consumer subscriptions, fix serializer bug

scripts/test_ws_client.py

@@ -4,22 +4,31 @@ import socket
 
 import websockets
 
+from freqtrade.enums import RPCMessageType
+from freqtrade.rpc.api_server.ws.channel import WebSocketChannel
+
 
 logging.basicConfig(level=logging.DEBUG)
 logger = logging.getLogger(__name__)
 
 
 async def _client():
+    subscribe_topics = [RPCMessageType.WHITELIST]
     try:
         while True:
             try:
                 url = "ws://localhost:8080/api/v1/message/ws?token=testtoken"
                 async with websockets.connect(url) as ws:
+                    channel = WebSocketChannel(ws)
+
                     logger.info("Connection successful")
+                    # Tell the producer we only want these topics
+                    await channel.send(subscribe_topics)
+
                     while True:
                         try:
                             data = await asyncio.wait_for(
-                                ws.recv(),
+                                channel.recv(),
                                 timeout=5
                             )
                             logger.info(f"Data received - {data}")
@@ -27,14 +36,14 @@ async def _client():
                             # We haven't received data yet. Check the connection and continue.
                             try:
                                 # ping
-                                ping = await ws.ping()
+                                ping = await channel.ping()
                                 await asyncio.wait_for(ping, timeout=2)
                                 logger.debug(f"Connection to {url} still alive...")
                                 continue
                             except Exception:
                                 logger.info(
                                     f"Ping error {url} - retrying in 5s")
-                                asyncio.sleep(2)
+                                await asyncio.sleep(2)
                                 break
 
             except (socket.gaierror, ConnectionRefusedError):