Bug: `startTransition` doesn't work with `useSyncExternalStore` about react

[gaearon]

A useSyncExternalStore update can't be a transition — that's why it's a "sync" external store. Only React-managed state like useState or useReducer can be updated in a transition. That's the tradeoff of useSyncExternalStore, and why it's only recommended to use if you can't let React drive the state updates.

[josepot]

Hi @gaearon!

First and foremost: thanks a lot for such a quick replay!

Yeah, I suppose that makes sense. I actually suspected that could have been the case. However, I did check in the docs and there was no mention of this on the "caveats" section of the startTransition docs, nor anywhere else on the docs of usSyncExternalStore. So yeah, that combined with the fact that the error is a bit misleading, made me think that perhaps this was a bug.

Please understand that I'm not complaining, I'm just sharing this feedback so that these things can be improved. Although, I'm sure that you must have bigger fish to fry. Anyways, I will try to find some time during this week to open a PR to -at least- try to improve the docs.

Thanks again!