Add unitests to a Django application

Suppose you have written a Django app and obviously you want to test it, the filesystem structure is something like the following:

.
├── my_django_app
│   ├── __init__.py
│   ├── models.py
│   ├── tests.py
└── runtests.py

where models.py contains something like this

from django.db import models

class A(models.Model):
    name = models.CharField(max_length=100)

and with very simple test module tests.py:

from django.test import TestCase
from .models import A


class Test(TestCase):
    def setUp(self):
        self.a = A(name='kebab')
        self.a.save()

    def test_model(self):
        self.assertEqual(self.a.name, 'kebab')

The magic happens with runtests.py that sets all the necessary in order to run all the tests:

from __future__ import absolute_import

import sys

from django.conf import settings
from django.core import management

APP_NAME = 'my_django_app'


def main():
    settings.configure(
        DATABASES = {
            'default': {
                'ENGINE': 'django.db.backends.sqlite3',
            }
        },
        INSTALLED_APPS = ( # These apps depend on what your app need
            'django.contrib.auth',
            'django.contrib.contenttypes',
            APP_NAME,
        ),
        TEMPLATE_CONTEXT_PROCESSORS = (
            'django.contrib.auth.context_processors.auth',
            'django.core.context_processors.debug',
            'django.core.context_processors.i18n',
            'django.core.context_processors.media',
            'django.core.context_processors.request',
            'django.core.context_processors.static',
            'django.core.context_processors.tz',
            'django.contrib.messages.context_processors.messages'
        ),
        ROOT_URLCONF = '%s.tests.urls' % APP_NAME,
        STATIC_URL = '/static/',
    )

    import django
    django.setup()
    management.execute_from_command_line(['', 'test', APP_NAME,])
    sys.exit()

if __name__ == '__main__':
    main()

Now you can launch the test without a complete Django project with a simple

$ python runtests.py
Creating test database for alias 'default'...
.
----------------------------------------------------------------------
Ran 1 test in 0.001s

OK
Destroying test database for alias 'default'...

This is only an example, inspired from other projects like dj-stripe. If you want really to wrote a Django app use cookiecutter-djangopackage that includes an updated version of this configuration and much more.