django/tests/regressiontests/model_inheritance_regress/tests.py

"""
Regression tests for Model inheritance behaviour.
"""

from __future__ import absolute_import

import datetime
from operator import attrgetter

from django.test import TestCase

from .models import (Place, Restaurant, ItalianRestaurant, ParkingLot,
    ParkingLot2, ParkingLot3, Supplier, Wholesaler, Child, SelfRefParent,
    SelfRefChild, ArticleWithAuthor, M2MChild, QualityControl, DerivedM,
    Person, BirthdayParty, BachelorParty, MessyBachelorParty,
    InternalCertificationAudit, BusStation, TrainStation)


class ModelInheritanceTest(TestCase):
    def test_model_inheritance(self):
        # Regression for #7350, #7202
        # Check that when you create a Parent object with a specific reference
        # to an existent child instance, saving the Parent doesn't duplicate
        # the child. This behaviour 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)

        # Check that 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': u"Guido's House of Pasta",
            'serves_hot_dogs': True
        }])

        dicts = list(ItalianRestaurant.objects.values(
            'name','serves_hot_dogs','serves_gnocchi'))
        self.assertEqual(dicts, [{
            'name': u"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': u'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': u"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': u"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': u'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': u"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.
        obj = Child.objects.create(
            name='child',
            created=datetime.datetime(2008, 6, 26, 17, 0, 0))
        dates = list(Child.objects.dates('created', 'month'))
        self.assertEqual(dates, [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)
        xx = Restaurant.objects.create(
            name='a',
            address='xx',
            serves_hot_dogs=True,
            serves_pizza=False)

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

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

    def test_issue_6755(self):
        """
        Regression test for #6755
        """
        r = Restaurant(serves_pizza=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)
        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)
        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)
        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 ocurr 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):
        """
        Regression tests for #10406
        If there's a one-to-one link between a child model and the parent and
        no explicit pk declared, we can use the one-to-one link as the pk on
        the child.
        """
        self.assertEqual(ParkingLot2._meta.pk.name, "parent")

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

    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):
        # Check that 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 = [p1, p3]

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

        # Check that a subclass of a subclass of an abstract model doesn't get
        # it's own accessor.
        self.assertFalse(hasattr(p2, 'messybachelorparty_set'))

        # ... but it does inherit the m2m from it's parent
        messy = MessyBachelorParty.objects.create(
            name='Bachelor party for Dave')
        messy.attendees = [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,
                u'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)