Chain multiple fixtures pytest/unittest hybrid

Question

I am working with a code base which which is mostly written with unittest. The tests are run with pytest. I am trying to simplify the tests by parameterizing some of them. To work towards this goal, I am trying to learn how to use pytest fixtures and refactor some of the existing unittest-based tests. The current tests have a global fixture in conftest.py:

@pytest.fixture(autouse=True)
def register_cleanup():
    yield True
    print("cleaning up database")

Now I want to add a fixture which is specific to one of my test modules, something along the lines of

@pytest.fixture()
def foo_fixture():
    print("setup fixture")
    yield
    print("tear down fixture")


class Foo(unittest.TestCase):
    def setUp(self):
        print('unittest setUp()')

    def test(self):
        print('test')

However, the print() statements in this module fixture never execute. As an intermediate step, I am keeping the unittest-based structure and adding to it. Is it possible to get this working the way I want or do I need to scrap unittest altogether and go directly to pytest.

Where would you expect this fixture to be used? Did you want to turn on autouse=True here as well? In general, fixtures are only executed when they are a parameter to the test, and are less of generic cleanup mechanisms than scoped assumptions — Cireo
@Cireo Do you mean I should add autouse=True to foo_fixture() similarly to register_cleanup()? — Code-Apprentice

wim wim · Accepted Answer · 2017-08-22T18:18:48

You'll want to mark it:

@pytest.mark.usefixtures("foo_fixture")
class Foo(unittest.TestCase):
    ...

Note: you may have more than one conftest.py. Put the more specific fixture into this test subdirectory's conftest.py.

Chain multiple fixtures pytest/unittest hybrid

2 Answers