- Instant Feedback: Fast interactive watch mode runs only test files related to changed files and is optimized to give signal quickly.
- Snapshot Testing: Capture snapshots of React trees or other serializable values to simplify testing and to analyze how state changes over time.
- Fast and sandboxed: Jest parallelizes test runs across workers to maximize performance. Console messages are buffered and printed together with test results. Sandboxed test files and automatic global state resets for every test so no two tests conflict with each other.
- Built-in code coverage reports: Easily create code coverage reports using --coverage. No additional setup or libraries needed! Jest can collect code coverage information from entire projects, including untested files.
- Powerful mocking library: Jest has powerful mocking library for functions and modules. Mock React Native components using jest-react-native.