pkg/unittest: Run tests in zones

tests/html/events_test.dart

 // Copyright (c) 2013, 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 tests.html.events_test;
 
 import 'dart:async';
 import 'dart:html';
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
@@ skipping 53 matching lines @@
     expect(invocationCounter, isZero);
 
     provider.forTarget(element).listen(handler);
     invocationCounter = 0;
     element.dispatchEvent(event);
     expect(invocationCounter, 1);
 
     provider.forTarget(element).listen(handler);
     invocationCounter = 0;
     element.dispatchEvent(event);
-    expect(invocationCounter, 1);
+
+    // NOTE: when run in a custom zone, the handler is wrapped
+    // The logic for html events which ensures identical handlers are added only
+    // once is therefor muted by the wrapped handlers.
+    // Hence, we get different behavior depending on the current zone.
+    if(Zone.current == Zone.ROOT) {
+      expect(invocationCounter, 1);
+    } else {
+      expect(invocationCounter, 2);
+    }
   });
 
   test('InitMouseEvent', () {
     DivElement div = new Element.tag('div');
     MouseEvent event = new MouseEvent('zebra', relatedTarget: div);
   });
 
   test('DOM event callbacks are associated with the correct zone', () {
     var callbacks = [];
 
@@ skipping 16 matching lines @@
           expect(Zone.current, equals(zone));
           sub.cancel();
         }));
       }
 
       sub = element.on['test'].listen(expectAsync1(handler));
     }));
     element.dispatchEvent(new Event('test'));
   });
 }