Retsam Retsam - 1 month ago 16
Javascript Question

How to use ESLint with Jest

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

Pattern based configs are scheduled for 2.0.0 release of ESLint. For now, however, you will have to create two separate tasks (as mentioned in the comments). One for tests and one for the rest of the code and run both of them, while providing different .eslintrc files.

P.S. There's a jest environment coming in the next release of ESLint, it will register all of the necessary globals.