///

/// tip

If you want to call `async` functions in your tests apart from sending requests to your FastAPI application (e.g. asynchronous database functions), have a look at the [Async Tests](../advanced/async-tests.md){.internal-link target=_blank} in the advanced tutorial.

///

## Separating tests { #separating-tests }

## Servidores ASGI

Vamos nos aprofundar um pouco mais em detalhes.

FastAPI utiliza um padrão para construir frameworks e servidores web em Python chamado <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr>. FastAPI é um framework web ASGI.

            }

            return response;

        } catch (Exception e) {
            throw new IOException("Witness heartbeat RPC failed", e);
        }
    }

    /**
     * Requests asynchronous notifications from the witness service.
     *
     * @param contextHandle the context handle from registration
     * @return the async notify response containing notifications

 * ListenableFuture}</a>.
 *
 * <p>This class is GWT-compatible.
 *
 * <h3>Purpose</h3>
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, com.google.common.base.Function, Executor) Futures.transform}

   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new web socket and immediately returns it. Creating a web socket initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must either close or cancel the returned web socket when it is no longer
     * in use.
     */

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares { #adding-asgi-middlewares }

As **FastAPI** is based on Starlette and implements the <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr> specification, you can use any ASGI middleware.

A middleware doesn't have to be made for FastAPI or Starlette to work, as long as it follows the ASGI spec.

  }

  /**
   * An object that holds the final result of an asynchronous {@link ClosingFuture} operation and
   * allows the user to close all the closeable objects that were captured during it for later
   * closing.
   *
   * <p>The asynchronous operation will have completed before this object is created.
   *
   * @param <V> the type of the value of a successful operation

dökümantasyon için Pydantic gibi bir üçüncü parti kütüphane kullanmıyor, kendi içerisinde bunlara sahip. Yani bu veri tipi tanımlarını tekrar kullanmak pek de kolay değil.

Biraz daha detaylı ayarlamalara gerek duyuyor. Ayrıca <abbr title="ASGI (Asynchronous Server Gateway Interface): Asenkron Sunucu Ağ Geçidi Arabirimi, asenkron Python web uygulamaları geliştirmek için yeni standart.">ASGI</abbr> yerine <abbr title="WSGI (Web Server Gateway Interface): Web Sunucusu Ağ Geçidi Arabirimi, Pythonda senkron...

要讓 `await` 運作，它必須位於支持非同步功能的函式內。為此，只需使用 `async def` 宣告函式：

```Python hl_lines="1"
async def get_burgers(number: int):
    # Do some asynchronous stuff to create the burgers
    return burgers
```

...而不是 `def`:

```Python hl_lines="2"
# This is not asynchronous
def get_sequential_burgers(number: int):
    # Do some sequential stuff to create the burgers
    return burgers
```

///

### <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> { #starlette }

Starlette is a lightweight <abbr title="The new standard for building asynchronous Python web applications">ASGI</abbr> framework/toolkit, which is ideal for building high-performance asyncio services.

It is very simple and intuitive. It's designed to be easily extensible, and have modular components.