Crash on updateConfiguration method

[stephenyao]

We're using this component and getting the occasional crash upon calling updateConfiguration inside the InfiniteScrollingBehavior class.

The scenario is as we have a vertically scroll UICollectionView where each cell in the collection view contains another collection view that uses the InfiniteScrollingBehaviour class. Each time we deque and reuse a cell we need to call updateConfiguration on the InfiniteScrollingBehavior, and this is where the crash occurs. We can't reproduce it 100% of the time, but it happens frequently enough that it would blow up in production if we were to release it.

I'm suspecting that

DispatchQueue.main.asyncAfter(deadline: .now() + 0.01) {
    self.collectionView.reloadData()
    self.scrollToFirstElement()
}

is causing the problem. May I ask, why you have used a asyncAfter call, rather than just a async? Also, why do we need to use DispatchQueue.main at all, as the InfiniteScrollingBehavior doesn't perform updateConfiguration on a background queue?