- All the goodness of nose in your Django tests
- Fast fixture bundling, an optional feature which speeds up your fixture-based tests by a factor of 4
- Reuse of previously created test DBs, saving setup time
You can get django-nose from PyPI with...
pip install django-nose
The development version can be installed with...
pip install -e git://github.com/jbalogh/django-nose.git#egg=django-nose
Since django-nose extends Django's built-in test command, you should add it to your INSTALLED_APPS in settings.py:
INSTALLED_APPS = ( ... 'django_nose', ... )
Then set TEST_RUNNER in settings.py:
TEST_RUNNER = 'django_nose.NoseTestSuiteRunner'
The day-to-day use of django-nose is mostly transparent; just run ./manage.py test as usual.
See ./manage.py help test for all the options nose provides, and look to the nose docs for more help with nose.
You can save several seconds at the beginning and end of your test suite by reusing the test database from the last run. To do this, set the environment variable REUSE_DB to 1:
REUSE_DB=1 ./manage.py test
The one new wrinkle is that, whenever your DB schema changes, you should leave the flag off the next time you run tests. This will cue the test runner to reinitialize the test database.
django-nose includes a nose plugin which drastically speeds up your tests by eliminating redundant setup of Django test fixtures. To use it...
- Subclass django_nose.FastFixtureTestCase instead of django.test.TestCase. (I like to import it as TestCase in my project's tests/__init__.py and then import it from there into my actual tests. Then it's easy to sub the base class in an out.)
- Activate the plugin by passing the --with-fixture-bundling option to ./manage.py test.
The fixture bundler reorders your test classes so that ones with identical sets of fixtures run adjacently. It then advises the first of each series to load the fixtures once for all of them (and the remaining ones not to bother). It also advises the last to tear them down. Depending on the size and repetition of your fixtures, you can expect a 25% to 50% speed increase.
Incidentally, the author prefers to avoid Django fixtures, as they encourage irrelevant coupling between tests and make tests harder to comprehend and modify. For future tests, it is better to use the "model maker" pattern, creating DB objects programmatically. This way, tests avoid setup they don't need, and there is a clearer tie between a test and the exact state it requires. The fixture bundler is intended to make existing tests, which have already committed to fixtures, more tolerable.
If using --with-fixture-bundling causes test failures, it likely indicates an order dependency between some of your tests. Here are the most frequent sources of state leakage we have encountered:
- Locale activation, which is maintained in a threadlocal variable. Be sure to reset your locale selection between tests.
- memcached contents. Be sure to flush between tests. Many test superclasses do this automatically.
It's also possible that you have post_save signal handlers which create additional database rows while loading the fixtures. FastFixtureTestCase isn't yet smart enough to notice this and clean up after it, so you'll have to go back to plain old TestCase for now.
In some unusual cases, it is desirable to exempt a test class from fixture bundling, forcing it to set up and tear down its fixtures at the class boundaries. For example, we might have a TestCase subclass which sets up some state outside the DB in setUpClass and tears it down in tearDownClass, and it might not be possible to adapt those routines to heed the advice of the fixture bundler. In such a case, simply set the exempt_from_fixture_bundling attribute of the test class to True.
South installs its own test command that turns off migrations during testing. Make sure that django-nose comes after south in INSTALLED_APPS so that django_nose's test command is used.
To always set the same command line options you can use a nose.cfg or setup.cfg (as usual) or you can specify them in settings.py like this:
NOSE_ARGS = ['--failed', '--stop']
If you need to make custom plugins, you can define each plugin class somewhere within your app and load them from settings.py like this:
NOSE_PLUGINS = [ 'yourapp.tests.plugins.SystematicDysfunctioner', # ... ]
Just like middleware or anything else, each string must be a dot-separated, importable path to an actual class. Each plugin class will be instantiated and added to the Nose test runner.
Django 1.2 switches to a class-based test runner. To use django-nose with Django 1.2, change your TEST_RUNNER from django_nose.run_tests to django_nose.NoseTestSuiteRunner.
django_nose.run_tests will continue to work in Django 1.2, but will raise a warning. In Django 1.3 it will stop working.
If you were using django_nose.run_gis_tests, you should also switch to django_nose.NoseTestSuiteRunner and use one of the spatial backends in your DATABASES settings.
If you want to use django-nose with Django 1.1, use https://github.com/jbalogh/django-nose/tree/django-1.1 or http://pypi.python.org/pypi/django-nose/0.0.3.