Rstest vs uvu

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.

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.