How to get the native event?

[alvarocastro]

I created an implementation of this library for ember.js (github) and I'm trying to create unit tests for this.

I figured how to trigger a dragstart but have some issues creating the drop event. Altho I can trigger it, I don't know what data this library expects, couldn't find the native events in the callbacks and couldn't figure out how to debug the code inside the library since compilation seems to obfuscate it too much.