Mocha
Mocha is a feature-rich JavaScript test framework that runs on Node.js and in the browser, providing a flexible and simple API for writing asynchronous tests. It supports various assertion libraries, such as Chai, and offers built-in test reporters for clear output. Mocha is widely used for unit, integration, and end-to-end testing in JavaScript applications.
Developers should learn Mocha when building JavaScript applications that require reliable testing to ensure code quality and prevent regressions, especially in Node.js or browser-based projects. It is ideal for teams needing a customizable testing setup with support for different assertion styles and asynchronous operations, commonly used in conjunction with tools like Chai for assertions and Sinon for mocking.