jest: --findRelatedTests don't find test file if path include special characters and file extension

I’ve found the issues. It has to do with the way file patterns are handled on windows. I’ve implemented a fix in #11548 (which also fixes #9728). This merely fixes the bug, it doesn’t add support for targeting directories.

@nicojs you rock 🥰

I’ve noticed that this only seems to affect Windows.

On Linux (WSL):

$ npx jest --findRelatedTests src/@core/my-lib.ts
 PASS  src/@core/my-lib.spec.ts
  Square method
    ✓ should be defined (2 ms)
    ✓ should return right value (3 ms)
    

$ npx jest --findRelatedTests 'src/@$_(ok)/my-lib.ts'
 PASS  src/@$_(ok)/my-lib.spec.ts
  Square method
    ✓ should be defined (2 ms)
    ✓ should return right value (2 ms)

I’ll try to debug to see what’s going on here.

While we’re at it: #9728 is also a big hurdle for StrykerJS users 😇

@blephy Thanks for all your hard work on this issue 🎉

StrykerJS uses --findRelatedTests to speed up jest test execution during mutation testing considerably (since StrykerJS knows exactly which file is mutated at a particular time, it specifies that file with --findRelatedTests), but you can turn this behavior off using { "jest": { "enableFindRelatedTests": false } }, so that is the current workaround for projects that have issues. See https://stryker-mutator.io/docs/stryker-js/jest-runner#configuration.

@blephy’s suggestion would work for us. We mostly need a “bugfree” version of --findRelatedTests. We only use the “full file path” (incl extension), so that would work.

However, from Jest’s point of view, it would be technically impossible to know the difference between path that includes a file extension vs one that doesn’t without performing disk IO. For example, “foo.bar” might refer to a file with name “foo” with extension “.bar”, or it could refer to a directory “foo.bar” which contains files. I would suggest the following:

• If the path contains “magic” (based on "testMatch" rules, see https://jestjs.io/docs/configuration#testmatch-arraystring)
  • Resolve the paths to directory entries (using node-glob or similar implementation)
• For each listed path:
  • Resolve to a directory entry.
    • If the directory entry resolves to a directory, search recursively in that directory for files with supported extensions that DO NOT match the testPattern regex (Note: this would be optional for StrykerJS).
    • If this directory entry resolves to a file, use that
• Run “findRelatedTest” lookup on all the resolved file paths and execute those files.

I like the suggestion.

cc @SimenB