Intern vs Rstest

Intern is a free, open-source test system for JavaScript libraries and applications. It supports unit and functional testing, with tests written in JavaScript or TypeScript using TDD or BDD styles. Tests can run in Node.js, web browsers, or across multiple browsers and platforms through the Intern runner, with parallel execution and code coverage reporting. The project can target web pages and native or hybrid iOS and Android applications. For browser automation, it supports WebDriver-compatible tools and services, including Selenium, Appium, and Selendroid. Listed cloud options include Sauce Labs, BrowserStack, TestingBot, and a user’s own Selenium Grid. Continuous-integration integrations include Travis CI, Jenkins, and TeamCity. Intern’s extensible architecture allows custom test interfaces, executors, and reporters. It runs on Android, iOS, Linux, macOS, self-hosted environments, the web, and Windows. Installation is provided through npm, and the project uses the New BSD license.

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.