Testing

The Workers platform has a variety of ways to test your applications, depending on your requirements. We recommend using the Vitest integration, which allows for unit testing individual functions within workerd ↗. However, if you don't use Vitest, both Miniflare's API and the unstable_startWorker() API provide options for testing your Worker in any testing framework.

Write your first test

Testing comparison matrix

Feature	Vitest integration	unstable_startWorker()	Miniflare's API
Unit testing	✅	❌	❌
Integration testing	✅	✅	✅
Loading Wrangler configuration files	✅	✅	❌
Use bindings directly in tests	✅	❌	✅
Isolated per-test storage	✅	❌	❌
Outbound request mocking	✅	❌	✅
Multiple Worker support	✅	✅	✅
Direct access to Durable Objects	✅	❌	❌
Run Durable Object alarms immediately	✅	❌	❌
List Durable Objects	✅	❌	❌
Testing service Workers	❌	✅	✅

Pages Functions

The content described on this page is also applicable to Pages Functions. Pages Functions are Cloudflare Workers and can be thought of synonymously with Workers in this context.