emberjs/ember.js — pull request #923 by joliss (2012-05-31 18:25:45+00:00)
Title: Assert

* Guard against undefined mixins

This can easily happen with Ember.Object.extend(App.DoesNotExist, {...}).

* Use Ember.assert instead of throw

* Guard against implicit function application by Ember.assert

mixin.js didn't previously use Ember.assert. Looking at https://github.com/emberjs/ember.js/blob/master/packages/ember-metal/lib/mixin.js#L7 , do we have to add any require statement to make sure it is available?