django/tests/model_fields/test_manytomanyfield.py

69 lines
2.4 KiB
Python

from django.apps import apps
from django.db import models
from django.test import SimpleTestCase
from django.test.utils import isolate_apps
class ManyToManyFieldTests(SimpleTestCase):
@isolate_apps('model_fields')
def test_value_from_object_instance_without_pk(self):
class ManyToManyModel(models.Model):
m2m = models.ManyToManyField('self', models.CASCADE)
instance = ManyToManyModel()
qs = instance._meta.get_field('m2m').value_from_object(instance)
self.assertEqual(qs.model, ManyToManyModel)
self.assertEqual(list(qs), [])
def test_abstract_model_pending_operations(self):
"""
Many-to-many fields declared on abstract models should not add lazy
relations to resolve relationship declared as string (#24215).
"""
pending_ops_before = list(apps._pending_operations.items())
class AbstractManyToManyModel(models.Model):
fk = models.ForeignKey('missing.FK', models.CASCADE)
class Meta:
abstract = True
self.assertIs(AbstractManyToManyModel._meta.apps, apps)
self.assertEqual(
pending_ops_before,
list(apps._pending_operations.items()),
'Pending lookup added for a many-to-many field on an abstract model'
)
@isolate_apps('model_fields', 'model_fields.tests')
def test_abstract_model_app_relative_foreign_key(self):
class AbstractReferent(models.Model):
reference = models.ManyToManyField('Referred', through='Through')
class Meta:
app_label = 'model_fields'
abstract = True
def assert_app_model_resolved(label):
class Referred(models.Model):
class Meta:
app_label = label
class Through(models.Model):
referred = models.ForeignKey('Referred', on_delete=models.CASCADE)
referent = models.ForeignKey('ConcreteReferent', on_delete=models.CASCADE)
class Meta:
app_label = label
class ConcreteReferent(AbstractReferent):
class Meta:
app_label = label
self.assertEqual(ConcreteReferent._meta.get_field('reference').related_model, Referred)
self.assertEqual(ConcreteReferent.reference.through, Through)
assert_app_model_resolved('model_fields')
assert_app_model_resolved('tests')