[acdlite]

We have a mechanism to handle this exact scenario. We classify certain user input events, like keypresses and clicks, as "discrete" events. Updates that are triggered from discrete event will always be processed sequentially. We don't batch multiple events. Although we do batch multiple setStates within the same event, which is different. "Automatic batching" refers to the updates themselves, not the events.

We call non-discrete events (like mousemove) "continuous", and for those we will batch updates across multiple events.

We've been testing this at Facebook for a while and we think our model is really solid, handling all the common cases and a bunch of edge cases, too. If you try it out and find something unexpected, please let us know and we'll fix it!

[Sammi]

That does sound like React is doing a lot of work to work around some issue. As OP said: "This is an example of React doing too much."

[acdlite]

I agree the React implementation is very complex, but in a way that's by design: we add features to React when it allows us to move complexity out of our product code and into a framework.

Like, yes, implementing batching in React was complicated, but in exchange the developer doesn't have to think about it anymore. It just works!