Roll Observatory packages and add a roll script

packages/path/test/io_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.
+
+import 'dart:io' as io;
+
+import 'package:unittest/unittest.dart';
+import 'package:path/path.dart' as path;
+
+main() {
+  group('new Context()', () {
+    test('uses the current directory if root and style are omitted', () {
+      var context = new path.Context();
+      expect(context.current, io.Directory.current.path);
+    });
+
+    test('uses "." if root is omitted', () {
+      var context = new path.Context(style: path.Style.platform);
+      expect(context.current, ".");
+    });
+
+    test('uses the host platform if style is omitted', () {
+      var context = new path.Context();
+      expect(context.style, path.Style.platform);
+    });
+  });
+
+  test('Style.platform returns the host platform style', () {
+    if (io.Platform.operatingSystem == 'windows') {
+      expect(path.Style.platform, path.Style.windows);
+    } else {
+      expect(path.Style.platform, path.Style.posix);
+    }
+  });
+
+  test('current', () {
+    expect(path.current, io.Directory.current.path);
+  });
+
+  test('registers changes to the working directory', () {
+    var dir = io.Directory.current.path;
+    try {
+      expect(path.absolute('foo/bar'), equals(path.join(dir, 'foo/bar')));
+      expect(
+          path.absolute('foo/bar'), equals(path.context.join(dir, 'foo/bar')));
+
+      io.Directory.current = path.dirname(dir);
+      expect(path.normalize(path.absolute('foo/bar')),
+          equals(path.normalize(path.join(dir, '../foo/bar'))));
+      expect(path.normalize(path.absolute('foo/bar')),
+          equals(path.normalize(path.context.join(dir, '../foo/bar'))));
+    } finally {
+      io.Directory.current = dir;
+    }
+  });
+}