django/tests/model_inheritance_regress/tests.py

"""
Regression tests for Model inheritance behavior.
"""
from __future__ import unicode_literals

import datetime
from operator import attrgetter
from unittest import expectedFailure

from django import forms
from django.test import TestCase

from .models import (
    ArticleWithAuthor, BachelorParty, BirthdayParty, BusStation, Child,
    DerivedM, InternalCertificationAudit, ItalianRestaurant, M2MChild,
    MessyBachelorParty, ParkingLot, ParkingLot3, ParkingLot4A, ParkingLot4B,
    Person, Place, Profile, QualityControl, Restaurant, SelfRefChild,
    SelfRefParent, Senator, Supplier, TrainStation, User, Wholesaler,
)


class ModelInheritanceTest(TestCase):
    def test_model_inheritance(self):
        # Regression for #7350, #7202
        # When you create a Parent object with a specific reference to an
        # existent child instance, saving the Parent doesn't duplicate the
        # child. This behavior is only activated during a raw save - it is
        # mostly relevant to deserialization, but any sort of CORBA style
        # 'narrow()' API would require a similar approach.

        # Create a child-parent-grandparent chain
        place1 = Place(
            name="Guido's House of Pasta",
            address='944 W. Fullerton')
        place1.save_base(raw=True)
        restaurant = Restaurant(
            place_ptr=place1,
            serves_hot_dogs=True,
            serves_pizza=False)
        restaurant.save_base(raw=True)
        italian_restaurant = ItalianRestaurant(
            restaurant_ptr=restaurant,
            serves_gnocchi=True)
        italian_restaurant.save_base(raw=True)

        # Create a child-parent chain with an explicit parent link
        place2 = Place(name='Main St', address='111 Main St')
        place2.save_base(raw=True)
        park = ParkingLot(parent=place2, capacity=100)
        park.save_base(raw=True)

        # No extra parent objects have been created.
        places = list(Place.objects.all())
        self.assertEqual(places, [place1, place2])

        dicts = list(Restaurant.objects.values('name', 'serves_hot_dogs'))
        self.assertEqual(dicts, [{
            'name': "Guido's House of Pasta",
            'serves_hot_dogs': True
        }])

        dicts = list(ItalianRestaurant.objects.values(
            'name', 'serves_hot_dogs', 'serves_gnocchi'))
        self.assertEqual(dicts, [{
            'name': "Guido's House of Pasta",
            'serves_gnocchi': True,
            'serves_hot_dogs': True,
        }])

        dicts = list(ParkingLot.objects.values('name', 'capacity'))
        self.assertEqual(dicts, [{
            'capacity': 100,
            'name': 'Main St',
        }])

        # You can also update objects when using a raw save.
        place1.name = "Guido's All New House of Pasta"
        place1.save_base(raw=True)

        restaurant.serves_hot_dogs = False
        restaurant.save_base(raw=True)

        italian_restaurant.serves_gnocchi = False
        italian_restaurant.save_base(raw=True)

        place2.name = 'Derelict lot'
        place2.save_base(raw=True)

        park.capacity = 50
        park.save_base(raw=True)

        # No extra parent objects after an update, either.
        places = list(Place.objects.all())
        self.assertEqual(places, [place2, place1])
        self.assertEqual(places[0].name, 'Derelict lot')
        self.assertEqual(places[1].name, "Guido's All New House of Pasta")

        dicts = list(Restaurant.objects.values('name', 'serves_hot_dogs'))
        self.assertEqual(dicts, [{
            'name': "Guido's All New House of Pasta",
            'serves_hot_dogs': False,
        }])

        dicts = list(ItalianRestaurant.objects.values(
            'name', 'serves_hot_dogs', 'serves_gnocchi'))
        self.assertEqual(dicts, [{
            'name': "Guido's All New House of Pasta",
            'serves_gnocchi': False,
            'serves_hot_dogs': False,
        }])

        dicts = list(ParkingLot.objects.values('name', 'capacity'))
        self.assertEqual(dicts, [{
            'capacity': 50,
            'name': 'Derelict lot',
        }])

        # If you try to raw_save a parent attribute onto a child object,
        # the attribute will be ignored.

        italian_restaurant.name = "Lorenzo's Pasta Hut"
        italian_restaurant.save_base(raw=True)

        # Note that the name has not changed
        # - name is an attribute of Place, not ItalianRestaurant
        dicts = list(ItalianRestaurant.objects.values(
            'name', 'serves_hot_dogs', 'serves_gnocchi'))
        self.assertEqual(dicts, [{
            'name': "Guido's All New House of Pasta",
            'serves_gnocchi': False,
            'serves_hot_dogs': False,
        }])

    def test_issue_7105(self):
        # Regressions tests for #7105: dates() queries should be able to use
        # fields from the parent model as easily as the child.
        Child.objects.create(
            name='child',
            created=datetime.datetime(2008, 6, 26, 17, 0, 0))
        datetimes = list(Child.objects.datetimes('created', 'month'))
        self.assertEqual(datetimes, [datetime.datetime(2008, 6, 1, 0, 0)])

    def test_issue_7276(self):
        # Regression test for #7276: calling delete() on a model with
        # multi-table inheritance should delete the associated rows from any
        # ancestor tables, as well as any descendent objects.
        place1 = Place(
            name="Guido's House of Pasta",
            address='944 W. Fullerton')
        place1.save_base(raw=True)
        restaurant = Restaurant(
            place_ptr=place1,
            serves_hot_dogs=True,
            serves_pizza=False)
        restaurant.save_base(raw=True)
        italian_restaurant = ItalianRestaurant(
            restaurant_ptr=restaurant,
            serves_gnocchi=True)
        italian_restaurant.save_base(raw=True)

        ident = ItalianRestaurant.objects.all()[0].id
        self.assertEqual(Place.objects.get(pk=ident), place1)
        Restaurant.objects.create(
            name='a',
            address='xx',
            serves_hot_dogs=True,
            serves_pizza=False)

        # This should delete both Restaurants, plus the related places, plus
        # the ItalianRestaurant.
        Restaurant.objects.all().delete()

        with self.assertRaises(Place.DoesNotExist):
            Place.objects.get(pk=ident)
        with self.assertRaises(ItalianRestaurant.DoesNotExist):
            ItalianRestaurant.objects.get(pk=ident)

    def test_issue_6755(self):
        """
        Regression test for #6755
        """
        r = Restaurant(serves_pizza=False, serves_hot_dogs=False)
        r.save()
        self.assertEqual(r.id, r.place_ptr_id)
        orig_id = r.id
        r = Restaurant(place_ptr_id=orig_id, serves_pizza=True, serves_hot_dogs=False)
        r.save()
        self.assertEqual(r.id, orig_id)
        self.assertEqual(r.id, r.place_ptr_id)

    def test_issue_7488(self):
        # Regression test for #7488. This looks a little crazy, but it's the
        # equivalent of what the admin interface has to do for the edit-inline
        # case.
        suppliers = Supplier.objects.filter(
            restaurant=Restaurant(name='xx', address='yy'))
        suppliers = list(suppliers)
        self.assertEqual(suppliers, [])

    def test_issue_11764(self):
        """
        Regression test for #11764
        """
        wholesalers = list(Wholesaler.objects.all().select_related())
        self.assertEqual(wholesalers, [])

    def test_issue_7853(self):
        """
        Regression test for #7853
        If the parent class has a self-referential link, make sure that any
        updates to that link via the child update the right table.
        """
        obj = SelfRefChild.objects.create(child_data=37, parent_data=42)
        obj.delete()

    def test_get_next_previous_by_date(self):
        """
        Regression tests for #8076
        get_(next/previous)_by_date should work
        """
        c1 = ArticleWithAuthor(
            headline='ArticleWithAuthor 1',
            author="Person 1",
            pub_date=datetime.datetime(2005, 8, 1, 3, 0))
        c1.save()
        c2 = ArticleWithAuthor(
            headline='ArticleWithAuthor 2',
            author="Person 2",
            pub_date=datetime.datetime(2005, 8, 1, 10, 0))
        c2.save()
        c3 = ArticleWithAuthor(
            headline='ArticleWithAuthor 3',
            author="Person 3",
            pub_date=datetime.datetime(2005, 8, 2))
        c3.save()

        self.assertEqual(c1.get_next_by_pub_date(), c2)
        self.assertEqual(c2.get_next_by_pub_date(), c3)
        with self.assertRaises(ArticleWithAuthor.DoesNotExist):
            c3.get_next_by_pub_date()
        self.assertEqual(c3.get_previous_by_pub_date(), c2)
        self.assertEqual(c2.get_previous_by_pub_date(), c1)
        with self.assertRaises(ArticleWithAuthor.DoesNotExist):
            c1.get_previous_by_pub_date()

    def test_inherited_fields(self):
        """
        Regression test for #8825 and #9390
        Make sure all inherited fields (esp. m2m fields, in this case) appear
        on the child class.
        """
        m2mchildren = list(M2MChild.objects.filter(articles__isnull=False))
        self.assertEqual(m2mchildren, [])

        # Ordering should not include any database column more than once (this
        # is most likely to occur naturally with model inheritance, so we
        # check it here). Regression test for #9390. This necessarily pokes at
        # the SQL string for the query, since the duplicate problems are only
        # apparent at that late stage.
        qs = ArticleWithAuthor.objects.order_by('pub_date', 'pk')
        sql = qs.query.get_compiler(qs.db).as_sql()[0]
        fragment = sql[sql.find('ORDER BY'):]
        pos = fragment.find('pub_date')
        self.assertEqual(fragment.find('pub_date', pos + 1), -1)

    def test_queryset_update_on_parent_model(self):
        """
        Regression test for #10362
        It is possible to call update() and only change a field in
        an ancestor model.
        """
        article = ArticleWithAuthor.objects.create(
            author="fred",
            headline="Hey there!",
            pub_date=datetime.datetime(2009, 3, 1, 8, 0, 0))
        update = ArticleWithAuthor.objects.filter(
            author="fred").update(headline="Oh, no!")
        self.assertEqual(update, 1)
        update = ArticleWithAuthor.objects.filter(
            pk=article.pk).update(headline="Oh, no!")
        self.assertEqual(update, 1)

        derivedm1 = DerivedM.objects.create(
            customPK=44,
            base_name="b1",
            derived_name="d1")
        self.assertEqual(derivedm1.customPK, 44)
        self.assertEqual(derivedm1.base_name, 'b1')
        self.assertEqual(derivedm1.derived_name, 'd1')
        derivedms = list(DerivedM.objects.all())
        self.assertEqual(derivedms, [derivedm1])

    def test_use_explicit_o2o_to_parent_as_pk(self):
        """
        The connector from child to parent need not be the pk on the child.
        """
        self.assertEqual(ParkingLot3._meta.pk.name, "primary_key")
        # the child->parent link
        self.assertEqual(ParkingLot3._meta.get_ancestor_link(Place).name, "parent")

    def test_use_explicit_o2o_to_parent_from_abstract_model(self):
        self.assertEqual(ParkingLot4A._meta.pk.name, "parent")
        ParkingLot4A.objects.create(
            name="Parking4A",
            address='21 Jump Street',
        )

        self.assertEqual(ParkingLot4B._meta.pk.name, "parent")
        ParkingLot4A.objects.create(
            name="Parking4B",
            address='21 Jump Street',
        )

    def test_all_fields_from_abstract_base_class(self):
        """
        Regression tests for #7588
        """
        # All fields from an ABC, including those inherited non-abstractly
        # should be available on child classes (#7588). Creating this instance
        # should work without error.
        QualityControl.objects.create(
            headline="Problems in Django",
            pub_date=datetime.datetime.now(),
            quality=10,
            assignee="adrian")

    def test_abstract_base_class_m2m_relation_inheritance(self):
        # many-to-many relations defined on an abstract base class are
        # correctly inherited (and created) on the child class.
        p1 = Person.objects.create(name='Alice')
        p2 = Person.objects.create(name='Bob')
        p3 = Person.objects.create(name='Carol')
        p4 = Person.objects.create(name='Dave')

        birthday = BirthdayParty.objects.create(
            name='Birthday party for Alice')
        birthday.attendees.set([p1, p3])

        bachelor = BachelorParty.objects.create(name='Bachelor party for Bob')
        bachelor.attendees.set([p2, p4])

        parties = list(p1.birthdayparty_set.all())
        self.assertEqual(parties, [birthday])

        parties = list(p1.bachelorparty_set.all())
        self.assertEqual(parties, [])

        parties = list(p2.bachelorparty_set.all())
        self.assertEqual(parties, [bachelor])

        # A subclass of a subclass of an abstract model doesn't get its own
        # accessor.
        self.assertFalse(hasattr(p2, 'messybachelorparty_set'))

        # ... but it does inherit the m2m from its parent
        messy = MessyBachelorParty.objects.create(
            name='Bachelor party for Dave')
        messy.attendees.set([p4])
        messy_parent = messy.bachelorparty_ptr

        parties = list(p4.bachelorparty_set.all())
        self.assertEqual(parties, [bachelor, messy_parent])

    def test_abstract_verbose_name_plural_inheritance(self):
        """
        verbose_name_plural correctly inherited from ABC if inheritance chain
        includes an abstract model.
        """
        # Regression test for #11369: verbose_name_plural should be inherited
        # from an ABC even when there are one or more intermediate
        # abstract models in the inheritance chain, for consistency with
        # verbose_name.
        self.assertEqual(
            InternalCertificationAudit._meta.verbose_name_plural,
            'Audits'
        )

    def test_inherited_nullable_exclude(self):
        obj = SelfRefChild.objects.create(child_data=37, parent_data=42)
        self.assertQuerysetEqual(
            SelfRefParent.objects.exclude(self_data=72), [
                obj.pk
            ],
            attrgetter("pk")
        )
        self.assertQuerysetEqual(
            SelfRefChild.objects.exclude(self_data=72), [
                obj.pk
            ],
            attrgetter("pk")
        )

    def test_concrete_abstract_concrete_pk(self):
        """
        Primary key set correctly with concrete->abstract->concrete inheritance.
        """
        # Regression test for #13987: Primary key is incorrectly determined
        # when more than one model has a concrete->abstract->concrete
        # inheritance hierarchy.
        self.assertEqual(
            len([field for field in BusStation._meta.local_fields if field.primary_key]),
            1
        )
        self.assertEqual(
            len([field for field in TrainStation._meta.local_fields if field.primary_key]),
            1
        )
        self.assertIs(BusStation._meta.pk.model, BusStation)
        self.assertIs(TrainStation._meta.pk.model, TrainStation)

    def test_inherited_unique_field_with_form(self):
        """
        A model which has different primary key for the parent model passes
        unique field checking correctly (#17615).
        """
        class ProfileForm(forms.ModelForm):
            class Meta:
                model = Profile
                fields = '__all__'

        User.objects.create(username="user_only")
        p = Profile.objects.create(username="user_with_profile")
        form = ProfileForm({'username': "user_with_profile", 'extra': "hello"}, instance=p)
        self.assertTrue(form.is_valid())

    def test_inheritance_joins(self):
        # Test for #17502 - check that filtering through two levels of
        # inheritance chain doesn't generate extra joins.
        qs = ItalianRestaurant.objects.all()
        self.assertEqual(str(qs.query).count('JOIN'), 2)
        qs = ItalianRestaurant.objects.filter(name='foo')
        self.assertEqual(str(qs.query).count('JOIN'), 2)

    @expectedFailure
    def test_inheritance_values_joins(self):
        # It would be nice (but not too important) to skip the middle join in
        # this case. Skipping is possible as nothing from the middle model is
        # used in the qs and top contains direct pointer to the bottom model.
        qs = ItalianRestaurant.objects.values_list('serves_gnocchi').filter(name='foo')
        self.assertEqual(str(qs.query).count('JOIN'), 1)

    def test_issue_21554(self):
        senator = Senator.objects.create(name='John Doe', title='X', state='Y')
        senator = Senator.objects.get(pk=senator.pk)
        self.assertEqual(senator.name, 'John Doe')
        self.assertEqual(senator.title, 'X')
        self.assertEqual(senator.state, 'Y')

    def test_inheritance_resolve_columns(self):
        Restaurant.objects.create(name='Bobs Cafe', address="Somewhere",
                                  serves_pizza=True, serves_hot_dogs=True)
        p = Place.objects.all().select_related('restaurant')[0]
        self.assertIsInstance(p.restaurant.serves_pizza, bool)

    def test_inheritance_select_related(self):
        # Regression test for #7246
        r1 = Restaurant.objects.create(
            name="Nobu", serves_hot_dogs=True, serves_pizza=False
        )
        r2 = Restaurant.objects.create(
            name="Craft", serves_hot_dogs=False, serves_pizza=True
        )
        Supplier.objects.create(name="John", restaurant=r1)
        Supplier.objects.create(name="Jane", restaurant=r2)

        self.assertQuerysetEqual(
            Supplier.objects.order_by("name").select_related(), [
                "Jane",
                "John",
            ],
            attrgetter("name")
        )

        jane = Supplier.objects.order_by("name").select_related("restaurant")[0]
        self.assertEqual(jane.restaurant.name, "Craft")

    def test_related_filtering_query_efficiency_ticket_15844(self):
        r = Restaurant.objects.create(
            name="Guido's House of Pasta",
            address='944 W. Fullerton',
            serves_hot_dogs=True,
            serves_pizza=False,
        )
        s = Supplier.objects.create(restaurant=r)
        with self.assertNumQueries(1):
            self.assertSequenceEqual(Supplier.objects.filter(restaurant=r), [s])
        with self.assertNumQueries(1):
            self.assertSequenceEqual(r.supplier_set.all(), [s])

    def test_queries_on_parent_access(self):
        italian_restaurant = ItalianRestaurant.objects.create(
            name="Guido's House of Pasta",
            address='944 W. Fullerton',
            serves_hot_dogs=True,
            serves_pizza=False,
            serves_gnocchi=True,
        )

        # No queries are made when accessing the parent objects.
        italian_restaurant = ItalianRestaurant.objects.get(pk=italian_restaurant.pk)
        with self.assertNumQueries(0):
            restaurant = italian_restaurant.restaurant_ptr
            self.assertEqual(restaurant.place_ptr.restaurant, restaurant)
            self.assertEqual(restaurant.italianrestaurant, italian_restaurant)

        # One query is made when accessing the parent objects when the instance
        # is deferred.
        italian_restaurant = ItalianRestaurant.objects.only('serves_gnocchi').get(pk=italian_restaurant.pk)
        with self.assertNumQueries(1):
            restaurant = italian_restaurant.restaurant_ptr
            self.assertEqual(restaurant.place_ptr.restaurant, restaurant)
            self.assertEqual(restaurant.italianrestaurant, italian_restaurant)

        # No queries are made when accessing the parent objects when the
        # instance has deferred a field not present in the parent table.
        italian_restaurant = ItalianRestaurant.objects.defer('serves_gnocchi').get(pk=italian_restaurant.pk)
        with self.assertNumQueries(0):
            restaurant = italian_restaurant.restaurant_ptr
            self.assertEqual(restaurant.place_ptr.restaurant, restaurant)
            self.assertEqual(restaurant.italianrestaurant, italian_restaurant)