Question

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?

Answer 1

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.