DestroyOnUnregister incompatible with StrictMode in React18 about react-final-form HOT 2 OPEN

Strict Mode is a Breaking Change in React 18...
It emulates unmounting and remounting the fields which would then obviously clear all the values from the formState.

There are workarounds out there e.g. https://blog.ag-grid.com/avoiding-react-18-double-mount/

Willing to accept a PR that fixes this behaviour.

from react-final-form.

Hi!
I recently did a project on which we relied a lot on destroyOnUnregister and I'd be hard to implement the same feature with a FormSpy so I looked into your suggestion.

It's a bit complicated to try and handle correctly the behavior when you have dependencies or changing effect function ( the code in the link broke quite a lot of tests in final-form

I've managed to have a version that works here ( and for which the tests passes on react-final-form )
https://github.com/Axnyff/useEffectOnceInStrictMode/blob/main/useEffectOnceInStrictMode.ts
with some tests here
https://github.com/Axnyff/useEffectOnceInStrictMode/blob/main/useEffectOnceInStrictMode.test.js

I'm not sure I'm not missing some weird edge cases that would break the regular behavior of useEffect.
It seems to fix the behavior of destroyOnUnregister if I only fix that useEffect: https://github.com/final-form/react-final-form/blob/main/src/useField.js#L113

It looks like it would be hard to bring the tests in react-final-form as they are only valid for react 18.
Do you think there's a way I can do a PR to fix that behavior ?

from react-final-form.