$animate.flush() does not flush $animateCss animations in queue

[wesleycho]

We have an issue in angular-ui/bootstrap#4493 where it turns out that $animate.flush() does not flush the animations queued up by $animateCss, so the expandDone callback in the promise chain never fires in the collapse directive, which is causing some testing problems.

In particular, the .then callback in the promise returned by $animateCss(...).start() never gets called because there is no mechanism in ngMock for flushing out the queued animation.

[matsko]

I think it may be best to include a flushRunningAnimations method instead that does this plus everything that flush. We could also have another method called flushCallbacks that does this and have flush handle flushing pending animations as well as their associated callbacks.

[matsko]

@petebacondarwin and @IgorMinar what do you gentlemen you think?

[wesleycho]

Should note we were able to work around it by changing to finally, but it probably is a good thing to implement a solution at some point.