Unit test to validate fixtures

tests.py

class FixturesTest(TestCase):

    def test_num_fixtures(self):
        """All fixtures on the project are tested"""
        apps = [app.replace('.', '/')
                for app in settings.INSTALLED_APPS if app.startswith('rh2')]
        fixtures = []
        for app in apps:
            fixture_dir = path.join(path.dirname(settings.PROJECT_ROOT),
                                    app,
                                    'fixtures')
            fixtures += glob.glob(fixture_dir + '/*.json')
        # If this test fails, it's because a fixture was added but the number
        # of tests here wasn't changed.
        # While you're at it, please add a test for the new fixture.
        self.assertEqual(len(fixtures), 7, "Did you add or remove a fixture "
                                           "without testing it and modifying "
                                           "this test?")

    def _load_fixture(self, app_name, fixture_name):
        """Load a fixture and return the error message if any"""
        stderr = StringIO()
        fixture = path.join('apps', app_name, 'fixtures', fixture_name)
        call_command('loaddata',
                     fixture,
                     verbosity=0,
                     interactive=False,
                     stderr=stderr)
        return stderr.getvalue()

    def test_load_fixtures(self):
        self.assertEqual(self._load_fixture('some_app', 'somefixture.json'), '')
        self.assertEqual(self._load_fixture('other_app', 'otherfixture.json'), '')
        # add a test for each fixture