jest runs all tests found in monorepo react-scripts@2.0.0-next

[bugzpodder]

Jest currently runs all tests it can find in every workspace in the monorepo (spec/tests) when ran from CRA workspace.
This is somewhat unexpected, and can be problematic:

• jest version mismatches can break tests
• jest snapshots can potentially record different things depending on configuration

If needed I can try to get a clean repro up.

[bugzpodder]

It has some really weird effects, such as if you have a cypress directory for e2e under the CRA app directory, jest would skip them but if you have a cypress directory in a imported workspace, jest would happily decide to run it and fail.

[bugzpodder]

This is likely related to #3967

[bradfordlemley]

@bugzpodder The current 2.0 implementation assumes that you want all workspaces in the monorepo to be treated as part of your app source (transpiled, linted, and tested), there is no way to opt in or out. #4092 proposes to fix this by requiring workspaces to be opted in.

It's not clear if that would fix your use cases, though. (e.g, Are you wanting to transpile the other workspaces, but not run their tests?) What do you think?

(BTW, as a workaround for the current issue, you should be able to give a pattern to the test command, e.g. react-scripts test myapp to avoid running tests from other workspaces.)

[SavePointSam]

Thanks for the quick scoping fix! Though I totally agree there should be a better way to go about this before 2.0.

EDIT: scoping isn't a great long-term solution as hitting a during the test suite will revert to all tests in the monorepo.