For most users, Cloudflare recommends using the Workers Vitest integration for unit testing Workers and Pages Functions projects. Vitest ↗ is a popular JavaScript testing framework featuring a fast watch mode, Jest compatibility, and default TypeScript support. Cloudflare provides the @cloudflare/vitest-plugin Vite plugin, which runs your Vitest tests inside the Workers runtime.
The Workers Vitest integration:
- Supports both unit tests and integration tests.
- Provides direct access to Workers runtime APIs and bindings.
- Implements isolated per-test-file storage.
- Runs tests fully-locally using Miniflare ↗.
- Leverages Vitest's hot-module reloading for near instant reruns.
- Supports projects with multiple Workers.
Write your first test
If you use @cloudflare/vitest-pool-workers, refer to Migrate to Vitest plugin.