Add toUri and fromUri functions to pathos.

pkg/pathos/test/pathos_posix_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 pathos_posix_test;
 
 import 'package:unittest/unittest.dart';
 import 'package:pathos/path.dart' as path;
 
 main() {
@@ skipping 381 matching lines @@
     expect(builder.withoutExtension('a/b/'), 'a/b/');
     expect(builder.withoutExtension('a/.'), 'a/.');
     expect(builder.withoutExtension('a/.b'), 'a/.b');
     expect(builder.withoutExtension('a.b/c'), 'a.b/c');
     expect(builder.withoutExtension(r'a.b\c'), r'a');
     expect(builder.withoutExtension(r'a/b\c'), r'a/b\c');
     expect(builder.withoutExtension(r'a/b\c.d'), r'a/b\c');
     expect(builder.withoutExtension('a/b.c/'), 'a/b/');
     expect(builder.withoutExtension('a/b.c//'), 'a/b//');
   });
+
+  test('fromUri', () {
+    expect(builder.fromUri(Uri.parse('file:///path/to/foo')), '/path/to/foo');
+    expect(builder.fromUri(Uri.parse('file:///path/to/foo/')), '/path/to/foo/');
+    expect(builder.fromUri(Uri.parse('file:///')), '/');
+    expect(builder.fromUri(Uri.parse('foo/bar')), 'foo/bar');
+    expect(builder.fromUri(Uri.parse('/path/to/foo')), '/path/to/foo');
+    expect(builder.fromUri(Uri.parse('///path/to/foo')), '/path/to/foo');
+    expect(builder.fromUri(Uri.parse('file:///path/to/foo%23bar')),
+        '/path/to/foo#bar');
+    expect(() => builder.fromUri(Uri.parse('http://dartlang.org')),
+        throwsArgumentError);
+  });
+
+  test('toUri', () {
+    expect(builder.toUri('/path/to/foo'), Uri.parse('file:///path/to/foo'));
+    expect(builder.toUri('/path/to/foo/'), Uri.parse('file:///path/to/foo/'));
+    expect(builder.toUri('/'), Uri.parse('file:///'));
+    expect(builder.toUri('foo/bar'), Uri.parse('foo/bar'));
+    expect(builder.toUri('/path/to/foo#bar'),
+        Uri.parse('file:///path/to/foo%23bar'));
+  });
 }