feature: allow ESM for test environment

[gilles-yvetot]

Summary

Support for native ESM has been included but we did not have the possibility yet to also use ESM for custom test environment

Test plan

I don't really know how to test that and I'd love some help on that

[gilles-yvetot]

Anyone here?

[SimenB]

Thanks, and sorry about the slow response!

In addition to the inline comment I made, this needs an integration test. You can look at e.g. #11163 where I added support for ESM transformers for inspiration for how to write the integration test

[SimenB]

(oops, previous review should have been "request changed")

[gilles-yvetot]

@SimenB I tried to add a dummy test. Simply create a simple ESM test environment and run a test with this environment.
I haven't worked on a repo that big so I'd probably need more guidance if that does not work :(

[gilles-yvetot]

@SimenB I'd love to be able to test on my local repo and potentially start using it until #11167 is merged in.

Running npm rm jest && npm i git+ssh://[email protected]:gilles-yvetot/jest#feature/10018 install @jest/monorepo.
Do you have any tips on how to start using my branch?

Thanks a lot

[SimenB]

@gilles-yvetot if you wanna test with a local build, we have instructions in CONTRIBUTING.md

[SimenB]

Look pretty good! You also need to add a test which actually runs the integration test - something like https://github.com/facebook/jest/blob/master/e2e/__tests__/nativeEsm.test.ts (see https://github.com/facebook/jest/blob/master/CONTRIBUTING.md#integration-tests)

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.