Django tests failing when run with all test cases - django

Question

I have a problem with tests. When I run some tests I launch separately, they pass. When all together then fail.
#mock.patch(
'apps.abstract.validators.years_range_is_not_future', new=fake_years_range_is_not_future
)
def test_create_building_with_validation_of_foundation_period(self):
self.c.login(username=self.user.username, password='111')
response = self.c.post(
'/en/api/buildings/',
data={
'name': "New Building",
'foundation_period': {
'lower': MIN_INT_VALUE,
'upper': MAX_INT_VALUE
},
'stream': {
'uuid': s_uuid(self.stream)
}
}
)
self.assertEqual(response.status_code, status.HTTP_201_CREATED)
I read about this problem here
why would a django test fail only when the full test suite is run?
and tried to patch the validator in the serializer file as shown here
#mock.patch(
'apps.buildings.api.serializers.years_range_is_not_future', new=fake_years_range_is_not_future
)
def test_create_building_with_validation_of_foundation_period(self):
..............................................................
but then I get an incomprehensible for me exception
Error
Traceback (most recent call last):
File "/usr/lib/python3.5/unittest/mock.py", line 1049, in _dot_lookup
return getattr(thing, comp)
AttributeError: module 'apps.buildings.api' has no attribute 'serializers'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.5/unittest/mock.py", line 1149, in patched
arg = patching.__enter__()
File "/usr/lib/python3.5/unittest/mock.py", line 1205, in __enter__
self.target = self.getter()
File "/usr/lib/python3.5/unittest/mock.py", line 1375, in <lambda>
getter = lambda: _importer(target)
File "/usr/lib/python3.5/unittest/mock.py", line 1062, in _importer
thing = _dot_lookup(thing, comp, import_path)
File "/usr/lib/python3.5/unittest/mock.py", line 1051, in _dot_lookup
__import__(import_path)
File "/home/env/project/apps/buildings/api/serializers.py", line 12, in <module>
from apps.communities.api.serializers import CommunityBriefSerializer
File "/home/env/project/apps/communities/api/serializers.py", line 297, in <module>
class CommunityOfficialRequestBuildingSerializer(BaseCommunityOfficialRequestSerializer):
File "/home/rp/env/project/apps/communities/api/serializers.py", line 299, in CommunityOfficialRequestBuildingSerializer
from apps.buildings.api.serializers import BuildingBriefSerializer
ImportError: cannot import name 'BuildingBriefSerializer'
help please understand what I'm doing wrong
project structure (__init__.py files not listed)
project
|__apps
|__communities
| |_api
| |_serializers.py
|
|__buildings
| |_api
| | |_serializers.py
| |
| |_tests
| |_test.py
|
|_abstract
|_validators.py

Answer 1

Seeing this,
Traceback (most recent call last):
File "/home/rp/env/project/apps/communities/api/serializers.py", line 299, in CommunityOfficialRequestBuildingSerializer
from apps.buildings.api.serializers import BuildingBriefSerializer
suggests that your import statement is inside a class or a def or some other statement.
Maybe the import statement is executed after you mocked apps.buildings.api.serializers. If you move this import to the top of the file, then BuildingBriefSerializer will probably become available before apps.buildings.api.serializers is mocked, and your tests will pass.
This would also explain why the tests run, when you run them individually.