Django channel 2，在测试中访问数据库

Question

我最近将我的项目更新为 Django 2 和 channel 2。现在我正在尝试重写我的聊天应用程序测试。

我面临依赖于 pytest-django 的 django db 标记的测试问题。我尝试在 fixture 、设置方法、测试函数本身中创建对象，在 WebsocketCommunicator 上使用 async_to_sync .然而，这些都没有奏效。

如果我在 fixture 中创建一个用户并正确保存它会得到一个 id。但是，在我的消费者 Django 中，在数据库中看不到该用户。并将其视为匿名用户。

我有一个临时 token ，用于在 websocket.connect 上对用户进行身份验证。

@pytest.fixture
def room():
    room = generate_room()
    room.save()
    return room


@pytest.fixture
def room_with_user(room, normal_user):
    room.users.add(normal_user)
    yield room
    room.users.remove(normal_user)

@pytest.fixture
def normal_user():
    user = generate_user()
    user.save()
    return user

@pytest.mark.django_db
class TestConnect:

    @pytest.mark.asyncio
    async def test_get_connected_client(self, path, room_with_user, temp_token):
        assert get_path(room_with_user.id) == path

        communicator = QSWebsocketCommunicator(application, path, query_string=get_query_string(temp_token))
        connected, subprotocol = await communicator.connect()
        assert connected
        await communicator.disconnect()

消费者:

class ChatConsumer(JsonWebsocketConsumer):
    def connect(self):
        # Called on connection. Either call

        self.user = self.scope['user']

        self.room_id = self.scope['url_route']['kwargs']['room_id']
        group = f'room_{self.room_id}'
        users = list(User.objects.all())  # no users here
        self.group_name = group

        if not (self.user is not None and self.user.is_authenticated):
            return self.close({'Error': 'Not authenticated user'})

        try:
            self.room = Room.objects.get(id=self.room_id, users__id=self.user.id)
        except ObjectDoesNotExist:
            return self.close({'Error': 'Room does not exists'})

        # Send success response
        self.accept()

        # Save user as active
        self.room.active_users.add(self.user)

我的认证中间件

class OAuthTokenAuthMiddleware:
    """
    Custom middleware that takes Authorization header and read OAuth token from it.
    """

    def __init__(self, inner):
        # Store the ASGI application we were passed
        self.inner = inner

    def __call__(self, scope):
        temp_token = self.get_token(scope)
        scope['user'] = self.validate_token(temp_token)
        return self.inner(scope)

    @staticmethod
    def get_token(scope) -> str:
        return url_parse.parse_qs(scope['query_string'])[b'token'][0].decode("utf-8")

    @staticmethod
    def validate_token(token):
        try:
            token = TemporaryToken.objects.select_related('user').get(token=token)
            if token.is_active():
                token.delete()
                return token.user
            else:
                return AnonymousUser()
        except ObjectDoesNotExist:
            return AnonymousUser()

以及接受 query_string 以包含我的一次性 token 的自定义 WebsocketCommunicator

class QSWebsocketCommunicator(WebsocketCommunicator):
    def __init__(self, application, path, headers=None, subprotocols=None,
                 query_string: Optional[Union[str, bytes]]=None):
        if isinstance(query_string, str):
            query_string = str.encode(query_string)
        self.scope = {
            "type": "websocket",
            "path": path,
            "headers": headers or [],
            "subprotocols": subprotocols or [],
            "query_string": query_string or ''
        }
        ApplicationCommunicator.__init__(self, application, self.scope)

我的问题是如何在测试/装置中创建用户、房间等对象，以便我可以在 Django 消费者中访问它们。

或者你有其他想法我怎样才能克服这个？

Answer 1

使用您提供的代码几乎不可能重现您的问题。阅读 How to create a Minimal, Complete, and Verifiable example .但是，我认为您应该在测试中使用真实交易作为普通 pytest.mark.django_db将跳过事务并且不会在数据库中存储任何数据本身。一个工作示例:

# routing.py

from django import http
from django.conf.urls import url
from django.contrib.auth.models import User
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.generic.websocket import JsonWebsocketConsumer

class ChatConsumer(JsonWebsocketConsumer):
    def connect(self):
        self.user = self.scope['user']
        print('user in scope, set by middleware:', self.user)
        users = list(User.objects.all())  # no users here
        print('all users in chat consumer:', users)

        if not (self.user is not None and self.user.is_authenticated):
            return self.close({'Error': 'Not authenticated user'})

        # Send success response
        self.accept()


class OAuthTokenAuthMiddleware:
    def __init__(self, inner):
        # Store the ASGI application we were passed
        self.inner = inner

    def __call__(self, scope):
        token = self.get_token(scope)
        print('token in middleware:', token)
        scope['user'] = User.objects.get(username=token)
        return self.inner(scope)

    @staticmethod
    def get_token(scope) -> str:
        d = http.QueryDict(scope['query_string'])
        return d['token']


APP = ProtocolTypeRouter({
    'websocket': OAuthTokenAuthMiddleware(URLRouter([url(r'^websocket/$', ChatConsumer)])),
})

创建用户名 spam 的示例 fixture :

@pytest.fixture(scope='function', autouse=True)
def create_user():
    with transaction.atomic():
        User.objects.all().delete()
        user = User.objects.create_user(
            'spam', 'spam@example.com', password='eggs',
            first_name='foo', last_name='bar'
        )
    return user

现在，我将测试标记为事务性测试，这意味着每个查询实际上都已提交。现在测试用户被存储到数据库中，并且在中间件/消费者中进行的查询实际上可以返回一些有意义的东西:

@pytest.mark.django_db(transaction=True)
@pytest.mark.asyncio
async def test_get_connected_client():
    app = OAuthTokenAuthMiddleware(URLRouter([url(r'^websocket/$', ChatConsumer)]))
    communicator = QSWebsocketCommunicator(app, '/websocket/', query_string='token=spam')
    connected, subprotocol = await communicator.connect()
    assert connected
    await communicator.disconnect()

运行测试测试会产生所需的结果:

$ pytest -vs
================================== test session starts =================================
platform darwin -- Python 3.6.3, pytest-3.4.0, py-1.5.2, pluggy-0.6.0 -- /Users/hoefling/.virtualenvs/stackoverflow/bin/python
cachedir: .pytest_cache
Django settings: spam.settings (from environment variable)
rootdir: /Users/hoefling/projects/private/stackoverflow/so-49136564/spam, inifile: pytest.ini
plugins: celery-4.1.0, forked-0.2, django-3.1.2, cov-2.5.1, asyncio-0.8.0, xdist-1.22.0, mock-1.6.3, hypothesis-3.44.4
collected 1 item

tests/test_middleware.py::test_get_connected_client Creating test database for alias 'default'...
token in middleware: spam
user in scope: spam
all users in chat consumer: [<User: spam>]
PASSEDDestroying test database for alias 'default'...


=============================== 1 passed in 0.38 seconds ================================

顺便说一句，你不需要绕过 WebsocketCommunicator不再，因为它现在能够处理查询字符串，请参阅 this issue closed .