Python: Mock side_effect on object attribute
It's worth noting that there is now the PropertyMock
class:
>>> m = MagicMock()
>>> p = PropertyMock(side_effect=ValueError)
>>> type(m).foo = p
>>> m.foo
Traceback (most recent call last):
....
ValueError
That example was taken from the official site.
You can also try to patch the related field using a PropertyMock as new_callable argument.
Example:
from unittest import TestCase
import mock
from django import models
from django.core.exceptions import ObjectDoesNotExist
class Foo(models.Model):
# ...
@property
def has_pending_related(self):
try:
return self.related_field.is_pending
except ObjectDoesNotExist:
return False
class FooTestCase(TestCase):
# ...
@mock.patch.object(Foo, 'related_field', new_callable=mock.PropertyMock)
def test_pending_related(self, related_field):
related_field.side_effect = ObjectDoesNotExist
foo = Foo()
self.assertFalse(foo.has_pending_related)