[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Worker](https://evolu.dev/docs/api-reference/common/Worker) › testCreateWorker

```ts
function testCreateWorker<Input, Output>(): TestWorker<Input, Output>;
```

Defined in: [packages/common/src/Worker.ts:334](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Worker.ts#L334)

Creates a connected [TestWorker](https://evolu.dev/docs/api-reference/common/Worker/interfaces/TestWorker) for testing.

The returned worker includes its typed [TestWorker.self](https://evolu.dev/docs/api-reference/common/Worker/interfaces/TestWorker#self) counterpart, so
tests can exercise dedicated worker communication without a real thread.