# Testing Events: startup - shutdown

When you need your event handlers (`startup` and `shutdown`) to run in your tests, you can use the `TestClient` with a `with` statement:

```Python hl_lines="9-12  20-24"
{!../../../docs_src/app_testing/tutorial003.py!}

# 测试事件：启动 - 关闭

使用 `TestClient` 和 `with` 语句，在测试中运行事件处理器（`startup` 与 `shutdown`）。

```Python hl_lines="9-12  20-24"
{!../../../docs_src/app_testing/tutorial003.py!}

from fastapi import FastAPI

app = FastAPI()


@app.on_event("shutdown")
def shutdown_event():
    with open("log.txt", mode="a") as log:
        log.write("Application shutdown")


@app.get("/items/")
async def read_items():

### `shutdown`-Event

Um eine Funktion hinzuzufügen, die beim Herunterfahren der Anwendung ausgeführt werden soll, deklarieren Sie sie mit dem Event `shutdown`:

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

Hier schreibt die `shutdown`-Eventhandler-Funktion eine Textzeile `"Application shutdown"` in eine Datei `log.txt`.

!!! info

### Evento `shutdown`

Para adicionar uma função que deve ser executada quando a aplicação estiver encerrando, declare ela com o evento `"shutdown"`:

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

Aqui, a função de manipulação de evento `shutdown` irá escrever uma linha de texto `"Application shutdown"` no arquivo `log.txt`.

!!! info "Informação"

* Hỗ trợ **WebSocket**.
* In-process background tasks.
* Startup and shutdown events.
* Client cho kiểm thử xây dựng trên HTTPX.
* **CORS**, GZip, Static Files, Streaming responses.
* Hỗ trợ **Session and Cookie**.
* 100% test coverage.
* 100% type annotated codebase.

        response = client.get("/items/")
        assert response.status_code == 200, response.text
        assert response.json() == [{"name": "Foo"}]
    with open("log.txt") as log:
        assert "Application shutdown" in log.read()


def test_openapi_schema(app: FastAPI):
    with TestClient(app) as client:
        response = client.get("/openapi.json")
        assert response.status_code == 200, response.text

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

It has:

* Seriously impressive performance.
* WebSocket support.
* In-process background tasks.
* Startup and shutdown events.
* Test client built on HTTPX.
* CORS, GZip, Static Files, Streaming responses.
* Session and Cookie support.
* 100% test coverage.
* 100% type annotated codebase.
* Few hard dependencies.

        data = websocket.receive_text()
        assert data == "a_query_param"


def test_wrong_uri():
    """
    Verify that a websocket connection to a non-existent endpoing returns in a shutdown
    """
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect) as e:
        with client.websocket_connect("/no-router/"):
            pass  # pragma: no cover

        state.app_startup = True

    @app.on_event("shutdown")
    def app_shutdown() -> None:
        state.app_shutdown = True

    router = APIRouter()

    @router.on_event("startup")
    def router_startup() -> None:
        state.router_startup = True

    @router.on_event("shutdown")
    def router_shutdown() -> None:
        state.router_shutdown = True

    sub_router = APIRouter()