Mocha vs uvu

Mocha is a free, open-source JavaScript test framework that runs in Node.js and browsers. Tests run serially by default, and uncaught exceptions are associated with their test cases. Asynchronous tests can use callbacks or returned promises, while parallel execution is available in Node.js but not in browsers. The command-line interface defaults to the BDD interface and spec reporter; browser runs default to the HTML reporter, and reporters can be configured. Installation as a development dependency is documented for npm, pnpm, and yarn. Mocha 12 requires Node.js ^20.19.0 or >=22.12.0, and browser builds document support for evergreen Chrome, Edge, Firefox, and Safari. It supports JavaScript and TypeScript, parameterized cases, and lists editor-related packages for TextMate, JetBrains IDEs, Wallaby.js, Emacs, and VS Code. Built-in mocks are not included. The project points users to Discord and documentation explainers for more information.

uvu is a free, lightweight test runner for Node.js and browser projects. It supports individually executable test files, asynchronous tests that may return Promises, native ES modules and a familiar API. Tests can be grouped into named suites or registered through a simpler test interface, and snapshot testing is supported. Each file is self-contained and can also be run directly with Node.js. The optional CLI collects and executes suites, with options to stop after the first failure, ignore patterns, preload modules, set a working directory and colorize output. When a directory is specified, file matching takes a regular-expression pattern rather than relying on glob patterns. The optional assertion module works in browsers and can be swapped for another library, including Node.js’s native assert. Installation uses `npm install --save-dev uvu`. Package metadata specifies Node.js version `>=8`; the repository identifies the project as MIT licensed and credits Luke Edwards.