Extend prefer-explicit-assert to report findBy* and waitFor

[zaicevas]

With prefer-explicit-assert enabled, getBy* usages without expect are reported, but findBy* and waitFor are not reported:

    screen.getByText('hey') // reported
    await waitFor(() => screen.getByText('hey')) // not reported
    await screen.findByText('hey') // not reported

What if we extended prefer-explicit-assert to report all of the above cases? 🤔

[Belco90]

Hey @zaicevas! Few comments about this improvement idea.

What about findBy* usage saving returned element within a var? That should not be reported.

Not really sure about reporting waitFor + getBy* query, since inside waitFor callback the user might have other necessary stuff there.

I'd go just for reporting findBy* usages for now. What do you think?

[zaicevas]

What about findBy* usage saving returned element within a var? That should not be reported.

Makes sense to me, since const foo = screen.getByText('hey') is not reported and there's no reason the behaviour should be different for findBy*

Not really sure about reporting waitFor + getBy* query, since inside waitFor callback the user might have other necessary stuff there.

Can you give an example to better understand what you have in mind?

I'd go just for reporting findBy* usages for now. What do you think?

Sure, I'd imagine these 2 cases having separate PRs anyway.

[Belco90]

Not really sure about reporting waitFor + getBy* query, since inside waitFor callback the user might have other necessary stuff there.

Can you give an example to better understand what you have in mind?

I don't have a really clear example in mind, to be honest. This is similar to no-unnecessary-act rule assuming there could be non-react-testing-library things inside act, in which case we need to allow.

This is a stupid example, but I'm not sure it should be reported:

const promiseA = new Promise()
const promiseB = new Promise()
// ...
await waitFor(async () => {
  await promiseA;
  await promiseB;
  screen.getByRole('button')
})

It's obvious it should be rewritten to just do await screen.findByRole('button') instead of the whole waitFor, but could be a legit case were using waitFor + awaiting promises + asserting with implicit getBy*? I think there must be for sure, so I'd say just leave the rule complaining about that standalone getBy* query should be enough.

What do you think?