Bug: global.IS_REACT_ACT_ENVIRONMENT = false does not work

[anilanar]

Potentially related to using jest. Didn't confirm.

React version: 18.2.0

Steps To Reproduce

1. Clone https://github.com/anilanar/react-18-act-env ; which is a create-react-app with an adjustment to App component to trigger an async setState and an adjustment to the test to wait for that async state update.
2. npm install
3. npm test -- --watchAll

The current behavior

It logs Warning: An update to App inside a test was not wrapped in act(...).

The expected behavior

It does not log that warning.

[eps1lon]

@testing-library/react automatically sets it. I haven't really thought about how you would use @testing-library/react without relying on act.

Though you should file this in https://github.com/testing-library/react-testing-library/ instead since React can't do anything here.