a === b -> identical(a, b)

tests/compiler/dart2js/uri_extras_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 'dart:uri';
 
 import '../../../sdk/lib/_internal/compiler/implementation/util/uri_extras.dart';
 
 
 void testRelativize() {
   void c(String expected, String base, String path, bool isWindows) {
-    if (isWindows === null) {
+    if (isWindows == null) {
       c(expected, base, path, true);
       c(expected, base, path, false);
       return;
     }
     String r;
 
     r = relativize(new Uri.fromString('file:$base'),
                    new Uri.fromString('file:$path'),
                    isWindows);
     Expect.stringEquals(expected, r);
@@ skipping 38 matching lines @@
 
   c('../person/file.dart', '/Users/other/', '/Users/person/file.dart', false);
 
   c('/Users/person/file.dart', '/Users/other/', '/Users/person/file.dart',
     true);
 }
 
 void main() {
   testRelativize();
 }