python-3.x - 在 FactoryBoy 中,如何使用空的多对多成员字段设置我的工厂?
问题描述
我将 Django 3 与 Python 3.8 一起使用。我有以下型号...
class Coop(models.Model):
objects = CoopManager()
name = models.CharField(max_length=250, null=False)
types = models.ManyToManyField(CoopType, blank=False)
addresses = models.ManyToManyField(Address)
enabled = models.BooleanField(default=True, null=False)
phone = models.ForeignKey(ContactMethod, on_delete=models.CASCADE, null=True, related_name='contact_phone')
email = models.ForeignKey(ContactMethod, on_delete=models.CASCADE, null=True, related_name='contact_email')
web_site = models.TextField()
我创建了以下工厂(使用工厂男孩)尝试在测试中创建模型......
class CoopFactory(factory.DjangoModelFactory):
"""
Define Coop Factory
"""
class Meta:
model = Coop
name = "test model"
enabled = True
phone = factory.SubFactory(PhoneContactMethodFactory)
email = factory.SubFactory(EmailContactMethodFactory)
web_site = "http://www.hello.com"
@factory.post_generation
def addresses(self, create, extracted, **kwargs):
if not create:
# Simple build, do nothing.
return
if extracted:
# A list of types were passed in, use them
for address in extracted:
self.addresses.add(address)
else:
address = AddressFactory()
self.addresses.add( address )
@factory.post_generation
def types(self, create, extracted, **kwargs):
if not create:
# Simple build, do nothing.
return
if extracted:
# A list of types were passed in, use them
for type in extracted:
self.types.add(type)
else:
print("Creating type ...\n")
type = CoopTypeFactory()
self.types.add( type )
但我无法创建一个多对多字段(类型)为空的工厂。我尝试了以下
@pytest.mark.django_db
def test_coop_create_with_no_types(self):
""" Test customer model """ # create customer model instance
coop = CoopFactory.create(types=[])
print("size: ", coop.types.all().count())
self.assertIsNotNone(coop)
self.assertIsNotNone( coop.id )
但是 的值types.all().count()
始终等于 1。如何正确设置具有空多对多字段的工厂?
编辑:针对给出的答案,传递工厂使用的成员字段的正确方法是什么?我试过了
@pytest.mark.django_db
def test_coop_create_with_existing_type(self):
""" Test customer model """ # create customer model instance
coop_from_factory = CoopFactory()
self.assertIsNotNone(coop_from_factory)
coop_types = coop_from_factory.types
coop = CoopFactory.create(types=[coop_types.all().first()], addresses=coop_from_factory.addresses.all())
self.assertIsNotNone(coop)
但出现此错误,对于“for _ in range(extracted):”行...
Traceback (most recent call last):
File "/Users/davea/Documents/workspace/chicommons/maps/web/tests/test_models.py", line 48, in test_coop_create_with_existing_type
coop = CoopFactory.create(types=coop_types, addresses=coop_from_factory.addresses.all())
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/factory/base.py", line 564, in create
return cls._generate(enums.CREATE_STRATEGY, kwargs)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/factory/django.py", line 141, in _generate
return super(DjangoModelFactory, cls)._generate(strategy, params)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/factory/base.py", line 501, in _generate
return step.build()
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/factory/builder.py", line 296, in build
postgen_results[declaration_name] = declaration.declaration.call(
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/factory/declarations.py", line 622, in call
return self.function(
File "/Users/davea/Documents/workspace/chicommons/maps/web/tests/factories.py", line 128, in types
for _ in range(extracted):
TypeError: 'ManyRelatedManager' object cannot be interpreted as an integer
解决方案
解决方法是更改if extracted
为if extracted is not None
.
解释
在 Python 中,空列表是错误的1但不是None
。
coop = CoopFactory.create(types=[])
空列表作为参数[]
传递给后生成挂钩。types
extracted
@factory.post_generation def types(self, create, extracted, **kwargs): if not create: # Simple build, do nothing. return if extracted: # A list of types were passed in, use them for type in extracted: self.types.add(type) else: print("Creating type ...\n") type = CoopTypeFactory() self.types.add( type )
由于if extracted
是真值测试1,虚假空列表落到创建else
a 的块中type
。因此, 的值types.all().count()
等于 1。
1 https://docs.python.org/3/library/stdtypes.html#truth-value-testing
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