Im writing some code which retrieves info about installed apps, especially defined models, and then does stuff based on that information, but Im having some problems writing a clean, nice unittest. Is there a way to emulate or add an app in unittests without have to run manage.py startproject, manage.py startapp in my testsfolder to have a test app available for unittests?
Sure, try this on for size:
from django.conf import settings
from django.core.management import call_command
from django.test.testcases import TestCase
from django.db.models import loading
class AppTestCase(TestCase):
'''
Adds apps specified in `self.apps` to `INSTALLED_APPS` and
performs a `syncdb` at runtime.
'''
apps = ()
_source_installed_apps = ()
def _pre_setup(self):
super(AppTestCase, self)._pre_setup()
if self.apps:
self._source_installed_apps = settings.INSTALLED_APPS
settings.INSTALLED_APPS = settings.INSTALLED_APPS + self.apps
loading.cache.loaded = False
call_command('syncdb', verbosity=0)
def _post_teardown(self):
super(AppTestCase, self)._post_teardown()
if self._source_installed_apps:
settings.INSTALLED_APPS = self._source_installed_apps
self._source_installed_apps = ()
loading.cache.loaded = False
Your test case would look something like this:
class SomeAppTestCase(AppTestCase):
apps = ('someapp',)
In case you were wondering why, I did an override of _pre_setup() and _post_teardown() so I don't have to bother with calling super() in setUp() and tearDown() in my final test case. Otherwise, this is what I pulled out of Django's test runner. I whipped it up and it worked, although I'm sure that, with closer inspection, you can further optimize it and even avoid calling syncdb every time if it won't conflict with future tests.
EDIT:
So I seem to have gotten out of my way, thinking you need to dynamically add new models. If you've created an app for testing purposes only, here's what you can do to have it discovered during your tests.
In your project directory, create a test.py file that will contain your test settings. It should look something like this:
from settings import *
# registers test app for discovery
INSTALLED_APPS += ('path.to.test.app',)
You can now run your tests with python manage.py test --settings=myproject.test and your app will be in the installed apps.
Related
Under my Django project there are a few apps and all of them have unit tests. One of them that I'm working right now is supposed to be included only in dev/stage environments, so I'm enabling it using a environment variable.
When this variable is present it is added to INSTALLED_APPS and it is working just fine, the problem is that Django is executing the tests for this app even when it is not in INSTALLED_APPS, and it fails with the following message:
ImportError: Failed to import test module: debug.tests.unit.test_services`
...(traceback information)...
RuntimeError: Model class debug.models.Email doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS.
When I define the app_label in the class Meta of models in this app the error is different, it says it can't find a table, I assume that this is because the app is not in INSTALLED_APPS, so it's migrations are not executed.
OperationalError: no such table: debug_email
I'm not sure why Django executes the tests for all apps, but not it's migrations.
Am I missing something from Django configuration for tests?
https://docs.python.org/3/library/unittest.html#unittest.TestLoader.discover says:
If load_tests exists then discovery does not recurse into the package, load_tests is responsible for loading all tests in the package.
So in the lowest __init__.py in your app which you don't always want run:
from django.apps import apps
def load_tests(loader, tests, pattern):
from django.conf import settings
if apps.is_installed("your_dev_app"):
# Actually load the tests - thanks to #barney-szabolcs
return loader.discover(start_dir=dirname(abspath(__file__)), pattern=pattern)
You need to return the discovered tests in load_tests.
So, adding to #DaveLawrence's answer, the complete code is:
# your_dev_app/__init__.py
from django.apps import apps
from os.path import dirname, abspath
def load_tests(loader, tests, pattern):
"""
loads tests for your_dev_app if it is installed.
"""
from django.conf import settings
if apps.is_installed("your_dev_app"):
return loader.discover(start_dir=dirname(abspath(__file__)), pattern=pattern)
When you run:
python manage.py test
the command will look per default recursive for all files with the pattern test*.py in the working directory. It isn't affected by INSTALLED_APPS in settings.py.
You can specify a certain app to test it:
python manage.py test app_label
or specify a path:
python manage.py test myapp/tests
If you want to exclude some tests you can tag them and use the option --exclude-tag.
Run python manage.py test --help to get information on all options.
The official documentation gives a lot of information on the different possibilities how to run the tests.
EDIT:
If you have apps that are required only in the development environment, but not in the production, you could split your settings.py. One possible solution would be to outsource all development settings into a file local_settings.py and exclude it from versioning or from the production branch, i.e. don't push it in the production environment.
local_settings.py
DEBUG = True
INSTALLED_APPS += (
# Django Debug Toolbar would be for example
# used only in development
'debug_toolbar',
'your dev app',
)
settings.py
try:
from .local_settings import *
except ImportError:
pass
I'm writing a reusable django app and I need to ensure that its models are only sync'ed when the app is in test mode. I've tried to use a custom DjangoTestRunner, but I found no examples of how to do that (the documentation only shows how to define a custom test runner).
So, does anybody have an idea of how to do it?
EDIT
Here's how I'm doing it:
#in settings.py
import sys
TEST = 'test' in sys.argv
Hope it helps.
I think the answer provided here https://stackoverflow.com/a/7651002/465673 is a much cleaner way of doing it:
Put this in your settings.py:
import sys
TESTING = sys.argv[1:2] == ['test']
The selected answer is a massive hack. :)
A less-massive hack would be to create your own TestSuiteRunner subclass and change a setting or do whatever else you need to for the rest of your application. You specify the test runner in your settings:
TEST_RUNNER = 'your.project.MyTestSuiteRunner'
In general, you don't want to do this, but it works if you absolutely need it.
from django.conf import settings
from django.test.simple import DjangoTestSuiteRunner
class MyTestSuiteRunner(DjangoTestSuiteRunner):
def __init__(self, *args, **kwargs):
settings.IM_IN_TEST_MODE = True
super(MyTestSuiteRunner, self).__init__(*args, **kwargs)
NOTE: As of Django 1.8, DjangoTestSuiteRunner has been deprecated.
You should use DiscoverRunner instead:
from django.conf import settings
from django.test.runner import DiscoverRunner
class MyTestSuiteRunner(DiscoverRunner):
def __init__(self, *args, **kwargs):
settings.IM_IN_TEST_MODE = True
super(MyTestSuiteRunner, self).__init__(*args, **kwargs)
Not quite sure about your use case but one way I've seen to detect when the test suite is running is to check if django.core.mail has a outbox attribute such as:
from django.core import mail
if hasattr(mail, 'outbox'):
# We are in test mode!
pass
else:
# Not in test mode...
pass
This attributed is added by the Django test runner in setup_test_environment and removed in teardown_test_environment. You can check the source here: https://code.djangoproject.com/browser/django/trunk/django/test/utils.py
Edit: If you want models defined for testing only then you should check out Django ticket #7835 in particular comment #24 part of which is given below:
Apparently you can simply define models directly in your tests.py.
Syncdb never imports tests.py, so those models won't get synced to the
normal db, but they will get synced to the test database, and can be
used in tests.
I'm using settings.py overrides. I have a global settings.py, which contains most stuff, and then I have overrides for it. Each settings file starts with:
from myproject.settings import settings
and then goes on to override some of the settings.
prod_settings.py - Production settings (e.g. overrides DEBUG=False)
dev_settings.py - Development settings (e.g. more logging)
test_settings.py
And then I can define UNIT_TESTS=False in the base settings.py, and override it to UNIT_TESTS=True in test_settings.py.
Then whenever I run a command, I need to decide which settings to run against (e.g. DJANGO_SETTINGS_MODULE=myproject.test_settings ./manage.py test). I like that clarity.
Well, you can just simply use environment variables in this way:
export MYAPP_TEST=1 && python manage.py test
then in your settings.py file:
import os
TEST = os.environ.get('MYAPP_TEST')
if TEST:
# Do something
Although there are lots of good answers on this page, I think there is also another way to check if your project is in the test mode or not (if in some cases you couldn't use sys.argv[1:2] == ["test"]).
As you all may know DATABASE name will change to something like "test_*" (DATABASE default name will be prefixed with test) when you are in the test mode (or you can simply print it out to find your database name when you are running tests). Since I used pytest in one of my projects, I couldn't use
sys.argv[1:2] == ["test"]
because this argument wasn't there. So I simply used this one as my shortcut to check if I'm in the test environment or not (you know that your DATABASE name prefixed with test and if not just change test to your prefixed part of DATABASE name):
1) Any places other than settings module
from django.conf import settings
TESTING_MODE = "test" in settings.DATABASES["default"]["NAME"]
2) Inside the settings module
TESTING_MODE = "test" in DATABASES["default"]["NAME"]
or
TESTING_MODE = DATABASES["default"]["NAME"].startswith("test") # for more strict checks
And if this solution is doable, you don't even need to import sys for checking this mode inside your settings.py module.
I've been using Django class based settings. I use the 'switcher' from the package and load a different config/class for testing=True:
switcher.register(TestingSettings, testing=True)
In my configuration, I have a BaseSettings, ProductionSettings, DevelopmentSettings, TestingSettings, etc. They subclass off of each other as needed. In BaseSettings I have IS_TESTING=False, and then in TestingSettings I set it to True.
It works well if you keep your class inheritance clean. But I find it works better than the import * method Django developers usually use.
How can I detect whether a view is being called in a test environment (e.g., from manage.py test)?
#pseudo_code
def my_view(request):
if not request.is_secure() and not TEST_ENVIRONMENT:
return HttpResponseForbidden()
Put this in your settings.py:
import sys
TESTING = len(sys.argv) > 1 and sys.argv[1] == 'test'
This tests whether the second commandline argument (after ./manage.py) was test. Then you can access this variable from other modules, like so:
from django.conf import settings
if settings.TESTING:
...
There are good reasons to do this: suppose you're accessing some backend service, other than Django's models and DB connections. Then you might need to know when to call the production service vs. the test service.
Create your own TestSuiteRunner subclass and change a setting or do whatever else you need to for the rest of your application. You specify the test runner in your settings:
TEST_RUNNER = 'your.project.MyTestSuiteRunner'
In general, you don't want to do this, but it works if you absolutely need it.
from django.conf import settings
from django.test.simple import DjangoTestSuiteRunner
class MyTestSuiteRunner(DjangoTestSuiteRunner):
def __init__(self, *args, **kwargs):
settings.IM_IN_TEST_MODE = True
super(MyTestSuiteRunner, self).__init__(*args, **kwargs)
Just look at request.META['SERVER_NAME']
def my_view(request):
if request.META['SERVER_NAME'] == "testserver":
print "This is test environment!"
There's also a way to temporarily overwrite settings in a unit test in Django. This might be a easier/cleaner solution for certain cases.
You can do this inside a test:
with self.settings(MY_SETTING='my_value'):
# test code
Or add it as a decorator on the test method:
#override_settings(MY_SETTING='my_value')
def test_my_test(self):
# test code
You can also set the decorator for the whole test case class:
#override_settings(MY_SETTING='my_value')
class MyTestCase(TestCase):
# test methods
For more info check the Django docs: https://docs.djangoproject.com/en/1.11/topics/testing/tools/#django.test.override_settings
I think the best approach is to run your tests using their own settings file (i.e. settings/tests.py). That file can look like this (the first line imports settings from a local.py settings file):
from local import *
TEST_MODE = True
Then do ducktyping to check if you are in test mode.
try:
if settings.TEST_MODE:
print 'foo'
except AttributeError:
pass
If you are multiple settings file for different environment, all you need to do is to create one settings file for testing.
For instance, your setting files are:
your_project/
|_ settings/
|_ __init__.py
|_ base.py <-- your original settings
|_ testing.py <-- for testing only
In your testing.py, add a TESTING flag:
from .base import *
TESTING = True
In your application, you can access settings.TESTING to check if you're in testing environment.
To run tests, use:
python manage.py test --settings your_project.settings.testing
While there's no official way to see whether we're in a test environment, django actually leaves some clues for us.
By default Django’s test runner automatically redirects all Django-sent email to a dummy outbox. This is accomplished by replacing EMAIL_BACKEND in a function called setup_test_environment, which in turn is called by a method of DiscoverRunner. So, we can check whether settings.EMAIL_BACKEND is set to 'django.core.mail.backends.locmem.EmailBackend'. That mean we're in a test environment.
A less hacky solution would be following the devs lead by adding our own setting by subclassing DisoverRunner and then overriding setup_test_environment method.
Piggybacking off of #Tobia's answer, I think it is better implemented in settings.py like this:
import sys
try:
TESTING = 'test' == sys.argv[1]
except IndexError:
TESTING = False
This will prevent it from catching things like ./manage.py loaddata test.json or ./manage.py i_am_not_running_a_test
I wanted to exclude some data migrations from being run in tests, and came up with this solution on a Django 3.2 project:
class Migration(migrations.Migration):
def apply(self, project_state, schema_editor, collect_sql=False):
import inspect
if 'create_test_db' in [i.function for i in inspect.stack()]:
return project_state
else:
return super().apply(project_state, schema_editor, collect_sql=collect_sql)
I haven't seen this suggested elsewhere, and for my purposes it's pretty clean. Of course, it might break if Django changes the name of the create_test_db method (or the return value of the apply method) at some point in time, but modifying this to work should be reasonably simple, since it's likely that some method exists in the stack that doesn't exist during non-test migration runs.
I'm trying to start writing unit tests for django and I'm having some questions about fixtures:
I made a fixture of my whole project db (not certain application) and I want to load it for each test, because it looks like loading only the fixture for certain app won't be enough.
I'd like to have the fixture stored in /proj_folder/fixtures/proj_fixture.json.
I've set the FIXTURE_DIRS = ('/fixtures/',) in my settings.py.
Then in my testcase I'm trying
fixtures = ['proj_fixture.json']
but my fixtures don't load.
How can this be solved?
How to add the place for searching fixtures?
In general, is it ok to load the fixture for the whole test_db for each test in each app (if it's quite small)?
Thanks!
I've specified path relative to project root in the TestCase like so:
from django.test import TestCase
class MyTestCase(TestCase):
fixtures = ['/myapp/fixtures/dump.json',]
...
and it worked without using FIXTURE_DIRS
Good practice is using PROJECT_ROOT variable in your settings.py:
import os.path
PROJECT_ROOT = os.path.dirname(os.path.realpath(__file__))
FIXTURE_DIRS = (os.path.join(PROJECT_ROOT, 'fixtures'),)
Do you really have a folder /fixtures/ on your hard disk?
You probably intended to use:
FIXTURE_DIRS = ('/path/to/proj_folder/fixtures/',)
Instead of creating fixures folder and placing fixtures in them (in every app), a better and neater way to handle this would be to put all fixtures in one folder at the project level and load them.
from django.core.management import call_command
class TestMachin(TestCase):
def setUp(self):
# Load fixtures
call_command('loaddata', 'fixtures/myfixture', verbosity=0)
Invoking call_command is equivalent to running :
manage.py loaddata /path/to/fixtures
Saying you have a project named hello_django with api app.
Following are steps to create fixtures for it:
Optional step: create fixture file from database: python manage.py dumpdata --format=json > api/fixtures/testdata.json
Create test directory: api/tests
Create empty file __init__.py in api/tests
Create test file: test_fixtures.py
from django.test import TestCase
class FixturesTestCase(TestCase):
fixtures = ['api/api/fixtures/testdata.json']
def test_it(self):
# implement your test here
Run the test to load fixtures into the database: python manage.py test api.tests
I did this and I didn't have to give a path reference, the fixture file name was enough for me.
class SomeTest(TestCase):
fixtures = ('myfixture.json',)
You have two options, depending on whether you have a fixture, or you have a set of Python code to populate the data.
For fixtures, use cls.fixtures, like shown in an answer to this question,
class MyTestCase(django.test.TestCase):
fixtures = ['/myapp/fixtures/dump.json',]
For Python, use cls.setUpTestData:
class MyTestCase(django.test.TestCase):
#classmethod
def setUpTestData(cls):
cls.create_fixture() # create_fixture is a custom function
setUpTestData is called by the TestCase.setUpClass.
You can use both, in which case fixtures is loaded first because setUpTestData is called after loading the fixtures.
You need to import from django.test import TestCase and NOT from unittest import TestCase. That fixed the problem for me.
If you have overridden setUpClass method, make sure you call super().setUpClass() method as the first line in the method. The code to load fixtures is in TestCase class.
Is there any simple mechanism for overriding Django settings for a unit test? I have a manager on one of my models that returns a specific number of the latest objects. The number of objects it returns is defined by a NUM_LATEST setting.
This has the potential to make my tests fail if someone were to change the setting. How can I override the settings on setUp() and subsequently restore them on tearDown()? If that isn't possible, is there some way I can monkey patch the method or mock the settings?
EDIT: Here is my manager code:
class LatestManager(models.Manager):
"""
Returns a specific number of the most recent public Articles as defined by
the NEWS_LATEST_MAX setting.
"""
def get_query_set(self):
num_latest = getattr(settings, 'NEWS_NUM_LATEST', 10)
return super(LatestManager, self).get_query_set().filter(is_public=True)[:num_latest]
The manager uses settings.NEWS_LATEST_MAX to slice the queryset. The getattr() is simply used to provide a default should the setting not exist.
EDIT: This answer applies if you want to change settings for a small number of specific tests.
Since Django 1.4, there are ways to override settings during tests:
https://docs.djangoproject.com/en/stable/topics/testing/tools/#overriding-settings
TestCase will have a self.settings context manager, and there will also be an #override_settings decorator that can be applied to either a test method or a whole TestCase subclass.
These features did not exist yet in Django 1.3.
If you want to change settings for all your tests, you'll want to create a separate settings file for test, which can load and override settings from your main settings file. There are several good approaches to this in the other answers; I have seen successful variations on both hspander's and dmitrii's approaches.
You can do anything you like to the UnitTest subclass, including setting and reading instance properties:
from django.conf import settings
class MyTest(unittest.TestCase):
def setUp(self):
self.old_setting = settings.NUM_LATEST
settings.NUM_LATEST = 5 # value tested against in the TestCase
def tearDown(self):
settings.NUM_LATEST = self.old_setting
Since the django test cases run single-threaded, however, I'm curious about what else may be modifying the NUM_LATEST value? If that "something else" is triggered by your test routine, then I'm not sure any amount of monkey patching will save the test without invalidating the veracity of the tests itself.
You can pass --settings option when running tests
python manage.py test --settings=mysite.settings_local
Although overriding settings configuration on runtime might help, in my opinion you should create a separate file for testing. This saves lot of configuration for testing and this would ensure that you never end up doing something irreversible (like cleaning staging database).
Say your testing file exists in 'my_project/test_settings.py', add
settings = 'my_project.test_settings' if 'test' in sys.argv else 'my_project.settings'
in your manage.py. This will ensure that when you run python manage.py test you use test_settings only. If you are using some other testing client like pytest, you could as easily add this to pytest.ini
Update: the solution below is only needed on Django 1.3.x and earlier. For >1.4 see slinkp's answer.
If you change settings frequently in your tests and use Python ≥2.5, this is also handy:
from contextlib import contextmanager
class SettingDoesNotExist:
pass
#contextmanager
def patch_settings(**kwargs):
from django.conf import settings
old_settings = []
for key, new_value in kwargs.items():
old_value = getattr(settings, key, SettingDoesNotExist)
old_settings.append((key, old_value))
setattr(settings, key, new_value)
yield
for key, old_value in old_settings:
if old_value is SettingDoesNotExist:
delattr(settings, key)
else:
setattr(settings, key, old_value)
Then you can do:
with patch_settings(MY_SETTING='my value', OTHER_SETTING='other value'):
do_my_tests()
You can override setting even for a single test function.
from django.test import TestCase, override_settings
class SomeTestCase(TestCase):
#override_settings(SOME_SETTING="some_value")
def test_some_function():
or you can override setting for each function in class.
#override_settings(SOME_SETTING="some_value")
class SomeTestCase(TestCase):
def test_some_function():
#override_settings is great if you don't have many differences between your production and testing environment configurations.
In other case you'd better just have different settings files. In this case your project will look like this:
your_project
your_app
...
settings
__init__.py
base.py
dev.py
test.py
production.py
manage.py
So you need to have your most of your settings in base.py and then in other files you need to import all everything from there, and override some options. Here's what your test.py file will look like:
from .base import *
DEBUG = False
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': 'app_db_test'
}
}
PASSWORD_HASHERS = (
'django.contrib.auth.hashers.MD5PasswordHasher',
)
LOGGING = {}
And then you either need to specify --settings option as in #MicroPyramid answer, or specify DJANGO_SETTINGS_MODULE environment variable and then you can run your tests:
export DJANGO_SETTINGS_MODULE=settings.test
python manage.py test
For pytest users.
The biggest issue is:
override_settings doesn't work with pytest.
Subclassing Django's TestCase will make it work but then you can't use pytest fixtures.
The solution is to use the settings fixture documented here.
Example
def test_with_specific_settings(settings):
settings.DEBUG = False
settings.MIDDLEWARE = []
..
And in case you need to update multiple fields
def override_settings(settings, kwargs):
for k, v in kwargs.items():
setattr(settings, k, v)
new_settings = dict(
DEBUG=True,
INSTALLED_APPS=[],
)
def test_with_specific_settings(settings):
override_settings(settings, new_settings)
I created a new settings_test.py file which would import everything from settings.py file and modify whatever is different for testing purpose.
In my case I wanted to use a different cloud storage bucket when testing.
settings_test.py:
from project1.settings import *
import os
CLOUD_STORAGE_BUCKET = 'bucket_name_for_testing'
manage.py:
def main():
# use seperate settings.py for tests
if 'test' in sys.argv:
print('using settings_test.py')
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'project1.settings_test')
else:
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'project1.settings')
try:
from django.core.management import execute_from_command_line
except ImportError as exc:
raise ImportError(
"Couldn't import Django. Are you sure it's installed and "
"available on your PYTHONPATH environment variable? Did you "
"forget to activate a virtual environment?"
) from exc
execute_from_command_line(sys.argv)
Found this while trying to fix some doctests... For completeness I want to mention that if you're going to modify the settings when using doctests, you should do it before importing anything else...
>>> from django.conf import settings
>>> settings.SOME_SETTING = 20
>>> # Your other imports
>>> from django.core.paginator import Paginator
>>> # etc
I'm using pytest.
I managed to solve this the following way:
import django
import app.setting
import modules.that.use.setting
# do some stuff with default setting
setting.VALUE = "some value"
django.setup()
import importlib
importlib.reload(app.settings)
importlib.reload(modules.that.use.setting)
# do some stuff with settings new value
You can override settings in test in this way:
from django.test import TestCase, override_settings
test_settings = override_settings(
DEFAULT_FILE_STORAGE='django.core.files.storage.FileSystemStorage',
PASSWORD_HASHERS=(
'django.contrib.auth.hashers.UnsaltedMD5PasswordHasher',
)
)
#test_settings
class SomeTestCase(TestCase):
"""Your test cases in this class"""
And if you need these same settings in another file you can just directly import test_settings.
If you have multiple test files placed in a subdirectory (python package), you can override settings for all these files based on condition of presence of 'test' string in sys.argv
app
tests
__init__.py
test_forms.py
test_models.py
__init__.py:
import sys
from project import settings
if 'test' in sys.argv:
NEW_SETTINGS = {
'setting_name': value,
'another_setting_name': another_value
}
settings.__dict__.update(NEW_SETTINGS)
Not the best approach. Used it to change Celery broker from Redis to Memory.
One setting for all tests in a testCase
class TestSomthing(TestCase):
def setUp(self, **kwargs):
with self.settings(SETTING_BAR={ALLOW_FOO=True})
yield
override one setting in the testCase
from django.test import override_settings
#override_settings(SETTING_BAR={ALLOW_FOO=False})
def i_need_other_setting(self):
...
Important
Even though you are overriding these settings this will not apply to settings that your server initialize stuff with because it is already initialized, to do that you will need to start django with another setting module.