React 19 support

[bmv437]

Hi there. I noticed when attempting to upgrade to React 19 that the functionality of react-keyed-flatten-children stopped working.

I've forked the codesandbox example in the README and upgraded it to React 19 as a reproduction:
https://codesandbox.io/p/sandbox/react-keyed-flatten-children-example-forked-tq55fj

Are there any plans for this package to support React 19?

[alfonsusac]

I've tested Children.forEach with React 19 but not with this library.

The problem lies with how async components are handled in Children array methods

It seems that even though based on the source code async components are handled it doesn't seem to work in practice.

Passing a promised component into Children array methods will hang the entire browser.

[grrowl]

Tracked it down to facebook/react#31688 — react-is needs to be >=19 to work with React 19. I'll ship an update to react-keyed-flatten-children today :)

Thanks for the great report!

[grrowl]

Here's a fork of the codesandbox with the correct behaviour https://codesandbox.io/p/sandbox/react-keyed-flatten-children-example-forked-tq55fj

[grrowl]

Fixed in #21 and v3.1.0 — we maintain existing React 15+ support at runtime, and this upgrades our test suite to React 19. Thanks again!

[bmv437]

Thanks @grrowl for getting this fix out, and super happy to see it maintains backward compatibility!

[benface]

I agree, thank you so much for the amazing work on this library, both @grrowl and @bmv437. Unfortunately, it looks like there is a backward compatibility issue with this change, I filed an issue at #22. No big deal, I will pin my version to 3.0.2 for now, and maybe I'll have time to look into it if nobody does first. Thanks again!

[grrowl]

Ah my apologies @benface can you confirm which version of React you're seeing this in? Ideal would be a codesandbox reproduction of the issue, I will have time to look into this Monday 🤞

[benface]

Hey, still on React 18 here. I will try to reproduce in CodeSandbox soon and will update the issue when I have done so. Thank you!