Switch to IS_REACT_ACT_ENVIRONMENT instead of act when needed when using react 18

[AugustinLF]

Closes #1093. Implementation is copied from testing-library/react-testing-library#1031

Without the react 17/18 branches (i.e only using the new API), tests pass but are full of console.error related to act and async act. With his new implementation, everything passes (including the new tests that used to fail on react 18), without calls to console.error.

[mdjastrzebski]

@AugustinLF big WOW for creating this PR 🚀

I've done some cursory review and left few comments, I plan to dig a bit deeper into that, as the PR is quite complex.

[AugustinLF]

@mdjastrzebski I've updated the PR with your feedback, let me know if you need anything else :)

[mdjastrzebski]

Almost there 🚀 , looking forward to merging that :-)

[AugustinLF]

We're good @mdjastrzebski :)

[mdjastrzebski]

@AugustinLF It seems I've broken build by pushing a simple commit that adds one line for formatting. Can you add some minimal commit so that the build is triggered as your user?

[mdjastrzebski]

Looks great! Though I've broke the build by adding an empty line for formatting purpose.

[AugustinLF]

@mdjastrzebski fixed, added an empty commit!

[thymikee]

I wish React team documented this better. This horrific experience for testing library authors.

[AugustinLF]

I wish React team documented this better. This horrific experience for testing library authors.

Yeah, the documentation was there in the WG, but not in the main release notes, so a bit sketchy.

@mdjastrzebski what do you think of creating an RC release of that? I'm currently working on our react 18 upgrade and that'd be some good battle testing.

[mdjastrzebski]

Going through RC sounds good, for extra safety.

From our analysis of both RTL and React 18 code with @thymikee , we came to conclusion that IS_REACT_ACT_ENVIRONMENT option affects only logging of sync act error messages.

In short:
IS_REACT_ACT_ENVIRONMENT === false
=> isReactActEnvironmentGlobal === false`
=> !isLegacyActEnvironment
=> disable sync act warning in React

[AugustinLF]

Yes. But on top of that we updated the implementation of waitFor:

// from
let result: T;
await act(async () => {
  result = await waitForInternal(expectation, optionsWithStackTrace);
});

// to
await waitForInternal(expectation, optionsWithStackTrace);

[mdjastrzebski]

@AugustinLF we will make the release after the weekend, as I need @thymikee for npm publish access rights.

[mdjastrzebski]

🎉 This PR is included in version 11.2.0 🎉