Django模型字段驗證器不會引發Exception

Question

我在models.py有以下模型：

@python_2_unicode_compatible
class Session(ModelCommon): # ModelCommon is an abstract Model which extends from models.Model with the fields name(CharField) and enabled(BooleanField).
    """
    Model Session with foreign key to Model Event.
    """
    event = models.ForeignKey(verbose_name=_('Event'), to=Event, default=None, null=False, blank=False)
    start_datetime = models.DateTimeField(verbose_name=_('Session Starts'), default=None, null=False, blank=False)
    end_datetime = models.DateTimeField(verbose_name=_('Session Ends'), default=None, null=False, blank=False)
    available = models.BooleanField(verbose_name=_('Available'), default=True, null=False, blank=False)
    price = models.DecimalField(verbose_name=_('Price'), max_digits=10, decimal_places=2,
                                validators=[MinValueValidator(0.00)],
                                default=None, null=False, blank=False)

當我測試我的模型時，如果price是負數，它不應該保存在數據庫中，它不會引發異常。

test_models.py ：

class SessionTestCase(TestCase):
    """
    Case of tests for Model Session.
    """

    def setUpTestData(cls):
        """
        This method is used to declare dummy data that could be used by all tests.
        """
        cls.test_event = Event(name='Test Event Name for Session', enabled=True)
        cls.test_event.save()

    def setUp(self):
        """
        This method is used to run code before each test.
        """
        self.session = Session(event=self.test_event, name='Session No1', enabled=True,
                               start_datetime=timezone.now() + timedelta(days=1),
                               end_datetime=timezone.now() + timedelta(days=3), price=0)


    def test_session_price_cannot_be_negative(self):
        """
        :return: Passed if Session object with negative price raises Exception.
        """
        self.session.price = -20.0
        self.assertRaises(Exception, lambda: self.session.save())

最后，當我運行我的test_models.py ，我收到以下消息：

Failure
Traceback (most recent call last):
    self.assertRaises(Exception, lambda: self.session.save())
AssertionError: Exception not raised

Answer 1

調用save()不會觸發驗證。 有關更多信息，請參閱有關驗證對象的Django文檔。 你可以改為調用full_clean 。

self.session.price = -20.0
self.assertRaises(Exception, lambda: self.session.full_clean())

請注意，您可以從代碼中刪除lambda並傳遞callable。 捕獲更具體的ValidationError而不是Exception也會更好。

self.session.price = -20.0
self.assertRaises(ValidationError, self.session.full_clean)