How to run single test file in jest code example

Example 1: npm run only one test

n order to run a specific test, you'll need to use the jest command. npm test will not work. To access jest directly on the command line, install it via npm i -g jest-cli or yarn global add jest-cli.

Then simply run your specific test with jest bar.spec.js.

Note: You don't have to enter the full path to your test file. The argument is interpreted as a regexp. Any part of the full path that uniquely identifies a file suffices.

Example 2: jest run specific test

From the command line, use the --testNamePattern or -t flag:

jest -t 'fix-order-test'
This will only run tests that match the test name pattern you provide. It's in the Jest documentation.

Another way is to run tests in watch mode, jest --watch, and then press P to filter the tests by typing the test file name or T to run a single test name.

If you have an it inside of a describe block, you have to run

jest -t '<describeString> <itString>'