Karma vs Pure Test

Karma is a JavaScript test runner that starts a web server, connects browsers, runs tests, and reports results to developers. It can watch configured files and rerun tests when they change. Plugins connect frameworks such as Jasmine, Mocha, and QUnit, alongside preprocessors, reporters, and browser launchers. Documented launchers include Chrome, Firefox, Safari, PhantomJS, JSDOM, Opera, Internet Explorer, SauceLabs, and BrowserStack. A browser on another device on the same network, including a phone or tablet, can be captured by visiting the Karma server URL. Karma runs on Node.js and is distributed as an npm package; its installation guide recommends installing it locally in a project. Documentation includes integration guides for Travis CI, Jenkins, and Semaphore CI. The project describes Karma as primarily designed for low-level unit testing and points to Protractor for high-level testing. Karma is free and MIT-licensed, but deprecated: it accepts no new features or general bug fixes. Critical security fixes continue until 12 months after Angular CLI’s Web Test Runner support is marked stable.

Pure Test is a free, minimal test runner for projects using JavaScript runtimes and browsers. It supports Node.js, Deno, Bun, Cloudflare Workers, and browsers, and its API includes test suites, assertions, lifecycle hooks, spies, fake timers, and retry and timeout options. The CLI provides multiple reporters, test filters, file watching, sharding, and fail-fast execution. For CI, `--shard` splits test files across jobs and exits cleanly when a shard has no files. TypeScript test discovery requires `--ts` on Node.js; it is automatic on Deno and Bun. A Deno adapter registers tests as `Deno.test()` calls for use with `deno test` and its filtering and IDE workflows. The README includes migration guides for Jest and Vitest and notes compatibility with common mock methods. Pure Test does not isolate tests, so lifecycle hooks are recommended for managing state. The project is beta, and its APIs may change. It is Apache-2.0 licensed, with no paid plans stated.