What it does
Mocha is a JavaScript test framework for Node.js. Its default BDD interface uses `describe` and `it`, and its hook functions provide setup and cleanup around tests. Mocha leaves assertion style and related tools to the project; the current getting-started guide specifies supported Node.js versions.
Install Mocha as a development dependency, create test files with describe and it, then invoke npx mocha or add it to the package test script. The official example uses Node’s assert module, but projects can select their own assertion library. Use before, after, beforeEach, and afterEach when tests need shared setup or cleanup.
The current guide requires Node.js ^20.19.0 || >=22.12.0. Mocha supplies the runner and interfaces, not every choice in a test stack, so add assertions, browser drivers, or other helpers according to what the project tests. The official repository is MIT-licensed; the documentation site separately identifies its content as CC BY 4.0.
Strengths
- The guide supports npm, pnpm, and yarn installation and shows CLI or package-script use.
- Lifecycle hooks make shared setup and cleanup explicit.
- The official software repository uses the MIT License.
Watch out for
- The current guide requires Node.js `^20.19.0 || >=22.12.0`.
- Projects choose and configure assertion and other testing tools separately.
Best for
- Running Node.js test suites with explicit control over assertions and supporting tools
- Tests that need asynchronous behavior and reusable setup or cleanup hooks
Sources
- Getting Started | Mocha (Oct 25, 2026)
- Hooks | Mocha (Oct 25, 2026)
- LICENSE | mochajs/mocha (Oct 25, 2026)