pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"
            )  # pragma: no cover


@needs_py310
def test_websocket_invalid_data(app: FastAPI):
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/items/foo/ws?q=bar&token=some-token"):
            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"

    * You wouldn't write an application in Uvicorn directly. That would mean that your code would have to include more or less, at least, all the code provided by Starlette (or **FastAPI**). And if you did that, your final application would have the same overhead as having used a framework and minimizing your app code and bugs.
    * If you are comparing Uvicorn, compare it against Daphne, Hypercorn, uWSGI, etc. Application servers.

            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"
            )  # pragma: no cover


@needs_py39
def test_websocket_invalid_data(app: FastAPI):
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/items/foo/ws?q=bar&token=some-token"):
            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"

@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,
        content={"message": f"Oops! {exc.name} did something. There goes a rainbow..."},
    )


@app.get("/unicorns/{name}")
async def read_unicorn(name: str):
    if name == "yolo":
        raise UnicornException(name=name)

```

请求 `/unicorns/yolo` 时，路径操作会触发 `UnicornException`。

但该异常将会被 `unicorn_exception_handler` 处理。

接收到的错误信息清晰明了，HTTP 状态码为 `418`，JSON 内容如下：

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}

```

!!! note "技术细节"

    `from starlette.requests import Request` 和 `from starlette.responses import JSONResponse` 也可以用于导入 `Request` 和 `JSONResponse`。

```

📥, 🚥 👆 📨 `/unicorns/yolo`, *➡ 🛠️* 🔜 `raise` `UnicornException`.

✋️ ⚫️ 🔜 🍵 `unicorn_exception_handler`.

, 👆 🔜 📨 🧹 ❌, ⏮️ 🇺🇸🔍 👔 📟 `418` & 🎻 🎚:

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

!!! note "📡 ℹ"
    👆 💪 ⚙️ `from starlette.requests import Request` & `from starlette.responses import JSONResponse`.

            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"
            )  # pragma: no cover


def test_websocket_invalid_data():
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/items/foo/ws?q=bar&token=some-token"):
            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"

            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"
            )  # pragma: no cover


def test_websocket_invalid_data():
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/items/foo/ws?q=bar&token=some-token"):
            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"

            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"
            )  # pragma: no cover


@needs_py310
def test_websocket_invalid_data(app: FastAPI):
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/items/foo/ws?q=bar&token=some-token"):
            pytest.fail(
                "did not raise WebSocketDisconnect on __enter__"

ここで、`/unicorns/yolo`をリクエストすると、*path operation*は`UnicornException`を`raise`します。

しかし、これは`unicorn_exception_handler`で処理されます。

そのため、HTTPステータスコードが`418`で、JSONの内容が以下のような明確なエラーを受け取ることになります:

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

!!! note "技術詳細"
    また、`from starlette.requests import Request`と`from starlette.responses import JSONResponse`を使用することもできます。