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.

Read More: http://facebook.github.io/jest/