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

runtime/tests/vm/dart/isolate_mirror_local_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.
 //
 // Dart test program for checking implemention of MirrorSystem when
 // inspecting the current isolate.
 //
 // VMOptions=--enable_type_checks
 
 library isolate_mirror_local_test;
@@ skipping 299 matching lines @@
   Expect.equals('Collection', list_intf.superinterfaces[0].simpleName);
   Expect.equals("ClassMirror on 'List'", list_intf.toString());
 
   // Lookup a class from a library and make sure it is sane.
   ClassMirror oom_cls = core_lib.members['OutOfMemoryError'];
   Expect.isTrue(oom_cls is ClassMirror);
   Expect.equals('OutOfMemoryError', oom_cls.simpleName);
   Expect.equals('dart:core.OutOfMemoryError', oom_cls.qualifiedName);
   Expect.isFalse(oom_cls.isPrivate);
   Expect.equals('Object', oom_cls.superclass.simpleName);
-  Expect.isTrue(oom_cls.defaultFactory === null);
+  Expect.isTrue(oom_cls.defaultFactory == null);
   Expect.equals('dart:core', oom_cls.owner.simpleName);
   Expect.isTrue(oom_cls.isClass);
   Expect.equals('Error', oom_cls.superinterfaces[0].simpleName);
   Expect.equals("ClassMirror on 'OutOfMemoryError'",
                 oom_cls.toString());
   testDone('testLibrariesMap');
 }
 
 void testMirrorSystem(MirrorSystem mirrors) {
   Expect.isTrue(mirrors.isolate.debugName.contains('main'));
@@ skipping 85 matching lines @@
   } on MirrorException catch (me) {
     saw_exception = true;
   }
   Expect.isFalse(saw_exception);
   Expect.equals("InstanceMirror on instance of 'MyClass'", mirror.toString());
 
   ClassMirror cls = mirror.type;
   Expect.isTrue(cls is ClassMirror);
   Expect.equals('MyClass', cls.simpleName);
   Expect.equals('MySuperClass', cls.superclass.simpleName);
-  Expect.isTrue(cls.defaultFactory === null);
+  Expect.isTrue(cls.defaultFactory == null);
   Expect.equals('isolate_mirror_local_test', cls.owner.simpleName);
   Expect.isTrue(cls.isClass);
   Expect.equals('MyInterface', cls.superinterfaces[0].simpleName);
   Expect.equals("ClassMirror on 'MyClass'",
                 cls.toString());
 
   // Invoke mirror.method(1000).
   mirror.invoke('method', [ 1000 ]).then(
       (InstanceMirror retval) {
         Expect.equals('int', retval.type.simpleName);
@@ skipping 96 matching lines @@
   // Test that an isolate can reflect on itself.
   mirrorSystemOf(exit_port.toSendPort()).then(testMirrorSystem);
 
   testIntegerInstanceMirror(reflect(1001));
   testStringInstanceMirror(reflect('This\nis\na\nString'));
   testBoolInstanceMirror(reflect(true));
   testNullInstanceMirror(reflect(null));
   testCustomInstanceMirror(reflect(new MyClass(17)));
   testMirrorErrors(currentMirrorSystem());
 }