fix(websocket): ASGI websocket must pass thru bytes as is (#2651)

sanic/server/websockets/connection.py

@@ -45,15 +45,15 @@ async def send(self, data: Union[str, bytes], *args, **kwargs) -> None:
 
         await self._send(message)
 
-    async def recv(self, *args, **kwargs) -> Optional[str]:
+    async def recv(self, *args, **kwargs) -> Optional[Union[str, bytes]]:
         message = await self._receive()
 
         if message["type"] == "websocket.receive":
             try:
                 return message["text"]
             except KeyError:
                 try:
-                    return message["bytes"].decode()
+                    return message["bytes"]
                 except KeyError:
                     raise InvalidUsage("Bad ASGI message received")
         elif message["type"] == "websocket.disconnect":

tests/test_asgi.py

@@ -342,7 +342,7 @@ async def test_websocket_send(send, receive, message_stack):
 
 
 @pytest.mark.asyncio
-async def test_websocket_receive(send, receive, message_stack):
+async def test_websocket_text_receive(send, receive, message_stack):
     msg = {"text": "hello", "type": "websocket.receive"}
     message_stack.append(msg)
 
@@ -351,6 +351,15 @@ async def test_websocket_receive(send, receive, message_stack):
 
     assert text == msg["text"]
 
+@pytest.mark.asyncio
+async def test_websocket_bytes_receive(send, receive, message_stack):
+    msg = {"bytes": b"hello", "type": "websocket.receive"}
+    message_stack.append(msg)
+
+    ws = WebSocketConnection(send, receive)
+    data = await ws.receive()
+
+    assert data == msg["bytes"]
 
 @pytest.mark.asyncio
 async def test_websocket_accept_with_no_subprotocols(