Add a path.formatUri method and release path 1.2.0.

pkg/path/test/windows_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 path.test.windows_test;
 
 import 'package:unittest/unittest.dart';
 import 'package:path/path.dart' as path;
 
 import 'utils.dart';
@@ skipping 622 matching lines @@
     expect(context.toUri(r'foo\bar'), Uri.parse('foo/bar'));
     expect(context.toUri(r'C:\path\to\foo#bar'),
         Uri.parse('file:///C:/path/to/foo%23bar'));
     expect(context.toUri(r'\\server\share\path\to\foo#bar'),
         Uri.parse('file://server/share/path/to/foo%23bar'));
     expect(context.toUri(r'C:\_{_}_`_^_ _"_%_'),
         Uri.parse('file:///C:/_%7B_%7D_%60_%5E_%20_%22_%25_'));
     expect(context.toUri(r'_{_}_`_^_ _"_%_'),
         Uri.parse('_%7B_%7D_%60_%5E_%20_%22_%25_'));
   });
+
+  group('formatUri', () {
+    test('with a file: URI', () {
+      expect(context.formatUri(Uri.parse('file:///C:/root/path/a/b')), r'a\b');
+      expect(context.formatUri(Uri.parse('file:///C:/other/path/a/b')),
+          r'C:\other\path\a\b');
+      expect(context.formatUri(Uri.parse('file:///D:/root/path/a/b')),
+          r'D:\root\path\a\b');
+      expect(context.formatUri(Uri.parse('file:///C:/root/other')),
+          r'..\other');
+    });
+
+    test('with an http: URI', () {
+      expect(context.formatUri(Uri.parse('http://dartlang.org/a/b')),
+          'http://dartlang.org/a/b');
+    });
+
+    test('with a relative URI', () {
+      expect(context.formatUri(Uri.parse('a/b')), r'a\b');
+    });
+
+    test('with a root-relative URI', () {
+      expect(context.formatUri(Uri.parse('/D:/a/b')), r'D:\a\b');
+    });
+
+    test('with a String', () {
+      expect(context.formatUri('a/b'), r'a\b');
+    });
+  });
 }