Jest vs Pure Test

Jest is a free, self-hosted JavaScript testing framework focused on checking correctness. It supports projects using Babel, TypeScript, Node, React, Angular, Vue and other technologies, and aims to run without configuration on most JavaScript projects. Snapshot tests compare rendered output with a saved reference. Tests run in separate processes for parallel execution, while the --coverage flag can collect coverage, including from files without tests. Mock functions and a custom import resolver support replacing objects and observing calls. Interactive watch mode reruns tests related to changed files. Installation guidance covers npm, Yarn, pnpm and Bun. Documentation describes webpack and Parcel use, but states that Vite is unsupported because of plugin-system incompatibilities. With Babel handling TypeScript, Jest transpiles tests without type-checking them during execution. A free plan is listed at free, with no paid plans or usage limits stated.

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.