React 19 Support?

[abubakriz]

Certain features from React 19 like useActionState and more currently do not work and therefore it is impossible to alias a react 19 project to preact

[JoviDeCroock]

That depends on whether or not you use these API's, what particular use case are you seeking to fill with useActionState that is outside of server-components/...? React 19 hasn't been out for long and we are still in conversations about the merit of some of these hooks

[bcomnes]

Are function refs with cleanup supported in preact?

[rschristian]

Yes, that landed in #4436

[abubakriz]

That depends on whether or not you use these API's, what particular use case are you seeking to fill with useActionState that is outside of server-components/...? React 19 hasn't been out for long and we are still in conversations about the merit of some of these hooks

useActionState is particulary useful, it eliminates a lot of boilerplate when it comes to form submission. It's true that you can do everything it does with the already existing hooks, but it's a lot cleaner IMO, and i've dropped libraries like react hook form thanks to it, (which also reduced my bundle size lol)

But most importantly, to me, preact has always been a tool that I can use as an alias for react to reduce my bundle size and improve my web app's experience, it would be a shame if that were not the case anymore

[JoviDeCroock]

I 100% understand that it's a convenient utility, and you are free to PR it if you like 😅 I haven't been able to deeply look into the nuances just yet.

[davidbonnet]

Mentioned in #2621 is the support for the ref prop, which React 19 now does. Any insights on whether work has started on this to avoid duplicate contributions?

[rschristian]

See #4617

[mayank99]

It might be difficult for Preact to fully support a lot of these new features, because actions build upon transitions. In theory, useActionState can be shimmed using useTransition. However, I was looking at the current implementation of useTransition in preact/compat and it always returns false for the pending state, which limits its usefulness.

preact/compat/src/hooks.js

Lines 64 to 66 in 055cc5b

	export function useTransition() {
	return [false, startTransition];
	}

useFormStatus would have a similar problem as well.

A good first step might be to start by supporting form action functions (i.e. <form action={() => {}}> and <button formAction={() => {}}>). These would effectively just call preventDefault in the form's onSubmit event handler.

[davidbonnet]

See #4617

Ah it's added to the v11 branch. Shall we consider v10 as well?

[rschristian]

Can't be done w/out a breaking change, however, #4623 added a new preact/compat/react-19 entry which you can use in your aliases to get access to it.

Edit: We reverted this for the time being.