Our teams are delighted with the results of using Jest for front-end testing. It provides a ‘zero-configuration’ experience and has out-of-the-box features such as mocking and code coverage. You can apply this testing framework not only to React applications, but also to other JavaScript frameworks. One of Jest's often hyped features is UI snapshot testing. Snapshot testing would be a good addition to the upper layer of the test pyramid, but remember, unit testing is still the solid foundation.