for discussion: support for zones in DOM events

tests/html/events_test.dart

-library EventsTest;
-import '../../pkg/unittest/lib/unittest.dart';
-import '../../pkg/unittest/lib/html_config.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';
 
 main() {
   useHtmlConfiguration();
 
   test('TimeStamp', () {
     Event event = new Event('test');
 
     int timeStamp = event.timeStamp;
     expect(timeStamp, greaterThan(0));
   });
@@ skipping 50 matching lines @@
     provider.forTarget(element).listen(handler);
     invocationCounter = 0;
     element.dispatchEvent(event);
     expect(invocationCounter, 1);
   });
 
   test('InitMouseEvent', () {
     DivElement div = new Element.tag('div');
     MouseEvent event = new MouseEvent('zebra', relatedTarget: div);
   });
+
+  test('DOM event callbaccks are associated with the correct zone', () {
+    var callbacks = [];
+    runZonedExperimental(expectAsync0(() {
+      final element = new Element.tag('test');
+      element.id = 'eventtarget';
+      document.body.append(element);
+
+      int asyncCounter = 0;
+      var asyncCallback = expectAsync0(() {
+        asyncCounter++;
+      });
+
+      void handler(Event e) {
+        expect(e.type, equals('test'));
+        Element target = e.target;
+        expect(element, equals(target));
+
+        runAsync(asyncCallback);
+      }
+
+      var provider = new EventStreamProvider<CustomEvent>('test');
+      var sub = provider.forTarget(element).listen(expectAsync1(handler));
+      element.dispatchEvent(new Event('test'));
+
+      expect(callbacks.length, 1, reason: 'event was run in a zone.');
+      expect(asyncCounter, 0, reason: 'callback was not invoked yet.');
+      callbacks.first();
+      expect(asyncCounter, 1, reason: 'callback was invoked.');
+      sub.cancel();
+    }), onRunAsync: (x) {
+      callbacks.add(x);
+      return x;
+    });
+  });
 }