Return a promise from setState

[anthonyshort]

This shouldn't be too hard. Just return a promise and resolve it on an event.

[anthonyshort]

I think we might just remove the callback from setState. Almost every use-case can be covered in afterUpdate. I can't think of anything that would benefit from it.

[yoshuawuyts]

agreed. if afterUpdate is the only thing that's triggered, well, after an update it makes for more transparent code. That also means there's no need to return a Promise.

[ivan-kleshnin]

@anthonyshort did you consider to make setState actually synchronous?
I mean to make it represent pending state and not rendered state.
It was discussed in React community many times https://groups.google.com/forum/#!msg/reactjs/R61kPjs-yXE/bk5AGv78RYAJ
but everything stucked because of backward compatibility issues.

I think your project is comparatively free to fix this design issue.
Hooks are mess and do not cover every usecase.

[anthonyshort]

@ivan-kleshnin We're definitely more free to make changes like this. In general I don't like the hooks, and I've found we rarely use them anyway. The only one I can see being useful would be something like afterRender so you could update some canvas element using the latest state.

I'm not sure I'm following the exact reasoning behind it yet though. What are the benefits to it? We don't access state on this so it probably wouldn't update the state object that gets passed in anyway.