Jest is a JavaScript testing framework that provides a complete testing solution with built-in assertion libraries, mocking utilities, and snapshot testing capabilities. Developers use Jest to write and run unit tests, integration tests, and end-to-end tests with minimal configuration, making it especially useful for projects built with React or other JavaScript frameworks. It offers features like parallel test execution, code coverage reporting, and detailed error messages to help catch bugs early in development.

231 open issues · last updated Jul 21, 2026