I'm creating a number of tests for a Django app whilst using factory-boy
to generate the model instances. However, I have tests thats failing but I'm not entirely sure why this is the case.
def test__str__(self) -> None:
self.assertEqual(
str(self.academy_settings),
"Academy settings for {}".format(self.academy_settings.academy),
)
As you can see I'm verifying a __str__
method on one of our django models, but when I run this test I get the following error.
Failure
Expected :"<AcademySettingsFactory for <class 'core.models.AcademySettings'>>"
Actual :'Academy settings for <factory.declarations.SubFactory object at 0x1105ce438>'
These errors are somewhat puzzling to me. Its clear that the actual result is nothing like the result that I am expecting, but the same could be set for the expected result.
As you can see in the model definitions below both of them should return simple string objects.
class Academy(models.Model):
name = models.CharField(
max_length=400, unique=True
)
def __str__(self) -> str:
return "{}".format(self.name)
class AcademySettings(models.Model):
academy = models.ForeignKey(Academy, on_delete=models.CASCADE)
(...)
def __str__(self) -> str:
return "Academy settings for {}".format(self.academy)
Now, as you can see in the factories below I've written some custom lazy_attribute
to keep the name
field unique, but even without that code the errors keeps getting raised. So I'm not sure what is the actual cause here - does anyone know what I am doing wrong?
class AcademyFactory(factory.DjangoModelFactory):
class Meta:
model = 'core.Academy'
@factory.lazy_attribute
def name(self):
"""
The faker module has an habit of generating too many duplicate names
every now and then. We solve this by appending the name with the
instance.id
"""
return '{} {}'.format(
factory.Faker('company').generate(),
str(factory.Sequence(lambda n: ' {}'.format(n))._creation_counter),
)
class AcademySettingsFactory(factory.DjangoModelFactory):
class Meta:
model = 'core.AcademySettings'
academy = factory.SubFactory(AcademyFactory)
In all likelihood, you're defining self.academy_settings = AcademySettingsFactory
, thus referencing the class instead of getting an instance.
This can be fixed with the following:
def test__str__(self):
academy_settings = AcademySettingsFactory()
self.assertEqual(
"Academy settings for {}".format(academy_settings.academy),
str(academy_settings),
)
(Just a quick note: the call is self.assertEqual(expected, computed)
: put the expected value first, and the computed one last).