Support for CustomEvent (and the general plan for Level 3 support)

Hi,

I noticed jsdom doesn’t support Level 3 custom events, so the following code crashes:

var tap = document.createEvent('CustomEvent');
tap.initCustomEvent('tap', true, true, {});

It would be relatively trivial to add a basic empty implementation in the level 2 folder (baaaaad), but I wouldn’t know where to start with Level 3 (everything is commented-out). What’s the plan in that area?

On a related topic, the new standard seems to be using event constructors instead of initCustomEvent. Does that fit into Level 4 support?

var event = new Event('focus', {bubbles:false,cancelable:true});
document.querySelector('input').dispatchEvent(event);

[treshugart]

@rprieto I found that doing something like the following worked for my purposes:

function createCustomEvent (name, opts = {}) {
  let e = document.createEvent('HTMLEvents');
  e.detail = opts.detail;
  e.initEvent(name, opts.bubbles, opts.cancelable);
  return e;
}

[domenic]

Fixed by https://github.com/tmpvar/jsdom/commit/5459bec38660658e4e18642265f61c3d79e984dd