unwrap gets stuck in errored state and can't recover

[darrenclark]

Bug Description

It seems unwrap can get stuck in an errored state and never recover, even if the underlying atom changes to a Promise that resolves successfully.

Cause

jotai/src/vanilla/utils/unwrap.ts

Lines 56 to 62 in 4661064

	const promiseAndValueAtom: WritableAtom<PromiseAndValue, [], void> & {
	init?: undefined
	} = atom(
	(get, { setSelf }) => {
	get(refreshAtom)
	const prev = get(promiseAndValueAtom) as PromiseAndValue | undefined
	const promise = get(anAtom)

I think the const prev = get(promiseAndValueAtom) line will always end up re-throwing the previous error (and it loses the dependency on the underlying atom as well, since it exits before const promise = get(anAtom) on the next line)

Potential Solution

Adding a try/catch around it seems to fix the issue, I've got a commit here: darrenclark@3d0ff77 (includes test case that reproduced the issue)

If that fix makes sense, I'll open a PR!

Reproduction Link

darrenclark@3d0ff77

[dai-shi]

Thanks for reporting. I think the fix makes sense. Please open a PR and see if CI passes.

[darrenclark]

No problem! PR is up here: #3163

[darrenclark]

@dai-shi Is there anything else I can help out with on my end?

We're facing some issues with unwrap in our app, so happy to help out wherever I can to move things along!

[dai-shi]

Sorry for the delay. I was just busy. There are many PRs on pile. Will work on them soon.