django/tests/regressiontests/defer_regress/tests.py

165 lines
5.8 KiB
Python

from operator import attrgetter
from django.conf import settings
from django.contrib.contenttypes.models import ContentType
from django.contrib.sessions.backends.db import SessionStore
from django.db import connection
from django.db.models.loading import cache
from django.test import TestCase
from models import ResolveThis, Item, RelatedItem, Child, Leaf
class DeferRegressionTest(TestCase):
def assert_num_queries(self, n, func, *args, **kwargs):
old_DEBUG = settings.DEBUG
settings.DEBUG = True
starting_queries = len(connection.queries)
try:
func(*args, **kwargs)
finally:
settings.DEBUG = old_DEBUG
self.assertEqual(starting_queries + n, len(connection.queries))
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.
def test():
self.assertEqual(obj.name, "first")
self.assertEqual(obj.other_value, 0)
self.assert_num_queries(0, test)
def test():
self.assertEqual(obj.value, 42)
self.assert_num_queries(1, test)
def test():
self.assertEqual(obj.text, "xyzzy")
self.assert_num_queries(1, test)
def test():
self.assertEqual(obj.text, "xyzzy")
self.assert_num_queries(0, test)
# 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
# behaviour (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")
# Test for #12163 - Pickling error saving session with unsaved model
# instances.
SESSION_KEY = '2b1189a188b44ad18c35e1baac6ceead'
item = Item()
item._deferred = False
s = SessionStore(SESSION_KEY)
s.clear()
s["item"] = item
s.save()
s = SessionStore(SESSION_KEY)
s.modified = True
s.save()
i2 = s["item"]
self.assertFalse(i2._deferred)
# Regression for #11936 - loading.get_models should not return deferred
# models by default.
klasses = sorted(
cache.get_models(cache.get_app("defer_regress")),
key=lambda klass: klass.__name__
)
self.assertEqual(
klasses, [
Child,
Item,
Leaf,
RelatedItem,
ResolveThis,
]
)
klasses = sorted(
map(
attrgetter("__name__"),
cache.get_models(
cache.get_app("defer_regress"), include_deferred=True
),
)
)
self.assertEqual(
klasses, [
"Child",
"Child_Deferred_value",
"Item",
"Item_Deferred_name",
"Item_Deferred_name_other_value_text",
"Item_Deferred_name_other_value_value",
"Item_Deferred_other_value_text_value",
"Item_Deferred_text_value",
"Leaf",
"Leaf_Deferred_child_id_second_child_id_value",
"Leaf_Deferred_name_value",
"Leaf_Deferred_second_child_value",
"Leaf_Deferred_value",
"RelatedItem",
"RelatedItem_Deferred_",
"RelatedItem_Deferred_item_id",
"ResolveThis",
]
)
def test_resolve_columns(self):
rt = ResolveThis.objects.create(num=5.0, name='Foobar')
qs = ResolveThis.objects.defer('num')
self.assertEqual(1, qs.count())
self.assertEqual('Foobar', qs[0].name)