Custom Event requires a polyfill to work

I'm not sure if this is a grunt-casper issue versus a casperjs issue, but the CustomEvent method was not working for me through casper.evaluate:

casper.evaluate(function(){
var obj = document.createElement('div');
obj.addEventListener("cat", function(e) { console.log(e.detail) });
var event = new CustomEvent("cat", {"detail":{"hazcheeseburger":true}});
obj.dispatchEvent(event);
});

I finally got it to work by implementing this polyfill on the page I was testing:

(function () {
function CustomEvent ( event, params ) {
params = params || { bubbles: false, cancelable: false, detail: undefined };
var evt = document.createEvent( 'CustomEvent' );
evt.initCustomEvent( event, params.bubbles, params.cancelable, params.detail );
return evt;
};

CustomEvent.prototype = window.Event.prototype;

window.CustomEvent = CustomEvent;
})();

I thought I'd point it out as this caused me a few hours of grief, and I'd thought it might save someone some time.

iamchrismiller / grunt-casper

Custom Event requires a polyfill to work #50