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django/tests/model_fields/test_manytomanyfield.py
2022-02-07 20:37:05 +01:00

108 lines
3.7 KiB
Python

from django.apps import apps
from django.db import models
from django.test import SimpleTestCase, TestCase
from django.test.utils import isolate_apps
from .models import ManyToMany
class ManyToManyFieldTests(SimpleTestCase):
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")
def test_invalid_to_parameter(self):
msg = (
"ManyToManyField(1) is invalid. First parameter to "
"ManyToManyField must be either a model, a model name, or the "
"string 'self'"
)
with self.assertRaisesMessage(TypeError, msg):
class MyModel(models.Model):
m2m = models.ManyToManyField(1)
@isolate_apps("model_fields")
def test_through_db_table_mutually_exclusive(self):
class Child(models.Model):
pass
class Through(models.Model):
referred = models.ForeignKey(Child, on_delete=models.CASCADE)
referent = models.ForeignKey(Child, on_delete=models.CASCADE)
msg = "Cannot specify a db_table if an intermediary model is used."
with self.assertRaisesMessage(ValueError, msg):
class MyModel(models.Model):
m2m = models.ManyToManyField(
Child,
through="Through",
db_table="custom_name",
)
class ManyToManyFieldDBTests(TestCase):
def test_value_from_object_instance_without_pk(self):
obj = ManyToMany()
self.assertEqual(obj._meta.get_field("m2m").value_from_object(obj), [])
def test_value_from_object_instance_with_pk(self):
obj = ManyToMany.objects.create()
related_obj = ManyToMany.objects.create()
obj.m2m.add(related_obj)
self.assertEqual(
obj._meta.get_field("m2m").value_from_object(obj), [related_obj]
)