#### Asynchronicity

We love modern JavaScript, especially its emphasis on **asynchronous** data handling. That’s why Nest fully supports `async` functions. Every `async` function must return a `Promise`, which allows you to return a deferred value that Nest can resolve automatically. Here's an example:

```typescript

@@filename(cats.controller)

@Get()

async findAll(): Promise<any[]> {

return [];

}

@@switch

@Get()

async findAll() {

return [];

}

```