Improve the performance of isWithin().

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:test/test.dart';
 import 'package:path/path.dart' as path;
 
 import 'utils.dart';
@@ skipping 519 matching lines @@
       expect(context.isWithin(r'foo\bar', r'..\path\foo\bar\baz'), isTrue);
       expect(context.isWithin(r'C:\', r'C:\foo\bar'), isTrue);
       expect(context.isWithin(r'C:\', r'D:\foo\bar'), isFalse);
       expect(context.isWithin(r'C:\', r'\foo\bar'), isTrue);
       expect(context.isWithin(r'C:\foo', r'\foo\bar'), isTrue);
       expect(context.isWithin(r'C:\foo', r'\bar\baz'), isFalse);
       expect(context.isWithin(r'baz', r'C:\root\path\baz\bang'), isTrue);
       expect(context.isWithin(r'baz', r'C:\root\path\bang\baz'), isFalse);
     });
 
+    test('complex cases', () {
+      expect(context.isWithin(r'foo\.\bar', r'foo\bar\baz'), isTrue);
+      expect(context.isWithin(r'foo\\bar', r'foo\bar\baz'), isTrue);
+      expect(context.isWithin(r'foo\qux\..\bar', r'foo\bar\baz'), isTrue);
+      expect(context.isWithin(r'foo\bar', r'foo\bar\baz\..\..'), isFalse);
+      expect(context.isWithin(r'foo\bar', r'foo\bar\\\'), isFalse);
+      expect(context.isWithin(r'foo\.bar', r'foo\.bar\baz'), isTrue);
+      expect(context.isWithin(r'foo\.\bar', r'foo\.bar\baz'), isFalse);
+      expect(context.isWithin(r'foo\..bar', r'foo\..bar\baz'), isTrue);
+      expect(context.isWithin(r'C:\', 'C:/foo'), isTrue);
+      expect(context.isWithin(r'C:\', r'D:\foo'), isFalse);
+      expect(context.isWithin(r'C:\', r'\\foo\bar'), isFalse);
+    });
+
+    test('with root-relative paths', () {
+      expect(context.isWithin(r'\foo', r'C:\foo\bar'), isTrue);
+      expect(context.isWithin(r'C:\foo', r'\foo\bar'), isTrue);
+      expect(context.isWithin(r'\root', r'foo\bar'), isTrue);
+      expect(context.isWithin(r'foo', r'\root\path\foo\bar'), isTrue);
+      expect(context.isWithin(r'\foo', r'\foo\bar'), isTrue);
+    });
+
     test('from a relative root', () {
       var r = new path.Context(style: path.Style.windows, current: r'foo\bar');
       expect(r.isWithin('.', r'a\b\c'), isTrue);
       expect(r.isWithin('.', r'..\a\b\c'), isFalse);
       expect(r.isWithin('.', r'..\..\a\foo\b\c'), isFalse);
       expect(r.isWithin(r'C:\', r'C:\baz\bang'), isTrue);
       expect(r.isWithin('.', r'C:\baz\bang'), isFalse);
     });
   });
 
@@ skipping 117 matching lines @@
 
     test('with a root-relative URI', () {
       expect(context.prettyUri('/D:/a/b'), r'D:\a\b');
     });
 
     test('with a Uri object', () {
       expect(context.prettyUri(Uri.parse('a/b')), r'a\b');
     });
   });
 }