How to programmatically fire a dblclick event defined with addEventListener?

Question

For JS Unit test, I need to check that a double-click behaves as expected. The issue is that the event was registered via element.addEventListener. And for some reason, in this case, element.ondblclick() does not work. HTML:

<input type="image" src="pic.jpg" id="aa"/>

Javasript:

document.getElementById('aa').addEventListener("dblclick", function(){alert('aa')});
document.getElementById('aa').ondblclick();

Fiddle: http://jsfiddle.net/prZKy/

If you double click on the image, it works, but the ondblclick() in the javascript does not work.

Anyone has an idea on how to do it?

Answer 1

You can use dispatchEvent to programatically trigger events:

var event = new MouseEvent('dblclick', {
    'view': window,
    'bubbles': true,
    'cancelable': true
  });
document.getElementById('aa').dispatchEvent(event);

See the section "Triggering built-in events" on MDN.

Here is a fiddle of the code in action.