Disconnect() method of WebSocketConsumer not being called

I have the following MyConsumer class:

from channels.generic.websocket import WebsocketConsumer
from channels.exceptions import StopConsumer
import json

class MyConsumer(WebsocketConsumer):
   
       def connect(self):
          self.accept()
       
       def receive(self, text_data=None, bytes_data=None):
          data = json.loads(text_data)
          n = data["number"]
          
          for i in range(n):
              self.send(json.dumps({"number":i}))
              
       def disconnect(self, code):
           raise StopConsumer()

The input JSON contains only a single parameter called number. I am testing this code using a chrome plugin. When I open the connection and close it without sending any message, the disconnect method is executed as expected.

When the number is for example 100000 and the loop inside the receive method is not yet finished and I disconnect in between, the disconnect method is not called and I get the following error:

ERROR - server - Exception inside application: Attempt to send on a closed protocol.
File "MyConsumer.py", line 2, in receive
    self.send
File "python3.6/site-packages/channels/generic/websocket.py", line 69, in send
    {"type": "websocket.send", "text": text_data},
  File "python3.6/site-packages/channels/consumer.py", line 107, in send
    self.base_send(message)
  File "python3.6/site-packages/asgiref/sync.py", line 64, in __call__
    return call_result.result()
  File "/usr/local/var/pyenv/versions/3.6.10/lib/python3.6/concurrent/futures/_base.py", line 432, in result
    return self.__get_result()
  File "/usr/local/var/pyenv/versions/3.6.10/lib/python3.6/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "python3.6/site-packages/asgiref/sync.py", line 78, in main_wrap
    result = await self.awaitable(*args, **kwargs)
  File "python3.6/site-packages/channels/sessions.py", line 220, in send
    return await self.real_send(message)
  File "python3.6/site-packages/daphne/server.py", line 198, in handle_reply
    protocol.handle_reply(message)
  File "python3.6/site-packages/daphne/ws_protocol.py", line 179, in handle_reply
    self.serverSend(message["text"], False)
  File "site-packages/daphne/ws_protocol.py", line 223, in serverSend
    self.sendMessage(content.encode("utf8"), binary)
  File "python3.6/site-packages/autobahn/websocket/protocol.py", line 2216, in sendMessage
    raise Disconnected("Attempt to send on a closed protocol")
  Attempt to send on a closed protocol

OS: Mac OS X
runtime: python 3.6.10
daphne==2.2.0
Django==2.0.6
channels==2.1.1
channels-redis==2.2.1

• Expected: The docs mention that the disconnect method should be called when the client closes the connection and an event is received (https://channels.readthedocs.io/en/latest/topics/consumers.html#closing-consumers). I expect that the disconnect method is called even if the loop is not finished yet.

• I am running Channels using daphne.

[carltongibson]

A failing test demonstrating the issue, and then the fix, would be appreciated here.

[brubbel]

Same issue for AsyncWebsocketConsumer.

Issue caused by a recent change in autobahn: https://autobahn.readthedocs.io/en/latest/changelog.html#id17

fix: WebSocket protocol instances now raise autobahn.exception.Disconnected when sending on a closed connection (#1002) https://github.com/crossbario/autobahn-python/issues/1002

Possible solution by subclassing AsyncWebsocketConsumer (channels/generic/websocket.py):

    async def send(self, *args, **kwargs):
        try:
            await super().send(*args, **kwargs)
        except autobahn.exception.Disconnected:
            await self.close()