move CommandLineParser into analyzer for reuse by DDC

pkg/analyzer/test/src/command_line/command_line_parser_test.dart

+// Copyright (c) 2016, 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 analyzer.test.src.command_line.command_line_parser_test;
+
+import 'package:analyzer/src/command_line/command_line_parser.dart';
+import 'package:args/args.dart';
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(CommandLineParserTest);
+  });
+}
+
+@reflectiveTest
+class CommandLineParserTest {
+  void test_usage() {
+    CommandLineParser parser = new CommandLineParser();
+    parser.addOption('bar');
+    String usage = parser.parser.usage;
+    expect(usage, contains('--bar'));
+    expect(usage, contains(CommandLineParser.IGNORE_UNRECOGNIZED_FLAG));
+  }
+
+  void test_unrecognizedFlags1() {
+    CommandLineParser parser = new CommandLineParser();
+    expect(() {
+      return parser.parse(['--bar', '--baz', 'foo.dart']);
+    }, throwsA(new isInstanceOf<FormatException>()));
+  }
+
+  void test_unrecognizedFlags2() {
+    CommandLineParser parser = new CommandLineParser();
+    parser.addFlag('bar');
+    expect(() {
+      return parser.parse(['--bar', '--baz', 'foo.dart']);
+    }, throwsA(new isInstanceOf<FormatException>()));
+  }
+
+  void test_unrecognizedFlags_ignore() {
+    CommandLineParser parser =
+        new CommandLineParser(alwaysIgnoreUnrecognized: true);
+    parser.addOption('optA');
+    parser.addOption('optB');
+    parser.addOption('optG');
+    parser.addFlag('flagA');
+    ArgResults argResults = parser.parse([
+      '--optA=1',
+      '--optB',
+      '2',
+      '--optC=3',
+      '--flagA',
+      '--optD',
+      '4',
+      '5',
+      '--optG=9',
+      '--optH=10'
+    ]);
+    expect(argResults['optA'], '1');
+    expect(argResults['optB'], '2');
+    expect(argResults['optG'], '9');
+    expect(argResults['flagA'], isTrue);
+    expect(() {
+      return argResults['optC'];
+    }, throwsA(new isInstanceOf<ArgumentError>()));
+    expect(() {
+      return argResults['optD'];
+    }, throwsA(new isInstanceOf<ArgumentError>()));
+    expect(argResults.rest, orderedEquals(<String>['4', '5']));
+  }
+}