from __future__ import unicode_literals
from django.db import connection
from django.test import TestCase
from .models import (Bar, Favorites, HiddenPointer, Place, Restaurant, Target,
UndergroundBar)
class OneToOneRegressionTests(TestCase):
def setUp(self):
self.p1 = Place(name='Demon Dogs', address='944 W. Fullerton')
self.p1.save()
self.r1 = Restaurant(place=self.p1, serves_hot_dogs=True, serves_pizza=False)
self.r1.save()
self.b1 = Bar(place=self.p1, serves_cocktails=False)
self.b1.save()
def test_reverse_relationship_cache_cascade(self):
"""
Regression test for #9023: accessing the reverse relationship shouldn't
result in a cascading delete().
"""
bar = UndergroundBar.objects.create(place=self.p1, serves_cocktails=False)
# The bug in #9023: if you access the one-to-one relation *before*
# setting to None and deleting, the cascade happens anyway.
self.p1.undergroundbar
bar.place.name = 'foo'
bar.place = None
bar.save()
self.p1.delete()
self.assertEqual(Place.objects.all().count(), 0)
self.assertEqual(UndergroundBar.objects.all().count(), 1)
def test_create_models_m2m(self):
"""
Regression test for #1064 and #1506
Check that we create models via the m2m relation if the remote model
has a OneToOneField.
"""
f = Favorites(name='Fred')
f.save()
f.restaurants = [self.r1]
self.assertQuerysetEqual(
f.restaurants.all(),
['<Restaurant: Demon Dogs the restaurant>']
)
def test_reverse_object_cache(self):
"""
Regression test for #7173
Check that the name of the cache for the reverse object is correct.
"""
self.assertEqual(self.p1.restaurant, self.r1)
self.assertEqual(self.p1.bar, self.b1)
def test_related_object_cache(self):
""" Regression test for #6886 (the related-object cache) """
# Look up the objects again so that we get "fresh" objects
p = Place.objects.get(name="Demon Dogs")
r = p.restaurant
# Accessing the related object again returns the exactly same object
self.assertTrue(p.restaurant is r)
# But if we kill the cache, we get a new object
del p._restaurant_cache
self.assertFalse(p.restaurant is r)
# Reassigning the Restaurant object results in an immediate cache update
# We can't use a new Restaurant because that'll violate one-to-one, but
# with a new *instance* the is test below will fail if #6886 regresses.
r2 = Restaurant.objects.get(pk=r.pk)
p.restaurant = r2
self.assertTrue(p.restaurant is r2)
# Assigning None succeeds if field is null=True.
ug_bar = UndergroundBar.objects.create(place=p, serves_cocktails=False)
ug_bar.place = None
self.assertTrue(ug_bar.place is None)
# Assigning None fails: Place.restaurant is null=False
self.assertRaises(ValueError, setattr, p, 'restaurant', None)
# You also can't assign an object of the wrong type here
self.assertRaises(ValueError, setattr, p, 'restaurant', p)
# Creation using keyword argument should cache the related object.
p = Place.objects.get(name="Demon Dogs")
r = Restaurant(place=p)
self.assertTrue(r.place is p)
# Creation using attname keyword argument and an id will cause the related
# object to be fetched.
p = Place.objects.get(name="Demon Dogs")
r = Restaurant(place_id=p.id)
self.assertFalse(r.place is p)
self.assertEqual(r.place, p)
def test_filter_one_to_one_relations(self):
"""
Regression test for #9968
filtering reverse one-to-one relations with primary_key=True was
misbehaving. We test both (primary_key=True & False) cases here to
prevent any reappearance of the problem.
"""
Target.objects.create()
self.assertQuerysetEqual(
Target.objects.filter(pointer=None),
['<Target: Target object>']
)
self.assertQuerysetEqual(
Target.objects.exclude(pointer=None),
[]
)
self.assertQuerysetEqual(
Target.objects.filter(second_pointer=None),
['<Target: Target object>']
)
self.assertQuerysetEqual(
Target.objects.exclude(second_pointer=None),
[]
)
def test_reverse_object_does_not_exist_cache(self):
"""
Regression for #13839 and #17439.
DoesNotExist on a reverse one-to-one relation is cached.
"""
p = Place(name='Zombie Cats', address='Not sure')
p.save()
with self.assertNumQueries(1):
with self.assertRaises(Restaurant.DoesNotExist):
p.restaurant
with self.assertNumQueries(0):
with self.assertRaises(Restaurant.DoesNotExist):
p.restaurant
def test_reverse_object_cached_when_related_is_accessed(self):
"""
Regression for #13839 and #17439.
The target of a one-to-one relation is cached
when the origin is accessed through the reverse relation.
"""
# Use a fresh object without caches
r = Restaurant.objects.get(pk=self.r1.pk)
p = r.place
with self.assertNumQueries(0):
self.assertEqual(p.restaurant, r)
def test_related_object_cached_when_reverse_is_accessed(self):
"""
Regression for #13839 and #17439.
The origin of a one-to-one relation is cached
when the target is accessed through the reverse relation.
"""
# Use a fresh object without caches
p = Place.objects.get(pk=self.p1.pk)
r = p.restaurant
with self.assertNumQueries(0):
self.assertEqual(r.place, p)
def test_reverse_object_cached_when_related_is_set(self):
"""
Regression for #13839 and #17439.
The target of a one-to-one relation is always cached.
"""
p = Place(name='Zombie Cats', address='Not sure')
p.save()
self.r1.place = p
self.r1.save()
with self.assertNumQueries(0):
self.assertEqual(p.restaurant, self.r1)
def test_reverse_object_cached_when_related_is_unset(self):
"""
Regression for #13839 and #17439.
The target of a one-to-one relation is always cached.
"""
b = UndergroundBar(place=self.p1, serves_cocktails=True)
b.save()
with self.assertNumQueries(0):
self.assertEqual(self.p1.undergroundbar, b)
b.place = None
b.save()
with self.assertNumQueries(0):
with self.assertRaises(UndergroundBar.DoesNotExist):
self.p1.undergroundbar
def test_get_reverse_on_unsaved_object(self):
"""
Regression for #18153 and #19089.
Accessing the reverse relation on an unsaved object
always raises an exception.
"""
p = Place()
# When there's no instance of the origin of the one-to-one
with self.assertNumQueries(0):
with self.assertRaises(UndergroundBar.DoesNotExist):
p.undergroundbar
UndergroundBar.objects.create()
# When there's one instance of the origin
# (p.undergroundbar used to return that instance)
with self.assertNumQueries(0):
with self.assertRaises(UndergroundBar.DoesNotExist):
p.undergroundbar
# Several instances of the origin are only possible if database allows
# inserting multiple NULL rows for a unique constraint
if connection.features.supports_nullable_unique_constraints:
UndergroundBar.objects.create()
# When there are several instances of the origin
with self.assertNumQueries(0):
with self.assertRaises(UndergroundBar.DoesNotExist):
p.undergroundbar
def test_set_reverse_on_unsaved_object(self):
"""
Writing to the reverse relation on an unsaved object
is impossible too.
"""
p = Place()
b = UndergroundBar.objects.create()
with self.assertNumQueries(0):
with self.assertRaises(ValueError):
p.undergroundbar = b
def test_nullable_o2o_delete(self):
u = UndergroundBar.objects.create(place=self.p1)
u.place_id = None
u.save()
self.p1.delete()
self.assertTrue(UndergroundBar.objects.filter(pk=u.pk).exists())
self.assertIsNone(UndergroundBar.objects.get(pk=u.pk).place)
def test_hidden_accessor(self):
"""
When a '+' ending related name is specified no reverse accessor should
be added to the related model.
"""
self.assertFalse(
hasattr(Target, HiddenPointer._meta.get_field('target').related.get_accessor_name())
)