How to Use Node.js Test Runner: A Detailed Guide

The Node.js test runner is a built-in tool for automating testing in JavaScript projects. It was introduced in Node.js version 18 and became stable in version 20. The test runner offers features such as an assertion library, test hooks, mocking functionality, code coverage, and test reporters. It streamlines the testing process by saving time on deciding which tool to use and simplifies the process of writing tests without needing additional libraries. Node.js test runner also supports parallel testing and allows skipping tests. Additionally, it provides various test hooks like before(), beforeEach(), after(), and afterEach() for setting up and cleaning up the testing environment. The mocking functionality enables creating spies and stubs to isolate tests from external dependencies or third-party packages during testing situations.