from io import StringIO from django.contrib.auth.models import User from django.core import management from django.test import TestCase from .models import Car, CarDriver, Driver, Group, Membership, Person, UserMembership class M2MThroughTestCase(TestCase): @classmethod def setUpTestData(cls): cls.bob = Person.objects.create(name="Bob") cls.jim = Person.objects.create(name="Jim") cls.rock = Group.objects.create(name="Rock") cls.roll = Group.objects.create(name="Roll") cls.frank = User.objects.create_user("frank", "frank@example.com", "password") cls.jane = User.objects.create_user("jane", "jane@example.com", "password") # normal intermediate model cls.bob_rock = Membership.objects.create(person=cls.bob, group=cls.rock) cls.bob_roll = Membership.objects.create( person=cls.bob, group=cls.roll, price=50 ) cls.jim_rock = Membership.objects.create( person=cls.jim, group=cls.rock, price=50 ) # intermediate model with custom id column cls.frank_rock = UserMembership.objects.create(user=cls.frank, group=cls.rock) cls.frank_roll = UserMembership.objects.create(user=cls.frank, group=cls.roll) cls.jane_rock = UserMembership.objects.create(user=cls.jane, group=cls.rock) def test_retrieve_reverse_m2m_items(self): self.assertCountEqual(self.bob.group_set.all(), [self.rock, self.roll]) def test_retrieve_forward_m2m_items(self): self.assertSequenceEqual(self.roll.members.all(), [self.bob]) def test_retrieve_reverse_m2m_items_via_custom_id_intermediary(self): self.assertCountEqual(self.frank.group_set.all(), [self.rock, self.roll]) def test_retrieve_forward_m2m_items_via_custom_id_intermediary(self): self.assertSequenceEqual(self.roll.user_members.all(), [self.frank]) def test_join_trimming_forwards(self): """ Too many copies of the intermediate table aren't involved when doing a join (#8046, #8254). """ self.assertSequenceEqual( self.rock.members.filter(membership__price=50), [self.jim], ) def test_join_trimming_reverse(self): self.assertSequenceEqual( self.bob.group_set.filter(membership__price=50), [self.roll], ) class M2MThroughSerializationTestCase(TestCase): @classmethod def setUpTestData(cls): cls.bob = Person.objects.create(name="Bob") cls.roll = Group.objects.create(name="Roll") cls.bob_roll = Membership.objects.create(person=cls.bob, group=cls.roll) def test_serialization(self): "m2m-through models aren't serialized as m2m fields. Refs #8134" pks = { "p_pk": self.bob.pk, "g_pk": self.roll.pk, "m_pk": self.bob_roll.pk, "app_label": "m2m_through_regress", } out = StringIO() management.call_command( "dumpdata", "m2m_through_regress", format="json", stdout=out ) self.assertJSONEqual( out.getvalue().strip(), '[{"pk": %(m_pk)s, "model": "m2m_through_regress.membership", ' '"fields": {"person": %(p_pk)s, "price": 100, "group": %(g_pk)s}}, ' '{"pk": %(p_pk)s, "model": "m2m_through_regress.person", ' '"fields": {"name": "Bob"}}, ' '{"pk": %(g_pk)s, "model": "m2m_through_regress.group", ' '"fields": {"name": "Roll"}}]' % pks, ) out = StringIO() management.call_command( "dumpdata", "m2m_through_regress", format="xml", indent=2, stdout=out ) self.assertXMLEqual( out.getvalue().strip(), """ %(p_pk)s %(g_pk)s 100 Bob Roll """.strip() % pks, ) class ToFieldThroughTests(TestCase): @classmethod def setUpTestData(cls): cls.car = Car.objects.create(make="Toyota") cls.driver = Driver.objects.create(name="Ryan Briscoe") CarDriver.objects.create(car=cls.car, driver=cls.driver) # We are testing if wrong objects get deleted due to using wrong # field value in m2m queries. So, it is essential that the pk # numberings do not match. # Create one intentionally unused driver to mix up the autonumbering cls.unused_driver = Driver.objects.create(name="Barney Gumble") # And two intentionally unused cars. cls.unused_car1 = Car.objects.create(make="Trabant") cls.unused_car2 = Car.objects.create(make="Wartburg") def test_to_field(self): self.assertSequenceEqual(self.car.drivers.all(), [self.driver]) def test_to_field_reverse(self): self.assertSequenceEqual(self.driver.car_set.all(), [self.car]) def test_to_field_clear_reverse(self): self.driver.car_set.clear() self.assertSequenceEqual(self.driver.car_set.all(), []) def test_to_field_clear(self): self.car.drivers.clear() self.assertSequenceEqual(self.car.drivers.all(), []) # Low level tests for _add_items and _remove_items. We test these methods # because .add/.remove aren't available for m2m fields with through, but # through is the only way to set to_field currently. We do want to make # sure these methods are ready if the ability to use .add or .remove with # to_field relations is added some day. def test_add(self): self.assertSequenceEqual(self.car.drivers.all(), [self.driver]) # Yikes - barney is going to drive... self.car.drivers._add_items("car", "driver", self.unused_driver) self.assertSequenceEqual( self.car.drivers.all(), [self.unused_driver, self.driver], ) def test_m2m_relations_unusable_on_null_to_field(self): nullcar = Car(make=None) msg = ( '"" needs to have a value for field "make" before this ' "many-to-many relationship can be used." ) with self.assertRaisesMessage(ValueError, msg): nullcar.drivers.all() def test_m2m_relations_unusable_on_null_pk_obj(self): msg = ( "'Car' instance needs to have a primary key value before a " "many-to-many relationship can be used." ) with self.assertRaisesMessage(ValueError, msg): Car(make="Ford").drivers.all() def test_add_related_null(self): nulldriver = Driver.objects.create(name=None) msg = 'Cannot add "": the value for field "driver" is None' with self.assertRaisesMessage(ValueError, msg): self.car.drivers._add_items("car", "driver", nulldriver) def test_add_reverse(self): car2 = Car.objects.create(make="Honda") self.assertCountEqual(self.driver.car_set.all(), [self.car]) self.driver.car_set._add_items("driver", "car", car2) self.assertCountEqual(self.driver.car_set.all(), [self.car, car2]) def test_add_null_reverse(self): nullcar = Car.objects.create(make=None) msg = 'Cannot add "": the value for field "car" is None' with self.assertRaisesMessage(ValueError, msg): self.driver.car_set._add_items("driver", "car", nullcar) def test_add_null_reverse_related(self): nulldriver = Driver.objects.create(name=None) msg = ( '"" needs to have a value for field "name" before ' "this many-to-many relationship can be used." ) with self.assertRaisesMessage(ValueError, msg): nulldriver.car_set._add_items("driver", "car", self.car) def test_remove(self): self.assertSequenceEqual(self.car.drivers.all(), [self.driver]) self.car.drivers._remove_items("car", "driver", self.driver) self.assertSequenceEqual(self.car.drivers.all(), []) def test_remove_reverse(self): self.assertSequenceEqual(self.driver.car_set.all(), [self.car]) self.driver.car_set._remove_items("driver", "car", self.car) self.assertSequenceEqual(self.driver.car_set.all(), []) class ThroughLoadDataTestCase(TestCase): fixtures = ["m2m_through"] def test_sequence_creation(self): """ Sequences on an m2m_through are created for the through model, not a phantom auto-generated m2m table (#11107). """ out = StringIO() management.call_command( "dumpdata", "m2m_through_regress", format="json", stdout=out ) self.assertJSONEqual( out.getvalue().strip(), '[{"pk": 1, "model": "m2m_through_regress.usermembership", ' '"fields": {"price": 100, "group": 1, "user": 1}}, ' '{"pk": 1, "model": "m2m_through_regress.person", ' '"fields": {"name": "Guido"}}, ' '{"pk": 1, "model": "m2m_through_regress.group", ' '"fields": {"name": "Python Core Group"}}]', )