Failed to pass tests with latest React experimental builds

[dai-shi]

#1497 reveals that a test fails with versions between:
https://www.npmjs.com/package/react/v/0.0.0-experimental-79c582981-20221021
and
https://www.npmjs.com/package/react/v/0.0.0-experimental-fecc288b7-20221025.

[dai-shi]

facebook/react@65e32e5...79c5829

We probably need to use use.

[dai-shi]

#1512 still fails.
I'm not sure if the problem is on our end, or react, or testing-library.

Can anyone help?

[manakuro]

It seems like some tests in tests/utils/atomWithObservable.test.tsx got stuck while executing. I'm going to dig into that.

jotai/tests/utils/atomWithObservable.test.tsx

Line 139 in 820f2f1

await findByText('count: 9')

[manakuro]

Turns out that the promise inside atomWithObservable is still pending after resolving, then the process got stuck.

jotai/src/utils/atomWithObservable.ts

Line 84 in a85c1f7

resolve?.(result)

This causes only when the initialValue is not passed and the promise is used.

[email protected] executes rendering after the promise is resolved, but [email protected] doesn't. I guess it's related to the changes on [email protected].
facebook/react#25523

it works in the browser environment, though.
https://codesandbox.io/s/react-typescript-forked-forked-nr4wuk?file=/src/App.tsx

I will continue to work on that.

[manakuro]

@dai-shi
This behavior occurs when you use jest.useFakeTimers and promise inside custom hooks. The rendering process got stuck while flushing the process inside the act. The cause of this might have something to do with the PR. I reported it, so we can keep track of what's going on.

facebook/react#25523 (comment)

As another option, we could flush the promises manually like this.
https://github.com/manakuro/test-react-experimental/pull/1/files

But still, there are some tests that got stuck in the tests/utils/atomWithObservable.test.tsx, so I need to figure this out.

[dai-shi]

@manakuro Could facebook/react#26512 be related or not?

[manakuro]

@dai-shi I'm not sure the facebook/react#26512 has anything to do with our issue, but the new version, 18.3.0-next-1308e49a6-20230330 seems to have solved the fake timer issue. I have no idea, but it might be related to the changes.
facebook/react@4111002...1308e49

Please take a look at my PR.
#1860