest.dart';
+import 'package:args/args.dart';
+
+main() {
+  group('ArgParser.addCommand()', () {
+    test('throws on a duplicate command name', () {
+      var parser = new ArgParser();
+      parser.addCommand('install');
+      throwsIllegalArg(() => parser.addCommand('install'));
+    });
+  });
+
+  group('ArgParser.parse()', () {
+    test('parses a command', () {
+      var parser = new ArgParser();
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['install']);
+
+      expect(args.command.name, equals('install'));
+      expect(args.rest, isEmpty);
+    });
+
+    test('parses a command option', () {
+      var parser = new ArgParser();
+      var command = parser.addCommand('install');
+      command.addOption('path');
+
+      var args = parser.parse(['install', '--path', 'some/path']);
+      expect(args.command['path'], equals('some/path'));
+    });
+
+    test('parses a parent solo option before the command', () {
+      var parser = new ArgParser();
+      parser.addOption('mode', abbr: 'm');
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['-m', 'debug', 'install']);
+      expect(args['mode'], equals('debug'));
+      expect(args.command.name, equals('install'));
+    });
+
+    test('parses a parent solo option after the command', () {
+      var parser = new ArgParser();
+      parser.addOption('mode', abbr: 'm');
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['install', '-m', 'debug']);
+      expect(args['mode'], equals('debug'));
+      expect(args.command.name, equals('install'));
+    });
+
+    test('parses a parent option before the command', () {
+      var parser = new ArgParser();
+      parser.addFlag('verbose');
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['--verbose', 'install']);
+      expect(args['verbose'], isTrue);
+      expect(args.command.name, equals('install'));
+    });
+
+    test('parses a parent option after the command', () {
+      var parser = new ArgParser();
+      parser.addFlag('verbose');
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['install', '--verbose']);
+      expect(args['verbose'], isTrue);
+      expect(args.command.name, equals('install'));
+    });
+
+    test('parses a parent negated option before the command', () {
+      var parser = new ArgParser();
+      parser.addFlag('verbose', defaultsTo: true);
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['--no-verbose', 'install']);
+      expect(args['verbose'], isFalse);
+      expect(args.command.name, equals('install'));
+    });
+
+    test('parses a parent negated option after the command', () {
+      var parser = new ArgParser();
+      parser.addFlag('verbose', defaultsTo: true);
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['install', '--no-verbose']);
+      expect(args['verbose'], isFalse);
+      expect(args.command.name, equals('install'));
+    });
+
+    test('parses a parent abbreviation before the command', () {
+      var parser = new ArgParser();
+      parser.addFlag('debug', abbr: 'd');
+      parser.addFlag('verbose', abbr: 'v');
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['-dv', 'install']);
+      expect(args['debug'], isTrue);
+      expect(args['verbose'], isTrue);
+      expect(args.command.name, equals('install'));
+    });
+
+    test('parses a parent abbreviation after the command', () {
+      var parser = new ArgParser();
+      parser.addFlag('debug', abbr: 'd');
+      parser.addFlag('verbose', abbr: 'v');
+      var command = parser.addCommand('install');
+
+      var args = parser.parse(['install', '-dv']);
+      expect(args['debug'], isTrue);
+      expect(args['verbose'], isTrue);
+      expect(args.command.name, equals('install'));
+    });
+
+    test('does not parse a solo command option before the command', () {
+      var parser = new ArgParser();
+      var command = parser.addCommand('install');
+      command.addOption('path', abbr: 'p');
+
+      throwsFormat(parser, ['-p', 'foo', 'install']);
+    });
+
+    test('does not parse a command option before the command', () {
+      var parser = new ArgParser();
+      var command = parser.addCommand('install');
+      command.addOption('path');
+
+      throwsFormat(parser, ['--path', 'foo', 'install']);
+    });
+
+    test('does not parse a command abbreviation before the command', () {
+      var parser = new ArgParser();
+      var command = parser.addCommand('install');
+      command.addFlag('debug', abbr: 'd');
+      command.addFlag('verbose', abbr: 'v');
+
+      throwsFormat(parser, ['-dv', 'install']);
+    });
+
+    test('assigns collapsed options to the proper command', () {
+      var parser = new ArgParser();
+      parser.addFlag('apple', abbr: 'a');
+      var command = parser.addCommand('cmd');
+      command.addFlag('banana', abbr: 'b');
+      var subcommand = command.addCommand('subcmd');
+      subcommand.addFlag('cherry', abbr: 'c');
+
+      var args = parser.parse(['cmd', 'subcmd', '-abc']);
+      expect(args['apple'], isTrue);
+      expect(args.command.name, equals('cmd'));
+      expect(args.command['banana'], isTrue);
+      expect(args.command.command.name, equals('subcmd'));
+      expect(args.command.command['cherry'], isTrue);
+    });
+
+    test('option is given to innermost command that can take it', () {
+      var parser = new ArgParser();
+      parser.addFlag('verbose');
+      var command = parser.addCommand('cmd');
+      command.addFlag('verbose');
+      var subcommand = command.addCommand('subcmd');
+
+      var args = parser.parse(['cmd', 'subcmd', '--verbose']);
+      expect(args['verbose'], isFalse);
+      expect(args.command.name, equals('cmd'));
+      expect(args.command['verbose'], isTrue);
+      expect(args.command.command.name, equals('subcmd'));
+    });
+
+    test('remaining arguments are given to the innermost command', () {
+      var parser = new ArgParser();
+      var command = parser.addCommand('cmd');
+      var subcommand = command.addCommand('subcmd');
+
+      var args = parser.parse(['cmd', 'subcmd', 'other', 'stuff']);
+      expect(args.command.name, equals('cmd'));
+      expect(args.rest, isEmpty);
+      expect(args.command.command.name, equals('subcmd'));
+      expect(args.command.rest, isEmpty);
+      expect(args.command.command.rest, equals(['other', 'stuff']));
+    });
+  });
+}
+
+throwsIllegalArg(function) {
+  expect(function, throwsArgumentError);
+}
+
+throwsFormat(ArgParser parser, List<String> args) {
+  expect(() => parser.parse(args), throwsFormatException);
+}