Django async testing: Cannot operate on a closed database

Question

I was following this tutorial on testdriven.io in order to test some async functions in django and I need to add som decorators in order to enable my async tests to access to the DB. However, I get the following error message:

Error
Traceback (most recent call last):
  File "/Users/apple/.local/share/virtualenvs/backend-KucV-wUh/lib/python3.9/site-packages/django/db/backends/base/base.py", line 237, in _cursor
    return self._prepare_cursor(self.create_cursor(name))
  File "/Users/apple/.local/share/virtualenvs/backend-KucV-wUh/lib/python3.9/site-packages/django/db/backends/sqlite3/base.py", line 274, in create_cursor
    return self.connection.cursor(factory=SQLiteCursorWrapper)
sqlite3.ProgrammingError: Cannot operate on a closed database.

---

@database_sync_to_async
def create_user():
    user = User.objects.create(
        username='username',
    )
    user.set_password('password')
    user.save()




@pytest.mark.asyncio
@pytest.mark.django_db(transaction=True)
class WebsocketTests(TestCase):

    async def test_not_authenticated(self):
        await create_user()
        ..... other async functions

Answer 1

1. make sure to `pip install pytest pytest-django pytest-asyncio
2. use @pytest.mark.asyncio and @pytest.mark.django_db(transaction=True)

from asgiref.sync import sync_to_async
from channels.db import database_sync_to_async


@database_sync_to_async
def MakeMessage():
    Message.objects.create()

@pytest.mark.asyncio
@pytest.mark.django_db(transaction=True)
class TestWebSocket:

    async def test_connection(self, settings):
          communicator = WebsocketCommunicator( application=application, path=path )
          connected, _ = await communicator.connect()
          assert connected
         m = await sync_to_async(Message.objects.count)()
         assert m == 0
         await MakeMessage()
         m = await sync_to_async(Message.objects.count)()
         assert m == 1

#settings.py
WSGI_APPLICATION = 'frosty_breeze_25125.wsgi.application'
ASGI_APPLICATION = 'frosty_breeze_25125.asgi.application'

host = os.environ.get('REDIS_URL', 'redis://localhost:6379') if IS_DEPLOYED else ('0.0.0.0', 6379)
CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer',
        'CONFIG': {
            "hosts": [host],
        },
    },
}

REDIS_URL = [host]