Unit tests are essential for increasing the test coverage of a backend application, ensuring its reliability, functionality, and robustness. Jest has

Unit Testing in Node.js With Jest

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2024-11-27 16:00:07

Unit tests are essential for increasing the test coverage of a backend application, ensuring its reliability, functionality, and robustness. Jest has become one of the most popular solutions when unit testing in Node, due to its intuitive API, zero-configuration philosophy, and flexible approach to code transpilation.

Jest is a free, open-source JavaScript testing framework that checks the correctness of your codebase. It is focused on simplicity with a zero-config approach. It works with backend applications built in Node.js as well as frontend applications in React, Angular, Vue, and more. When it comes to code transpilation, it integrates natively with Babel, Vite, Parcel, and webpack.

At the time of writing, Jest boasts over 44.3k stars on GitHub and over 30 million weekly downloads on npm. These impressive figures place Jest among the top testing libraries in the JavaScript ecosystem.

By default, a Jest test is a JavaScript or TypeScript file with the .test.{js,jsx,ts,tsx} or .spec.{js,jsx,ts,tsx} extension. Unless configured otherwise, Jest automatically looks for test files in the __tests__ directory or any sub-folder inside your project's root folder.