javascript - How to use ESLint with Jest

Question

I'm attempting to use the ESLint linter with the Jest testing framework.

Jest tests run with some globals like jest, which I'll need to tell the linter about; but the tricky thing is the directory structure, with Jest the tests are embedded with the source code in __tests__ folders, so the directory structure looks something like:

src
    foo
        foo.js
        __tests__
            fooTest.js
    bar
        bar.js
        __tests__
            barTest.js

Normally, I'd have all my tests under a single dir, and I could just add an .eslintrc file there to add the globals... but I certainly don't want to add a .eslintrc file to every single __test__ dir.

For now, I've just added the test globals to the global .eslintrc file, but since that means I could now reference jest in non-testing code, that doesn't seem like the "right" solution.

Is there a way to get eslint to apply rules based on some pattern based on the directory name, or something like that?

Answer 1

The docs show you are now able to add:

"env": {
    "jest/globals": true
}

To your .eslintrc which will add all the jest related things to your environment, eliminating the linter errors/warnings.

You may need to include plugins: ["jest"] to your esconfig, and add the eslint-plugin-jest plugin if it still isn't working.