django1/tests/get_object_or_404/tests.py

125 lines
4.6 KiB
Python

from django.db.models import Q
from django.http import Http404
from django.shortcuts import get_list_or_404, get_object_or_404
from django.test import TestCase
from .models import Article, Author
class GetObjectOr404Tests(TestCase):
def test_get_object_or_404(self):
a1 = Author.objects.create(name="Brave Sir Robin")
a2 = Author.objects.create(name="Patsy")
# No Articles yet, so we should get an Http404 error.
with self.assertRaises(Http404):
get_object_or_404(Article, title="Foo")
article = Article.objects.create(title="Run away!")
article.authors.set([a1, a2])
# get_object_or_404 can be passed a Model to query.
self.assertEqual(
get_object_or_404(Article, title__contains="Run"),
article
)
# We can also use the Article manager through an Author object.
self.assertEqual(
get_object_or_404(a1.article_set, title__contains="Run"),
article
)
# No articles containing "Camelot". This should raise an Http404 error.
with self.assertRaises(Http404):
get_object_or_404(a1.article_set, title__contains="Camelot")
# Custom managers can be used too.
self.assertEqual(
get_object_or_404(Article.by_a_sir, title="Run away!"),
article
)
# QuerySets can be used too.
self.assertEqual(
get_object_or_404(Article.objects.all(), title__contains="Run"),
article
)
# Just as when using a get() lookup, you will get an error if more than
# one object is returned.
with self.assertRaises(Author.MultipleObjectsReturned):
get_object_or_404(Author.objects.all())
# Using an empty QuerySet raises an Http404 error.
with self.assertRaises(Http404):
get_object_or_404(Article.objects.none(), title__contains="Run")
# get_list_or_404 can be used to get lists of objects
self.assertEqual(
get_list_or_404(a1.article_set, title__icontains="Run"),
[article]
)
# Http404 is returned if the list is empty.
with self.assertRaises(Http404):
get_list_or_404(a1.article_set, title__icontains="Shrubbery")
# Custom managers can be used too.
self.assertEqual(
get_list_or_404(Article.by_a_sir, title__icontains="Run"),
[article]
)
# QuerySets can be used too.
self.assertEqual(
get_list_or_404(Article.objects.all(), title__icontains="Run"),
[article]
)
# Q objects.
self.assertEqual(
get_object_or_404(
Article,
Q(title__startswith='Run') | Q(title__startswith='Walk'),
authors__name__contains='Brave',
),
article,
)
self.assertEqual(
get_list_or_404(
Article,
Q(title__startswith='Run') | Q(title__startswith='Walk'),
authors__name='Patsy',
),
[article],
)
def test_bad_class(self):
# Given an argument klass that is not a Model, Manager, or Queryset
# raises a helpful ValueError message
msg = "First argument to get_object_or_404() must be a Model, Manager, or QuerySet, not 'str'."
with self.assertRaisesMessage(ValueError, msg):
get_object_or_404("Article", title__icontains="Run")
class CustomClass:
pass
msg = "First argument to get_object_or_404() must be a Model, Manager, or QuerySet, not 'CustomClass'."
with self.assertRaisesMessage(ValueError, msg):
get_object_or_404(CustomClass, title__icontains="Run")
# Works for lists too
msg = "First argument to get_list_or_404() must be a Model, Manager, or QuerySet, not 'list'."
with self.assertRaisesMessage(ValueError, msg):
get_list_or_404([Article], title__icontains="Run")
def test_get_object_or_404_queryset_attribute_error(self):
"""AttributeError raised by QuerySet.get() isn't hidden."""
with self.assertRaisesMessage(AttributeError, 'AttributeErrorManager'):
get_object_or_404(Article.attribute_error_objects, id=42)
def test_get_list_or_404_queryset_attribute_error(self):
"""AttributeError raised by QuerySet.filter() isn't hidden."""
with self.assertRaisesMessage(AttributeError, 'AttributeErrorManager'):
get_list_or_404(Article.attribute_error_objects, title__icontains='Run')