Lazy fixtures not working at all

[brian-barba-hernandez]

I had a few lazy fixtures loaded in some of my tests like this:

@pytest.mark.parametrize('user_group', [
        pytest.lazy_fixture('user_group_national_manager'),
        pytest.lazy_fixture('user_group_regional_manager'), 
        pytest.lazy_fixture('user_group_lwi_staff') 
    ])

Now, when the tests are being loaded it fails collecting them with:

/usr/local/lib/python3.6/dist-packages/pluggy/hooks.py:258: in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
/usr/local/lib/python3.6/dist-packages/pluggy/manager.py:67: in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
/usr/local/lib/python3.6/dist-packages/pluggy/manager.py:61: in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
/usr/local/lib/python3.6/dist-packages/_pytest/python.py:242: in pytest_pycollect_makeitem
    res = list(collector._genfunctions(name, obj))
/usr/local/lib/python3.6/dist-packages/_pytest/python.py:432: in _genfunctions
    self.ihook.pytest_generate_tests(metafunc=metafunc)
/usr/local/lib/python3.6/dist-packages/pluggy/hooks.py:258: in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
/usr/local/lib/python3.6/dist-packages/pluggy/manager.py:67: in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
/usr/local/lib/python3.6/dist-packages/pluggy/manager.py:61: in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
/usr/local/lib/python3.6/dist-packages/pytest_lazyfixture.py:70: in pytest_generate_tests
    normalize_metafunc_calls(metafunc, 'funcargs')
/usr/local/lib/python3.6/dist-packages/pytest_lazyfixture.py:77: in normalize_metafunc_calls
    calls = normalize_call(callspec, metafunc, valtype, used_keys)
/usr/local/lib/python3.6/dist-packages/pytest_lazyfixture.py:101: in normalize_call
    _, fixturenames_closure, arg2fixturedefs = fm.getfixtureclosure([val.name], metafunc.definition.parent)
E   ValueError: not enough values to unpack (expected 3, got 2)

If I changed the code to use tuples or arrays, the tests run but the lazy fixture is not loaded making the tests fail:

@pytest.mark.parametrize('user_group', [
        (pytest.lazy_fixture('user_group_national_manager'),),
        (pytest.lazy_fixture('user_group_regional_manager'),),
        (pytest.lazy_fixture('user_group_lwi_staff'),)
    ])

    assert response.status_code == 200
E   assert 403 == 200
E    +  where 403 = <HttpResponseForbidden status_code=403, "text/html">.status_code

This was working properly before the upgrade to 0.5.0

I tried to use the format specified in the README with no luck. I had to remove the lazy fixture and use a different approach in the meantime.

Any idea of what's broken?

FYI, each fixture just creates a Group and adds the user to the created group. I assert the groups the user belongs to and it belongs to none so the fixture is not loaded when the test runs.

[YannickJadoul]

@brian-barba-hernandez What version of pytest are you using? Maybe the tests failed to pick up an API change in between the 3.2.0 and the latest that are being tested?

[YannickJadoul]

The problem is this API change in pytest's FixtureManager: https://github.com/pytest-dev/pytest/commit/1dc5e97ac255b3a50b80b2a5400d7d467e952532#diff-6725679ae3a6464a250386ddaec4b18bR1150

I thought I'd looked up the version in which this was changed, and saw that it was the same version in which Metafunc got the definition attribute (https://github.com/pytest-dev/pytest/commit/180ae0920235e883138d56fa4274565793058465#diff-b33fa7b9ea0fc8ba664d4ca04002823aR740), but maybe I've missed something, there.

[brian-barba-hernandez]

@YannickJadoul These are the libs I'm using while testing:

platform linux -- Python 3.6.5, pytest-3.6.4, py-1.7.0, pluggy-0.7.1
Django settings: ***.settings.dev (from environment variable)
rootdir: /code, inifile: setup.cfg
plugins: timeout-1.3.3, lazy-fixture-0.5.0, django-3.4.4, cov-2.6.0, asyncio-0.9.0, celery-4.1.1

[YannickJadoul]

As a quick fix, updating pytest to 4.1.0 should work. But I'm looking into this, because this should also work!

[YannickJadoul]

Found it. The version numbers where not sorted correctly when I looked up the release of these two API changes. This should be correct:

$ git tag --contains 180ae0920235e883138d56fa4274565793058465 | sort -V
3.6.0
3.6.1
3.6.2
3.6.3
3.6.4
3.7.0
3.7.1
3.7.2
3.7.3
3.7.4
3.8.0
3.8.1
3.8.2
3.9.0
3.9.1
3.9.2
3.9.3
3.10.0
3.10.1
4.0.0
4.0.1
4.0.2
4.1.0
$ git tag --contains 1dc5e97ac255b3a50b80b2a5400d7d467e952532 | sort -V
3.7.0
3.7.1
3.7.2
3.7.3
3.7.4
3.8.0
3.8.1
3.8.2
3.9.0
3.9.1
3.9.2
3.9.3
3.10.0
3.10.1
4.0.0
4.0.1
4.0.2
4.1.0

And your version 3.6.4 contains one change, but not the other.

Apologies, I should've checked this better when I made that PR :-/ Should be fixed in #34, though (or by updating pytest to a version >= 3.7.0).

[brian-barba-hernandez]

@YannickJadoul Many thanks :)

[TvoroG]

Published new version 0.5.1 with fix from @YannickJadoul.

Thanks @brian-barba-hernandez for opening the issue!

[brian-barba-hernandez]

@TvoroG You're welcome, thanks for the fix!