channels-bug-connection-closed

Minimal repro for Channels bug #1091.

To setup:

$ python -m venv venv
$ source venv/bin/activate
$ pip install channels daphne django

Then run with:

$ ./manage.py test
...
======================================================================
ERROR: test_websocket (example.tests.ExampleConsumerTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/.../python3.10/site-packages/django/db/backends/base/base.py", line 301, in _cursor
    return self._prepare_cursor(self.create_cursor(name))
  File "/.../python3.10/site-packages/django/db/backends/sqlite3/base.py", line 177, in create_cursor
    return self.connection.cursor(factory=SQLiteCursorWrapper)
sqlite3.ProgrammingError: Cannot operate on a closed database.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/.../python3.10/site-packages/asgiref/sync.py", line 218, in __call__
    return call_result.result()
  File "/Users/chainz/.pyenv/versions/3.10.8/lib/python3.10/concurrent/futures/_base.py", line 451, in result
    return self.__get_result()
  File "/Users/chainz/.pyenv/versions/3.10.8/lib/python3.10/concurrent/futures/_base.py", line 403, in __get_result
    raise self._exception
  File "/.../python3.10/site-packages/asgiref/sync.py", line 284, in main_wrap
    result = await self.awaitable(*args, **kwargs)
  File "/Users/chainz/tmp/channelstest/example/tests.py", line 10, in test_websocket
    connected, subprotocol = await communicator.connect()
  File "/.../python3.10/site-packages/channels/testing/websocket.py", line 36, in connect
    response = await self.receive_output(timeout)
  File "/.../python3.10/site-packages/asgiref/testing.py", line 79, in receive_output
    self.future.result()
  File "/.../python3.10/site-packages/channels/consumer.py", line 94, in app
    return await consumer(scope, receive, send)
  File "/.../python3.10/site-packages/channels/consumer.py", line 62, in __call__
    await await_many_dispatch([receive], self.dispatch)
  File "/.../python3.10/site-packages/channels/utils.py", line 50, in await_many_dispatch
    await dispatch(result)
  File "/.../python3.10/site-packages/channels/consumer.py", line 73, in dispatch
    await handler(message)
  File "/.../python3.10/site-packages/channels/generic/websocket.py", line 173, in websocket_connect
    await self.connect()
  File "/Users/chainz/tmp/channelstest/example/consumers.py", line 8, in connect
    await basic_query()
  File "/.../python3.10/site-packages/asgiref/sync.py", line 435, in __call__
    ret = await asyncio.wait_for(future, timeout=None)
  File "/Users/chainz/.pyenv/versions/3.10.8/lib/python3.10/asyncio/tasks.py", line 408, in wait_for
    return await fut
  File "/.../python3.10/site-packages/asgiref/current_thread_executor.py", line 22, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/.../python3.10/site-packages/channels/db.py", line 13, in thread_handler
    return super().thread_handler(loop, *args, **kwargs)
  File "/.../python3.10/site-packages/asgiref/sync.py", line 476, in thread_handler
    return func(*args, **kwargs)
  File "/Users/chainz/tmp/channelstest/example/consumers.py", line 14, in basic_query
    with connection.cursor() as cursor:
  File "/.../python3.10/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/.../python3.10/site-packages/django/db/backends/base/base.py", line 323, in cursor
    return self._cursor()
  File "/.../python3.10/site-packages/django/db/backends/base/base.py", line 300, in _cursor
    with self.wrap_database_errors:
  File "/.../python3.10/site-packages/django/db/utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/.../python3.10/site-packages/django/db/backends/base/base.py", line 301, in _cursor
    return self._prepare_cursor(self.create_cursor(name))
  File "/.../python3.10/site-packages/django/db/backends/sqlite3/base.py", line 177, in create_cursor
    return self.connection.cursor(factory=SQLiteCursorWrapper)
django.db.utils.ProgrammingError: Cannot operate on a closed database.