Add a path.formatUri method and release path 1.2.0.

pkg/path/test/windows_test.dart

Index: pkg/path/test/windows_test.dart
diff --git a/pkg/path/test/windows_test.dart b/pkg/path/test/windows_test.dart
index d19466356ad8465c187c283cd98d12034504da42..010cd351b30e75c605d7f0764801183367b42945 100644
--- a/pkg/path/test/windows_test.dart
+++ b/pkg/path/test/windows_test.dart
@@ -640,4 +640,33 @@ main() {
     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');
+    });
+  });
 }