Django测试匹配查询不存在

如何解决Django测试匹配查询不存在

我是 Django 的新手。我正在构建一个应用，需要对用户对各种用途和功能的访问进行大量控制。

为此，我创建了一个名为“UserType”的模型，其中包含一些用户组作为对象，即扫描仪、守望者、枪手和管理员。

另一个模型，AssignedType，将用户分配给一个或多个 UserType。它有两个字段。 'user' 与 User 模型相关，'user_type' 与 UserType 模型相关。

控制访问权限的文件（rights.py）如下：

from .models import User,UserType,AssignedType 

# Get all user types in the database as model objects
scanner = UserType.objects.get(id=1)
overwatch = UserType.objects.get(id=2)
lancer = UserType.objects.get(id=3)
admin = UserType.objects.get(id=4)

# Rights of each type of user. Keys are the views and values are the user types allowed to access a particular view
group_rights = {
    'scanner':[scanner,admin],}

# Function to determine whether the logged user may access a view. Returns True if allowed. False otherwise.
def is_user_permitted(logged_user,view):
    
    # Get a list of users types assigned to the user
    assigned_types_objects = AssignedType.objects.all().filter(user=logged_user)
    assigned_types = []
    for assigned_type in assigned_types_objects:
        assigned_types.append(assigned_type.user_type)
    
    # Get a list of users types permitted to access the view.
    view_rights = group_rights[view]

    # Check whether there is any user type is common in the two lists. If so,user is authorized to access the view. 
    if set(assigned_types) & set(view_rights):
        return True
    else:
        return False

而调用上述文件中函数的视图如下：

@login_required
def scanner(request):
    if not is_user_permitted(request.user,'scanner'):
        raise PermissionDenied

    return render(request,"DataMech/scanner.html")

似乎一切正常。但是，当我尝试创建和运行测试时收到错误消息。以下是我的tests.py文件。

from django.test import TestCase,Client
from django.urls import reverse
from DataMech.models import User,AssignedType 

class TestScanner(TestCase):
    def setUp(self):
        User.objects.create(username='scanner1',password='abc')
        User.objects.create(username='scanner2',password='abc')
        User.objects.create(username='overwatch1',password='abc')
        User.objects.create(username='overwatch2',password='abc')
        User.objects.create(username='lancer1',password='abc')
        User.objects.create(username='lancer2',password='abc')
        User.objects.create(username='lancer3',password='abc')
        User.objects.create(username='lancer4',password='abc')
        User.objects.create(username='admin1',password='abc')
        UserType.objects.create(name='scanner')
        UserType.objects.create(name='overwatch')
        UserType.objects.create(name='lancer')
        UserType.objects.create(name='admin')
        AssignedType.objects.create(user='scanner1',user_type='scanner')
        AssignedType.objects.create(user='scanner2',user_type='scanner')
        AssignedType.objects.create(user='overwatch1',user_type='overwatch')
        AssignedType.objects.create(user='overwatch2',user_type='overwatch')
        AssignedType.objects.create(user='lancer1',user_type='lancer')
        AssignedType.objects.create(user='lancer2',user_type='lancer')
        AssignedType.objects.create(user='lancer3',user_type='lancer')
        AssignedType.objects.create(user='lancer4',user_type='lancer')
        AssignedType.objects.create(user='admin1',user_type='admin')

    def test_allow_access_only_if_user_is_authorized_GET(self):

        c = Client()
        c.login(username='scanner1',password='abc')
        response = c.get(reverse('scanner'))
        self.assertEquals(response.status_code,200)
        self.assertTemplateUsed(response,'DataMech/scanner.html')
        c.logout()

        c = Client()
        c.login(username='scanner2','DataMech/scanner.html')
        c.logout()

        c = Client()
        c.login(username='overwatch1',403)
        c.logout()

运行此测试会导致以下错误。

Traceback (most recent call last):
  File "C:\Users\Dell\Desktop\Financial reports project\FinData\FinData\manage.py",line 22,in <module>
    main()
  File "C:\Users\Dell\Desktop\Financial reports project\FinData\FinData\manage.py",line 18,in main
    execute_from_command_line(sys.argv)
  File "C:\Python39\lib\site-packages\django\core\management\__init__.py",line 401,in execute_from_command_line
    utility.execute()
  File "C:\Python39\lib\site-packages\django\core\management\__init__.py",line 395,in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python39\lib\site-packages\django\core\management\commands\test.py",line 23,in run_from_argv
    super().run_from_argv(argv)
  File "C:\Python39\lib\site-packages\django\core\management\base.py",line 330,in run_from_argv
    self.execute(*args,**cmd_options)
  File "C:\Python39\lib\site-packages\django\core\management\base.py",line 371,in execute
    output = self.handle(*args,**options)
  File "C:\Python39\lib\site-packages\django\core\management\commands\test.py",line 53,in handle
    failures = test_runner.run_tests(test_labels)
  File "C:\Python39\lib\site-packages\django\test\runner.py",line 698,in run_tests
    self.run_checks(databases)
  File "C:\Python39\lib\site-packages\django\test\runner.py",line 636,in run_checks
    call_command('check',verbosity=self.verbosity,databases=databases)
  File "C:\Python39\lib\site-packages\django\core\management\__init__.py",line 168,in call_command
    return command.execute(*args,**defaults)
  File "C:\Python39\lib\site-packages\django\core\management\base.py",**options)
  File "C:\Python39\lib\site-packages\django\core\management\commands\check.py",line 63,in handle
    self.check(
  File "C:\Python39\lib\site-packages\django\core\management\base.py",line 392,in check
    all_issues = checks.run_checks(
  File "C:\Python39\lib\site-packages\django\core\checks\registry.py",line 70,in run_checks
    new_errors = check(app_configs=app_configs,databases=databases)
  File "C:\Python39\lib\site-packages\django\core\checks\urls.py",line 13,in check_url_config
    return check_resolver(resolver)
  File "C:\Python39\lib\site-packages\django\core\checks\urls.py",in check_resolver
    return check_method()
  File "C:\Python39\lib\site-packages\django\urls\resolvers.py",line 408,in check
    for pattern in self.url_patterns:
  File "C:\Python39\lib\site-packages\django\utils\functional.py",line 48,in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "C:\Python39\lib\site-packages\django\urls\resolvers.py",line 589,in url_patterns
    patterns = getattr(self.urlconf_module,"urlpatterns",self.urlconf_module)
  File "C:\Python39\lib\site-packages\django\utils\functional.py",line 582,in urlconf_module
    return import_module(self.urlconf_name)
  File "C:\Python39\lib\importlib\__init__.py",line 127,in import_module
    return _bootstrap._gcd_import(name[level:],package,level)
  File "<frozen importlib._bootstrap>",line 1030,in _gcd_import
  File "<frozen importlib._bootstrap>",line 1007,in _find_and_load
  File "<frozen importlib._bootstrap>",line 986,in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>",line 680,in _load_unlocked
  File "<frozen importlib._bootstrap_external>",line 790,in exec_module
  File "<frozen importlib._bootstrap>",line 228,in _call_with_frames_removed
  File "C:\Users\Dell\Desktop\Financial reports project\FinData\FinData\FinData\urls.py",line 21,in <module>
    path("",include("DataMech.urls")),File "C:\Python39\lib\site-packages\django\urls\conf.py",line 34,in include
    urlconf_module = import_module(urlconf_module)
  File "C:\Python39\lib\importlib\__init__.py",in _call_with_frames_removed
  File "C:\Users\Dell\Desktop\Financial reports project\FinData\FinData\DataMech\urls.py",line 4,in <module>
    from . import views
  File "C:\Users\Dell\Desktop\Financial reports project\FinData\FinData\DataMech\views.py",line 12,in <module>
    from .rights import is_user_permitted
  File "C:\Users\Dell\Desktop\Financial reports project\FinData\FinData\DataMech\rights.py",in <module>
    scanner = UserType.objects.get(id=1)
  File "C:\Python39\lib\site-packages\django\db\models\manager.py",line 85,in manager_method
    return getattr(self.get_queryset(),name)(*args,**kwargs)
  File "C:\Python39\lib\site-packages\django\db\models\query.py",line 429,in get
    raise self.model.DoesNotExist(
DataMech.models.DoesNotExist: UserType matching query does not exist.

我在这里做错了什么？

解决方法

在您的视图中导入 rights.py 文件。当您的测试开始时，没有创建 UserType 实例。当 Django 尝试设置以便它可以启动您的测试时，由于这个事实，它会收到此错误。您应该改用 get_or_create 方法来确保创建对象：

scanner,created = UserType.objects.get_or_create(name='scanner')

等等。您还应该为此调整您的测试，不要在那里创建对象或使用此方法。