{!../../docs_src/app_testing/tutorial001.py!}
```

/// tip

Notice that the testing functions are normal `def`, not `async def`.

And the calls to the client are also normal calls, not using `await`.

This allows you to use `pytest` directly without complications.

///

/// note | "Technical Details"

You could also use `from starlette.testclient import TestClient`.

    peer.acceptFrame() // RST_STREAM
    peer.acceptFrame() // DEGRADED PING
    peer.acceptFrame() // AWAIT PING
    peer.sendFrame().ping(true, Http2Connection.DEGRADED_PING, 1) // DEGRADED PONG
    peer.sendFrame().ping(true, Http2Connection.AWAIT_PING, 0) // AWAIT PONG
    peer.play()

    // Play it back.
    val connection = connect(peer)

In diesem Fall schreibt die Taskfunktion in eine Datei (den Versand einer E-Mail simulierend).

Und da der Schreibvorgang nicht `async` und `await` verwendet, definieren wir die Funktion mit normalem `def`:

```Python hl_lines="6-9"
{!../../docs_src/background_tasks/tutorial001.py!}
```

## Den Hintergrundtask hinzufügen

            super.process(consumer);
            latch.countDown();
        }

        @Override
        public void waitForProcessed() throws InterruptedException {
            latch.await();
        }
    }

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>⚖️ ⚙️ <code>async def</code>...</summary>

🚥 👆 📟 ⚙️ `async` / `await`, ⚙️ `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>או השתמשו ב - <code>async def</code>...</summary>

אם הקוד שלכם משתמש ב - `async` / `await`, השתמשו ב - `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():

Nesse caso, a função de tarefa gravará em um arquivo (simulando o envio de um e-mail).

E como a operação de gravação não usa `async` e `await`, definimos a função com `def` normal:

```Python hl_lines="6-9"
{!../../docs_src/background_tasks/tutorial001.py!}
```

## Adicionar a tarefa em segundo plano

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Add the background task

      // We wait at most 1 second, so we don't ever turn multiple lost threads into
      // a test timeout failure.
      val waitTime = (entryTime + 1_000_000_000L - System.nanoTime())
      if (!queue.idleLatch().await(waitTime, TimeUnit.NANOSECONDS)) {
        TaskRunner.INSTANCE.lock.withLock {
          TaskRunner.INSTANCE.cancelAll()
        }
        fail<Unit>("Queue still active after 1000 ms")
      }
    }
  }

            // that the stream has since been closed (such as if this write timed out.)
            if (!streams.containsKey(streamId)) {
              throw IOException("stream closed")
            }
            condition.await() // Wait until we receive a WINDOW_UPDATE.
          }
        } catch (e: InterruptedException) {
          Thread.currentThread().interrupt() // Retain interrupted status.
          throw InterruptedIOException()