Add isWithin to pkg/path.

pkg/path/test/url_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.
 
 import 'package:unittest/unittest.dart';
 import 'package:path/path.dart' as path;
 
 main() {
   var builder = new path.Builder(style: path.Style.url,
       root: 'http://dartlang.org/root/path');
@@ skipping 597 matching lines @@
     test('from a . root', () {
       var r = new path.Builder(style: path.Style.url, root: '.');
       expect(r.relative('http://dartlang.org/foo/bar/baz'),
           equals('http://dartlang.org/foo/bar/baz'));
       expect(r.relative('file:///foo/bar/baz'), equals('file:///foo/bar/baz'));
       expect(r.relative('/foo/bar/baz'), equals('/foo/bar/baz'));
       expect(r.relative('foo/bar/baz'), equals('foo/bar/baz'));
     });
   });
 
+  group('isWithin', () {
+    test('simple cases', () {
+      expect(builder.isWithin('foo/bar', 'foo/bar'), isFalse);
+      expect(builder.isWithin('foo/bar', 'foo/bar/baz'), isTrue);
+      expect(builder.isWithin('foo/bar', 'foo/baz'), isFalse);
+      expect(builder.isWithin('foo/bar', '../path/foo/bar/baz'), isTrue);
+      expect(builder.isWithin(
+              'http://dartlang.org', 'http://dartlang.org/foo/bar'),
+          isTrue);
+      expect(builder.isWithin(
+              'http://dartlang.org', 'http://pub.dartlang.org/foo/bar'),
+          isFalse);
+      expect(builder.isWithin('http://dartlang.org', '/foo/bar'), isTrue);
+      expect(builder.isWithin('http://dartlang.org/foo', '/foo/bar'), isTrue);
+      expect(builder.isWithin('http://dartlang.org/foo', '/bar/baz'), isFalse);
+      expect(builder.isWithin('baz', 'http://dartlang.org/root/path/baz/bang'),
+          isTrue);
+      expect(builder.isWithin('baz', 'http://dartlang.org/root/path/bang/baz'),
+          isFalse);
+    });
+
+    test('from a relative root', () {
+      var r = new path.Builder(style: path.Style.url, root: 'foo/bar');
+      expect(builder.isWithin('.', 'a/b/c'), isTrue);
+      expect(builder.isWithin('.', '../a/b/c'), isFalse);
+      expect(builder.isWithin('.', '../../a/foo/b/c'), isFalse);
+      expect(builder.isWithin(
+              'http://dartlang.org/', 'http://dartlang.org/baz/bang'),
+          isTrue);
+      expect(builder.isWithin('.', 'http://dartlang.org/baz/bang'), isFalse);
+    });
+  });
+
   group('resolve', () {
     test('allows up to seven parts', () {
       expect(builder.resolve('a'), 'http://dartlang.org/root/path/a');
       expect(builder.resolve('a', 'b'), 'http://dartlang.org/root/path/a/b');
       expect(builder.resolve('a', 'b', 'c'),
           'http://dartlang.org/root/path/a/b/c');
       expect(builder.resolve('a', 'b', 'c', 'd'),
           'http://dartlang.org/root/path/a/b/c/d');
       expect(builder.resolve('a', 'b', 'c', 'd', 'e'),
           'http://dartlang.org/root/path/a/b/c/d/e');
@@ skipping 66 matching lines @@
     expect(builder.toUri('http://dartlang.org/path/to/foo%23bar'),
         Uri.parse('http://dartlang.org/path/to/foo%23bar'));
     // Since the input path is also a URI, special characters should already
     // be percent encoded there too.
     expect(builder.toUri(r'http://foo.com/_%7B_%7D_%60_%5E_%20_%22_%25_'),
         Uri.parse('http://foo.com/_%7B_%7D_%60_%5E_%20_%22_%25_'));
     expect(builder.toUri(r'_%7B_%7D_%60_%5E_%20_%22_%25_'),
         Uri.parse('_%7B_%7D_%60_%5E_%20_%22_%25_'));
   });
 }