Add normalizePath to Uri class.

tests/corelib/uri_normalize_path_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 uriNormalizePathTest;
+
+import "package:expect/expect.dart";
+
+test(String path, String normalizedPath) {
+  for (var scheme in ["http", "file", "unknown"]) {
+    for (var auth in [[null, "hostname", null],
+                      ["userinfo", "hostname", 1234],
+                      [null, null, null]]) {
+      for (var query in [null, "query"]) {
+        for (var fragment in [null, "fragment"]) {
+          var base = new Uri(scheme: scheme,
+                             userInfo: auth[0],
+                             host: auth[1],
+                             port: auth[2],
+                             path: path,
+                             query: query,
+                             fragment: fragment);
+          var expected = base.replace(path:
+              (base.hasAuthority && normalizedPath.isEmpty) ? "/"
+                                                            : normalizedPath);
+          var actual = base.normalizePath();
+          Expect.equals(expected, actual, "$base");
+        }
+      }
+    }
+  }
+}
+testNoChange(String path) {
+  test(path, path);
+}
+
+main() {
+  testNoChange("foo/bar/baz");
+  testNoChange("/foo/bar/baz");
+  testNoChange("foo/bar/baz/");
+  test("foo/bar/..", "foo/");
+  test("foo/bar/.", "foo/bar/");
+  test("foo/./bar/../baz", "foo/baz");
+  test("../../foo", "foo");
+  test("./../foo", "foo");
+  test("./../", "");
+  test("./../.", "");
+  test("foo/bar/baz/../../../../qux", "qux");
+  test("/foo/bar/baz/../../../../qux", "/qux");
+  test(".", "");
+  test("..", "");
+  test("/.", "/");
+  test("/..", "/");
+}