How do I use setupFiles in Jest?

How do I use setupFiles in Jest?

You can use the setupFiles configuration option in Jest to specify files that should be run before each test file. This is useful for setting up global variables or configurations.

Can you give me an example of how to set it up?

Sure! In your Jest configuration, you can add a setupFiles array. For example: setupFiles: ['<rootDir>/setupTests.js'].

What should I include in the setupTests.js file?

In setupTests.js, you can include any global setup code, like importing libraries or setting up mocks. For instance, you might import jest-fetch-mock to mock fetch calls.

Is there a way to run setup code only for specific tests?

Yes, you can use setupFilesAfterEnv for that purpose. It runs after the test framework is set up, allowing you to configure things specifically for certain tests.