Jest is a comprehensive testing framework for JavaScript. Though it is more commonly known for testing React components, it can be used for general-purpose testing with any JavaScript library or framework. Among the many JavaScript testing solutions in Jest, it provides support for mocking and snapshot testing, comes with an assertion library, and tests in Jest are written in the behavior driven development (BDD) style. Besides testing the React components, Jest can be also be adapted to write test code for the Node-Express-Mongoose-based backend as required. Hence, it is a solid testing option to add test code for the MERN applications.
To learn more about Jest, read the docs at https://facebook.github.io/jest/docs/en/getting-started.html ...
