Jun 4, 2025 · Today we are happy to announce the release of Jest 30. This release features a substantial number of changes, fixes, and improvements. While it is one of the largest major releases …

Note: Jest documentation uses yarn commands, but npm will also work. You can compare yarn and npm commands in the yarn docs, here. Let's get started by writing a test for a hypothetical function that …

In your test files, Jest puts each of these methods and objects into the global environment. You don't have to require or import anything to use them. However, if you prefer explicit imports, you can do …

Note: babel-jest is automatically installed when installing Jest and will automatically transform files if a babel configuration exists in your project. To avoid this behavior, you can explicitly reset the …

Jest is a universal testing platform, with the ability to adapt to any JavaScript library or framework. In this section, we'd like to link to community posts and articles about integrating Jest into popular JS libraries.

Browse the docs Find what you're looking for in our detailed documentation and guides. Learn how to get started with Jest. Troubleshoot problems with Jest. Learn how to configure Jest. Look at the full …

You can cherry pick specific features of Jest and use them as standalone packages. Here's a list of the available packages:

See React: Function and Class Components. Reminders that with Class components, we expect Jest to be used to test props and not methods directly. Now let's use React's test renderer and Jest's …

The jest object is automatically in scope within every test file. The methods in the jest object help create mocks and let you control Jest's overall behavior. It can also be imported explicitly by via import from …

Jest adds the inlineSnapshot string argument to the matcher in the test file (instead of an external .snap file) the first time that the test runs. Check out the section on Inline Snapshots for more info.