Jest

🃏 Delightful JavaScript Testing

👩🏻‍💻 Easy Setup: Jest is a complete and easy to set up JavaScript testing solution. In fact, Jest works out of the box for any React project.
🏃🏽 Instant Feedback: Failed tests run first. Fast interactive mode can switch between running all tests or only test files related to changed files.
📸 Snapshot Testing: Jest can capture snapshots of React trees or other serializable values to simplify UI testing.