Most parts of ESLint have unit tests associated with them. Unit tests are written using Mocha and are required when making contributions to ESLint. You'll find all of the unit tests in the
When you first get the source code, you need to run
npm install once initially to set ESLint for development. Once you've done that, you can run the tests via:
This automatically starts Mocha and runs all tests in the
tests directory. You need only add yours and it will automatically be picked up when running tests.
Running Individual Tests
If you want to quickly run just one test, you can do so by running Mocha directly and passing in the filename. For example:
npm run test:cli tests/lib/rules/no-wrap-func.js
Running individual tests is useful when you're working on a specific bug and iterating on the solution. You should be sure to run
npm test before submitting a pull request.
More Control on Unit Testing
npm run test:cli is an alias of the Mocha cli in
./node_modules/.bin/mocha. Options are available to be provided to help to better control the test to run.