0
0
mirror of https://github.com/django/django.git synced 2024-11-24 02:47:35 +01:00
django/tests/defer_regress/tests.py
Simon Charette 83f5478225 Fixed #35356 -- Deferred self-referential foreign key fields adequately.
While refs #34612 surfaced issues with reverse one-to-one fields
deferrals, it missed that switching to storing remote fields would break
self-referential relationships.

This change switches to storing related objects in the select mask
instead of remote fields to prevent collisions when dealing with
self-referential relationships that might have a different directional
mask.

Despite fixing #21204 introduced a crash under some self-referential
deferral conditions, it was simply not working even before that as it
aggregated the sets of deferred fields by model.

Thanks Joshua van Besouw for the report and Mariusz Felisiak for the
review.
2024-04-23 13:17:17 -03:00

369 lines
15 KiB
Python

from operator import attrgetter
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.db.models import Count
from django.test import TestCase
from .models import (
Base,
Child,
Derived,
Feature,
Item,
ItemAndSimpleItem,
Leaf,
Location,
OneToOneItem,
Proxy,
ProxyRelated,
RelatedItem,
Request,
ResolveThis,
SimpleItem,
SpecialFeature,
)
class DeferRegressionTest(TestCase):
def test_basic(self):
# Deferred fields should really be deferred and not accidentally use
# the field's default value just because they aren't passed to __init__
Item.objects.create(name="first", value=42)
obj = Item.objects.only("name", "other_value").get(name="first")
# Accessing "name" doesn't trigger a new database query. Accessing
# "value" or "text" should.
with self.assertNumQueries(0):
self.assertEqual(obj.name, "first")
self.assertEqual(obj.other_value, 0)
with self.assertNumQueries(1):
self.assertEqual(obj.value, 42)
with self.assertNumQueries(1):
self.assertEqual(obj.text, "xyzzy")
with self.assertNumQueries(0):
self.assertEqual(obj.text, "xyzzy")
# Regression test for #10695. Make sure different instances don't
# inadvertently share data in the deferred descriptor objects.
i = Item.objects.create(name="no I'm first", value=37)
items = Item.objects.only("value").order_by("-value")
self.assertEqual(items[0].name, "first")
self.assertEqual(items[1].name, "no I'm first")
RelatedItem.objects.create(item=i)
r = RelatedItem.objects.defer("item").get()
self.assertEqual(r.item_id, i.id)
self.assertEqual(r.item, i)
# Some further checks for select_related() and inherited model
# behavior (regression for #10710).
c1 = Child.objects.create(name="c1", value=42)
c2 = Child.objects.create(name="c2", value=37)
Leaf.objects.create(name="l1", child=c1, second_child=c2)
obj = Leaf.objects.only("name", "child").select_related()[0]
self.assertEqual(obj.child.name, "c1")
self.assertQuerySetEqual(
Leaf.objects.select_related().only("child__name", "second_child__name"),
[
"l1",
],
attrgetter("name"),
)
# Models instances with deferred fields should still return the same
# content types as their non-deferred versions (bug #10738).
ctype = ContentType.objects.get_for_model
c1 = ctype(Item.objects.all()[0])
c2 = ctype(Item.objects.defer("name")[0])
c3 = ctype(Item.objects.only("name")[0])
self.assertTrue(c1 is c2 is c3)
# Regression for #10733 - only() can be used on a model with two
# foreign keys.
results = Leaf.objects.only("name", "child", "second_child").select_related()
self.assertEqual(results[0].child.name, "c1")
self.assertEqual(results[0].second_child.name, "c2")
results = Leaf.objects.only(
"name", "child", "second_child", "child__name", "second_child__name"
).select_related()
self.assertEqual(results[0].child.name, "c1")
self.assertEqual(results[0].second_child.name, "c2")
# Regression for #16409 - make sure defer() and only() work with annotate()
self.assertIsInstance(
list(SimpleItem.objects.annotate(Count("feature")).defer("name")), list
)
self.assertIsInstance(
list(SimpleItem.objects.annotate(Count("feature")).only("name")), list
)
def test_ticket_16409(self):
# Regression for #16409 - make sure defer() and only() work with annotate()
self.assertIsInstance(
list(SimpleItem.objects.annotate(Count("feature")).defer("name")), list
)
self.assertIsInstance(
list(SimpleItem.objects.annotate(Count("feature")).only("name")), list
)
def test_ticket_23270(self):
d = Derived.objects.create(text="foo", other_text="bar")
with self.assertNumQueries(1):
obj = Base.objects.select_related("derived").defer("text")[0]
self.assertIsInstance(obj.derived, Derived)
self.assertEqual("bar", obj.derived.other_text)
self.assertNotIn("text", obj.__dict__)
self.assertEqual(d.pk, obj.derived.base_ptr_id)
def test_only_and_defer_usage_on_proxy_models(self):
# Regression for #15790 - only() broken for proxy models
proxy = Proxy.objects.create(name="proxy", value=42)
msg = "QuerySet.only() return bogus results with proxy models"
dp = Proxy.objects.only("other_value").get(pk=proxy.pk)
self.assertEqual(dp.name, proxy.name, msg=msg)
self.assertEqual(dp.value, proxy.value, msg=msg)
# also test things with .defer()
msg = "QuerySet.defer() return bogus results with proxy models"
dp = Proxy.objects.defer("name", "text", "value").get(pk=proxy.pk)
self.assertEqual(dp.name, proxy.name, msg=msg)
self.assertEqual(dp.value, proxy.value, msg=msg)
def test_resolve_columns(self):
ResolveThis.objects.create(num=5.0, name="Foobar")
qs = ResolveThis.objects.defer("num")
self.assertEqual(1, qs.count())
self.assertEqual("Foobar", qs[0].name)
def test_reverse_one_to_one_relations(self):
# Refs #14694. Test reverse relations which are known unique (reverse
# side has o2ofield or unique FK) - the o2o case
item = Item.objects.create(name="first", value=42)
o2o = OneToOneItem.objects.create(item=item, name="second")
self.assertEqual(len(Item.objects.defer("one_to_one_item__name")), 1)
self.assertEqual(len(Item.objects.select_related("one_to_one_item")), 1)
self.assertEqual(
len(
Item.objects.select_related("one_to_one_item").defer(
"one_to_one_item__name"
)
),
1,
)
self.assertEqual(
len(Item.objects.select_related("one_to_one_item").defer("value")), 1
)
# Make sure that `only()` doesn't break when we pass in a unique relation,
# rather than a field on the relation.
self.assertEqual(len(Item.objects.only("one_to_one_item")), 1)
with self.assertNumQueries(1):
i = Item.objects.select_related("one_to_one_item")[0]
self.assertEqual(i.one_to_one_item.pk, o2o.pk)
self.assertEqual(i.one_to_one_item.name, "second")
with self.assertNumQueries(1):
i = Item.objects.select_related("one_to_one_item").defer(
"value", "one_to_one_item__name"
)[0]
self.assertEqual(i.one_to_one_item.pk, o2o.pk)
self.assertEqual(i.name, "first")
with self.assertNumQueries(1):
self.assertEqual(i.one_to_one_item.name, "second")
with self.assertNumQueries(1):
self.assertEqual(i.value, 42)
with self.assertNumQueries(1):
i = Item.objects.select_related("one_to_one_item").only(
"name", "one_to_one_item__item"
)[0]
self.assertEqual(i.one_to_one_item.pk, o2o.pk)
self.assertEqual(i.name, "first")
with self.assertNumQueries(1):
self.assertEqual(i.one_to_one_item.name, "second")
with self.assertNumQueries(1):
self.assertEqual(i.value, 42)
def test_defer_with_select_related(self):
item1 = Item.objects.create(name="first", value=47)
item2 = Item.objects.create(name="second", value=42)
simple = SimpleItem.objects.create(name="simple", value="23")
ItemAndSimpleItem.objects.create(item=item1, simple=simple)
obj = ItemAndSimpleItem.objects.defer("item").select_related("simple").get()
self.assertEqual(obj.item, item1)
self.assertEqual(obj.item_id, item1.id)
obj.item = item2
obj.save()
obj = ItemAndSimpleItem.objects.defer("item").select_related("simple").get()
self.assertEqual(obj.item, item2)
self.assertEqual(obj.item_id, item2.id)
def test_proxy_model_defer_with_select_related(self):
# Regression for #22050
item = Item.objects.create(name="first", value=47)
RelatedItem.objects.create(item=item)
# Defer fields with only()
obj = ProxyRelated.objects.select_related().only("item__name")[0]
with self.assertNumQueries(0):
self.assertEqual(obj.item.name, "first")
with self.assertNumQueries(1):
self.assertEqual(obj.item.value, 47)
def test_only_with_select_related(self):
# Test for #17485.
item = SimpleItem.objects.create(name="first", value=47)
feature = Feature.objects.create(item=item)
SpecialFeature.objects.create(feature=feature)
qs = Feature.objects.only("item__name").select_related("item")
self.assertEqual(len(qs), 1)
qs = SpecialFeature.objects.only("feature__item__name").select_related(
"feature__item"
)
self.assertEqual(len(qs), 1)
def test_defer_annotate_select_related(self):
location = Location.objects.create()
Request.objects.create(location=location)
self.assertIsInstance(
list(
Request.objects.annotate(Count("items"))
.select_related("profile", "location")
.only("profile", "location")
),
list,
)
self.assertIsInstance(
list(
Request.objects.annotate(Count("items"))
.select_related("profile", "location")
.only("profile__profile1", "location__location1")
),
list,
)
self.assertIsInstance(
list(
Request.objects.annotate(Count("items"))
.select_related("profile", "location")
.defer("request1", "request2", "request3", "request4")
),
list,
)
def test_common_model_different_mask(self):
child = Child.objects.create(name="Child", value=42)
second_child = Child.objects.create(name="Second", value=64)
Leaf.objects.create(child=child, second_child=second_child)
with self.assertNumQueries(1):
leaf = (
Leaf.objects.select_related("child", "second_child")
.defer("child__name", "second_child__value")
.get()
)
self.assertEqual(leaf.child, child)
self.assertEqual(leaf.second_child, second_child)
self.assertEqual(leaf.child.get_deferred_fields(), {"name"})
self.assertEqual(leaf.second_child.get_deferred_fields(), {"value"})
with self.assertNumQueries(0):
self.assertEqual(leaf.child.value, 42)
self.assertEqual(leaf.second_child.name, "Second")
with self.assertNumQueries(1):
self.assertEqual(leaf.child.name, "Child")
with self.assertNumQueries(1):
self.assertEqual(leaf.second_child.value, 64)
def test_defer_many_to_many_ignored(self):
location = Location.objects.create()
request = Request.objects.create(location=location)
with self.assertNumQueries(1):
self.assertEqual(Request.objects.defer("items").get(), request)
def test_only_many_to_many_ignored(self):
location = Location.objects.create()
request = Request.objects.create(location=location)
with self.assertNumQueries(1):
self.assertEqual(Request.objects.only("items").get(), request)
def test_defer_reverse_many_to_many_ignored(self):
location = Location.objects.create()
request = Request.objects.create(location=location)
item = Item.objects.create(value=1)
request.items.add(item)
with self.assertNumQueries(1):
self.assertEqual(Item.objects.defer("request").get(), item)
def test_only_reverse_many_to_many_ignored(self):
location = Location.objects.create()
request = Request.objects.create(location=location)
item = Item.objects.create(value=1)
request.items.add(item)
with self.assertNumQueries(1):
self.assertEqual(Item.objects.only("request").get(), item)
def test_self_referential_one_to_one(self):
first = Item.objects.create(name="first", value=1)
second = Item.objects.create(name="second", value=2, source=first)
with self.assertNumQueries(1):
deferred_first, deferred_second = (
Item.objects.select_related("source", "destination")
.only("name", "source__name", "destination__value")
.order_by("pk")
)
with self.assertNumQueries(0):
self.assertEqual(deferred_first.name, first.name)
self.assertEqual(deferred_second.name, second.name)
self.assertEqual(deferred_second.source.name, first.name)
self.assertEqual(deferred_first.destination.value, second.value)
with self.assertNumQueries(1):
self.assertEqual(deferred_first.value, first.value)
with self.assertNumQueries(1):
self.assertEqual(deferred_second.source.value, first.value)
with self.assertNumQueries(1):
self.assertEqual(deferred_first.destination.name, second.name)
class DeferDeletionSignalsTests(TestCase):
senders = [Item, Proxy]
@classmethod
def setUpTestData(cls):
cls.item_pk = Item.objects.create(value=1).pk
def setUp(self):
self.pre_delete_senders = []
self.post_delete_senders = []
for sender in self.senders:
models.signals.pre_delete.connect(self.pre_delete_receiver, sender)
self.addCleanup(
models.signals.pre_delete.disconnect, self.pre_delete_receiver, sender
)
models.signals.post_delete.connect(self.post_delete_receiver, sender)
self.addCleanup(
models.signals.post_delete.disconnect, self.post_delete_receiver, sender
)
def pre_delete_receiver(self, sender, **kwargs):
self.pre_delete_senders.append(sender)
def post_delete_receiver(self, sender, **kwargs):
self.post_delete_senders.append(sender)
def test_delete_defered_model(self):
Item.objects.only("value").get(pk=self.item_pk).delete()
self.assertEqual(self.pre_delete_senders, [Item])
self.assertEqual(self.post_delete_senders, [Item])
def test_delete_defered_proxy_model(self):
Proxy.objects.only("value").get(pk=self.item_pk).delete()
self.assertEqual(self.pre_delete_senders, [Proxy])
self.assertEqual(self.post_delete_senders, [Proxy])