Django’s build-in testing framework is extremely handy. As long as you use the ORM with a supported data store, a test database is used for the duration of the tests and is cleaned up in between unit tests. There is no need for elaborate mocking – something I had grown accustom to in .NET.

Here is a quick sample, edited for brevity:

$ ./manage.py test appname -v 2

Creating test database for alias 'default' ('test_projectname')…
Syncing...
Creating tables ...
test_first (projectname.test.SampleTestClass) ... ok
test_second (projectname.test.SampleTestClass) ... ok
test_third (projectname.test.SampleTestClass) ... ok
Ran 3 tests in 1.260s
OK
Destroying test database for alias 'default' ('test_projectname')…

But if you are using some external source of data, it is necessary to create a mock or some fake environment (as Django does).

Haystack is a handy library that abstracts out the details of various search engines. You get some powerful features build into something like Elasticsearch – high availability, full text search, spelling correct, more like this, etc – in some functions and data structures familiar to Django using developers.

But if you are integration testing, the tests are calling your views directly and your views are updating or retrieving data from an external search engine, you are going to potentially have a bad time. Stuff will be persisted between unit tests and your results will be likely be inconsistent.

The solution is pretty simple actually. Fire up a new index, override the settings such that the new index is the target for the Haystack calls for the duration of tests, and clear the index between tests.

TEST_INDEX = {
    'default': {
        'ENGINE': 'haystack.backends.elasticsearch_backend.ElasticsearchSearchEngine',
        'URL': 'http://127.0.0.1:9200/',
        'TIMEOUT': 60 * 10,
        'INDEX_NAME': 'test_index',
    },
}


@override_settings(HAYSTACK_CONNECTIONS=TEST_INDEX)
class BaseTestCase(TestCase):

    def setUp(self):
        haystack.connections.reload('default')
        super(BaseTestCase, self).setUp()

    def tearDown(self):
        call_command('clear_index', interactive=False, verbosity=0)

GIST here