Mocha vs Rstest

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.

Rstest is a free, open-source testing framework for JavaScript and TypeScript, built on Rsbuild and Rspack. It bundles tests through Rspack’s dependency-graph build process and applies SWC transforms. Projects can reuse configuration from Rsbuild, Rslib, or Rspack, including aliases, transforms, and plugins. Tests run in Node.js, simulated DOM environments with jsdom or happy-dom, and real browsers. Browser Mode uses Playwright to run tests in Chromium, Firefox, and WebKit; an integration supports end-to-end tests against local, preview, or deployed URLs. Rstest can also load Module Federation remotes in Node, JSDOM, and Browser Mode. Its built-in tools include Jest-compatible assertions, snapshots, mocks, spies, lifecycle hooks, file-level isolation, reporters, filtering, and coverage reporting. For CI, it supports multi-project testing, sharding, blob report merging, and coverage thresholds. The Rstack VS Code extension lets users browse, run, and debug tests. The quick start requires Node.js 20.19.0 or newer, and recommends the Node.js LTS version. Rstest is released under the MIT license.