How to get django's unittest TestLoader to find and run my doctests?


In Django, my tests are a set of files inside my_django_app/tests/, which each contain a TestCase subclass, and which django automatically finds and runs.

I have a bunch of utility modules with simple doctests that I would like to be included with my test suite. I tried using doctest.DocTestSuite() to define test suites in my_django_app/tests/, but django’s test runner does not find the new tests in that module.

Is there a way I can create a TestCase class that calls my doctests, or somehow otherwise define a new tests/ module that would run these tests?

Asked By: Taylor Hughes



I solved this by creating a new module, my_django_app/tests/, that looks like:

import doctest
import unittest

# These are my modules that contain doctests:
from util import bitwise
from util import text
from util import urlutil

# unittest.TestLoader will call this when it finds this module:
def load_tests(*args, **kwargs):
  test_all_doctests = unittest.TestSuite()
  return test_all_doctests

Django uses the builtin unittest TestLoader, which, during test discovery, will call load_tests() on your test module. So we define load_tests which creates a test suite out of all of the doctests.

Answered By: Taylor Hughes

The automagic of Django unittests discovery looks for a load_tests function in your test_foo module and will run it. So you can use that to add your doctests to the test suite …

import doctest
import module_with_doctests

def load_tests(loader, tests, ignore):
    return tests

Also, due to a bug(?) in unittest your load_tests function won’t be run unless your test_foo module also defines a TestCase-derived class like so:

class DoNothingTest(TestCase):
    """Encourage Django unittests to run `load_tests()`."""
    def test_example(self):
Answered By: hobs
import django.test.runner

testsuite = django.test.runner.DiscoverRunner().build_suite()

but, as best I can tell, basic unittest discover produces the same collection

import unittest

testsuite = unittest.TestLoader().discover('.')


I did notice that unittest and django.test appear to use an internal attribute TestCase._testMethodName differently, in unittest, this is the testcase module+class namespace, in django, this appeared to be a random testcase method name, with the module and class being attributes of self.__module__. probably try to avoid needing to poke around in internals anyway though

Answered By: ThorSummoner