* Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits=15
 * Sec-WebSocket-Extensions: permessage-deflate; client_no_context_takeover
 * Sec-WebSocket-Extensions: permessage-deflate; server_max_window_bits="15"
 * Sec-WebSocket-Extensions: permessage-deflate; server_max_window_bits=15
 * Sec-WebSocket-Extensions: permessage-deflate; server_no_context_takeover
 * Sec-WebSocket-Extensions: permessage-deflate; server_no_context_takeover;

For this, you use the `TestClient` in a `with` statement, connecting to the WebSocket:

```Python hl_lines="27-31"
{!../../../docs_src/app_testing/tutorial002.py!}
```

!!! note

client = TestClient(app)


def test_get():
    response = client.get("/")
    assert response.text == html


def test_websocket_handle_disconnection():
    with client.websocket_connect("/ws/1234") as connection, client.websocket_connect(
        "/ws/5678"
    ) as connection_two:
        connection.send_text("Hello from 1234")
        data1 = connection.receive_text()

def test_websocket_with_header():
    client = TestClient(app)
    with pytest.raises(WebSocketDisconnect):
        with client.websocket_connect("/items/bar/ws?token=some-token") as websocket:
            message = "Message one"
            websocket.send_text(message)
            data = websocket.receive_text()
            assert data == "Session cookie or query token value is: some-token"
            data = websocket.receive_text()

        self.active_connections: list[WebSocket] = []

    async def connect(self, websocket: WebSocket):
        await websocket.accept()
        self.active_connections.append(websocket)

    def disconnect(self, websocket: WebSocket):
        self.active_connections.remove(websocket)

    async def send_personal_message(self, message: str, websocket: WebSocket):
        await websocket.send_text(message)

@needs_py39
def test_get(client: TestClient, html: str):
    response = client.get("/")
    assert response.text == html


@needs_py39
def test_websocket_handle_disconnection(client: TestClient):
    with client.websocket_connect("/ws/1234") as connection, client.websocket_connect(
        "/ws/5678"
    ) as connection_two:
        connection.send_text("Hello from 1234")
        data1 = connection.receive_text()

    client.dispatcher().executorService().shutdown();
  }

  @Override public void onOpen(WebSocket webSocket, Response response) {
    webSocket.send("Hello...");
    webSocket.send("...World!");
    webSocket.send(ByteString.decodeHex("deadbeef"));
    webSocket.close(1000, "Goodbye, World!");
  }

  @Override public void onMessage(WebSocket webSocket, String text) {
    System.out.println("MESSAGE: " + text);
  }

# WebSockets

Bei der Definition von WebSockets deklarieren Sie normalerweise einen Parameter vom Typ `WebSocket` und können damit Daten vom Client lesen und an ihn senden. Er wird direkt von Starlette bereitgestellt, Sie können ihn aber von `fastapi` importieren:

```python
from fastapi import WebSocket
```

!!! tip "Tipp"

   * messages.
   */
  open fun onOpen(
    webSocket: WebSocket,
    response: Response,
  ) {
  }

  /** Invoked when a text (type `0x1`) message has been received. */
  open fun onMessage(
    webSocket: WebSocket,
    text: String,
  ) {
  }

  /** Invoked when a binary (type `0x2`) message has been received. */
  open fun onMessage(
    webSocket: WebSocket,
    bytes: ByteString,
  ) {
  }

  /**

        self.body_params = body_params or []
        self.dependencies = dependencies or []
        self.security_requirements = security_schemes or []
        self.request_param_name = request_param_name
        self.websocket_param_name = websocket_param_name
        self.http_connection_param_name = http_connection_param_name
        self.response_param_name = response_param_name
        self.background_tasks_param_name = background_tasks_param_name