fix(jqLite): pass in a dummy event with triggerHandler

Previously, anchor elements could not be used with triggerHandler because
triggerHandler passes null as the event, and any anchor element with an empty
href automatically calls event.preventDefault(). Instead, pass a dummy event
when using triggerHandler, similar to what full jQuery does. Modified from
PR angular#2379.

Author: juliemr

src/jqLite.js

@@ -54,7 +54,7 @@
  * - [replaceWith()](http://api.jquery.com/replaceWith/)
  * - [text()](http://api.jquery.com/text/)
  * - [toggleClass()](http://api.jquery.com/toggleClass/)
- * - [triggerHandler()](http://api.jquery.com/triggerHandler/) - Doesn't pass native event objects to handlers.
+ * - [triggerHandler()](http://api.jquery.com/triggerHandler/) - Passes a dummy event object to handlers.
  * - [unbind()](http://api.jquery.com/unbind/) - Does not support namespaces
  * - [val()](http://api.jquery.com/val/)
  * - [wrap()](http://api.jquery.com/wrap/)
@@ -743,9 +743,18 @@ forEach({
 
   triggerHandler: function(element, eventName) {
     var eventFns = (JQLiteExpandoStore(element, 'events') || {})[eventName];
+    var event;
+
+    if (document.createEventObject) {
+      event = document.createEventObject();
+      event.type = eventName;
+    } else {
+      event = document.createEvent('HTMLEvents');
+      event.initEvent(eventName, false, true);
+    }
 
     forEach(eventFns, function(fn) {
-      fn.call(element, null);
+      fn.call(element, event);
     });
   }
 }, function(fn, name){

test/jqLiteSpec.js

@@ -1128,6 +1128,19 @@ describe('jqLite', function() {
       expect(clickSpy1).toHaveBeenCalledOnce();
       expect(clickSpy2).toHaveBeenCalledOnce();
     });
+
+    it('should pass a dummy event', function() {
+      var element = jqLite('<a>poke</a>'),
+          pokeSpy = jasmine.createSpy('poke'),
+	  event;
+
+      element.bind('poke', pokeSpy);
+
+      element.triggerHandler('poke');
+      event = pokeSpy.mostRecentCall.args[0];
+      expect(event.type).toEqual('poke');
+      expect(event.preventDefault).toBeDefined();
+    });
   });