So these tests are testing the asides, which are only fully displayed after a transition is applied. 

The tests do, admittedly, test :visible (which the aside probably is if it's been triggered).

But what happens from a user's perspective is that the tap the aside and, after a moment, it is displayed. Therefore the sleep is really in there to mimic the user's experience (imagine that the aside is shown for a moment and then it disappeared because of magic). You could read it as testing that "the user taps the aside and, after it's shown, it's still there" :cat: 

Clearer?