1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142
|
from django.test import TestCase
from .models import Article, Car, Driver, Reporter
class ManyToOneNullTests(TestCase):
@classmethod
def setUpTestData(cls):
# Create a Reporter.
cls.r = Reporter(name='John Smith')
cls.r.save()
# Create an Article.
cls.a = Article(headline='First', reporter=cls.r)
cls.a.save()
# Create an Article via the Reporter object.
cls.a2 = cls.r.article_set.create(headline='Second')
# Create an Article with no Reporter by passing "reporter=None".
cls.a3 = Article(headline='Third', reporter=None)
cls.a3.save()
# Create another article and reporter
cls.r2 = Reporter(name='Paul Jones')
cls.r2.save()
cls.a4 = cls.r2.article_set.create(headline='Fourth')
def test_get_related(self):
self.assertEqual(self.a.reporter.id, self.r.id)
# Article objects have access to their related Reporter objects.
r = self.a.reporter
self.assertEqual(r.id, self.r.id)
def test_created_via_related_set(self):
self.assertEqual(self.a2.reporter.id, self.r.id)
def test_related_set(self):
# Reporter objects have access to their related Article objects.
self.assertSequenceEqual(self.r.article_set.all(), [self.a, self.a2])
self.assertSequenceEqual(self.r.article_set.filter(headline__startswith='Fir'), [self.a])
self.assertEqual(self.r.article_set.count(), 2)
def test_created_without_related(self):
self.assertIsNone(self.a3.reporter)
# Need to reget a3 to refresh the cache
a3 = Article.objects.get(pk=self.a3.pk)
with self.assertRaises(AttributeError):
getattr(a3.reporter, 'id')
# Accessing an article's 'reporter' attribute returns None
# if the reporter is set to None.
self.assertIsNone(a3.reporter)
# To retrieve the articles with no reporters set, use "reporter__isnull=True".
self.assertSequenceEqual(Article.objects.filter(reporter__isnull=True), [self.a3])
# We can achieve the same thing by filtering for the case where the
# reporter is None.
self.assertSequenceEqual(Article.objects.filter(reporter=None), [self.a3])
# Set the reporter for the Third article
self.assertSequenceEqual(self.r.article_set.all(), [self.a, self.a2])
self.r.article_set.add(a3)
self.assertSequenceEqual(
self.r.article_set.all(),
[self.a, self.a2, self.a3],
)
# Remove an article from the set, and check that it was removed.
self.r.article_set.remove(a3)
self.assertSequenceEqual(self.r.article_set.all(), [self.a, self.a2])
self.assertSequenceEqual(Article.objects.filter(reporter__isnull=True), [self.a3])
def test_remove_from_wrong_set(self):
self.assertSequenceEqual(self.r2.article_set.all(), [self.a4])
# Try to remove a4 from a set it does not belong to
with self.assertRaises(Reporter.DoesNotExist):
self.r.article_set.remove(self.a4)
self.assertSequenceEqual(self.r2.article_set.all(), [self.a4])
def test_set(self):
# Use manager.set() to allocate ForeignKey. Null is legal, so existing
# members of the set that are not in the assignment set are set to null.
self.r2.article_set.set([self.a2, self.a3])
self.assertSequenceEqual(self.r2.article_set.all(), [self.a2, self.a3])
# Use manager.set(clear=True)
self.r2.article_set.set([self.a3, self.a4], clear=True)
self.assertSequenceEqual(self.r2.article_set.all(), [self.a4, self.a3])
# Clear the rest of the set
self.r2.article_set.set([])
self.assertSequenceEqual(self.r2.article_set.all(), [])
self.assertSequenceEqual(
Article.objects.filter(reporter__isnull=True),
[self.a4, self.a2, self.a3],
)
def test_set_clear_non_bulk(self):
# 2 queries for clear(), 1 for add(), and 1 to select objects.
with self.assertNumQueries(4):
self.r.article_set.set([self.a], bulk=False, clear=True)
def test_assign_clear_related_set(self):
# Use descriptor assignment to allocate ForeignKey. Null is legal, so
# existing members of the set that are not in the assignment set are
# set to null.
self.r2.article_set.set([self.a2, self.a3])
self.assertSequenceEqual(self.r2.article_set.all(), [self.a2, self.a3])
# Clear the rest of the set
self.r.article_set.clear()
self.assertSequenceEqual(self.r.article_set.all(), [])
self.assertSequenceEqual(
Article.objects.filter(reporter__isnull=True),
[self.a, self.a4],
)
def test_assign_with_queryset(self):
# Querysets used in reverse FK assignments are pre-evaluated
# so their value isn't affected by the clearing operation in
# RelatedManager.set() (#19816).
self.r2.article_set.set([self.a2, self.a3])
qs = self.r2.article_set.filter(headline="Second")
self.r2.article_set.set(qs)
self.assertEqual(1, self.r2.article_set.count())
self.assertEqual(1, qs.count())
def test_add_efficiency(self):
r = Reporter.objects.create()
articles = []
for _ in range(3):
articles.append(Article.objects.create())
with self.assertNumQueries(1):
r.article_set.add(*articles)
self.assertEqual(r.article_set.count(), 3)
def test_clear_efficiency(self):
r = Reporter.objects.create()
for _ in range(3):
r.article_set.create()
with self.assertNumQueries(1):
r.article_set.clear()
self.assertEqual(r.article_set.count(), 0)
def test_related_null_to_field(self):
c1 = Car.objects.create()
d1 = Driver.objects.create()
self.assertIs(d1.car, None)
with self.assertNumQueries(0):
self.assertEqual(list(c1.drivers.all()), [])
|