Preact: forceUpdate should take a callback

[Stuk]

As per the React API docs

[developit]

Good catch! This is a strange one since forceUpdate() is always synchronous, so there is no real purpose to the callback. However, it should be cheap/free to add (just duplicating this line) so we're probably fine to add it.

[Stuk]

I think it's because React queues all component updates (e.g. in setState) and so in React it may not happen synchronously.

[developit]

I don't see anything in their docs about it, but maybe it's something preact is doing unnecessarily. Perhaps forceUpdate() doesn't need to be synchronous and just has to bypass shouldComponentUpdate()...

[developit]

Released in 8.