Cannot stack @parametrize_with_cases() if cases use fixtures and have the same suffix name

[jcwilson]

Running this code:

from pytest_cases import parametrize_with_cases

def a_case(monkeypatch):
    return True

def b_case(freezer):
    return True

@parametrize_with_cases("a", cases=".", prefix="a_")
@parametrize_with_cases("b", cases=".", prefix="b_")
def test_something(a, b):
    pass

results in this error:

Test session starts (platform: linux, Python 3.8.4, pytest 5.4.3, pytest-sugar 0.9.4)
rootdir: /code/components/echo, inifile: pytest.ini
plugins: mock-3.2.0, cases-2.0.4, sugar-0.9.4, freezegun-0.4.1, cov-2.10.0
collecting ...
―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――― ERROR collecting tests/test_authentication_middleware.py ―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――tests/test_authentication_middleware.py:14: in <module>
    def test_something(a, b):
/home/aladdin-user/.local/lib/python3.8/site-packages/pytest_cases/case_parametrizer_new.py:99: in _apply_parametrization
    argvalues = get_parametrize_args(cases_funs)
/home/aladdin-user/.local/lib/python3.8/site-packages/pytest_cases/case_parametrizer_new.py:238: in get_parametrize_args
    return [c for _f in cases_funs for c in case_to_argvalues(_f)]
/home/aladdin-user/.local/lib/python3.8/site-packages/pytest_cases/case_parametrizer_new.py:238: in <listcomp>
    return [c for _f in cases_funs for c in case_to_argvalues(_f)]
/home/aladdin-user/.local/lib/python3.8/site-packages/pytest_cases/case_parametrizer_new.py:291: in case_to_argvalues
    raise NotImplementedError("We should check if this is the same or another and generate a new name in that "
E   NotImplementedError: We should check if this is the same or another and generate a new name in that case

However, if I remove monkeypatch or freezer from one of the cases, or if I change the name of one of the cases, it runs the test.

[smarie]

Thanks for reporting ! I'll have a look

[smarie]

Sorry I finally take the time to look now actually - I had to close a series of other things.
I was able to reproduce the issue (note for future readers: no need to use the freezer plugin, using request fixture instead of freezer also produces the same bug)

When pytest cases collects some cases that require a fixture, it creates a fixture for that case. This fixture is registered locally in the current module. But of course local fixtures need to have unique names. In your example the name (that I derive from the case id) is case in both situations. I therefore changed a bit the logic in order to guarantee uniqueness. I should release the fix soon.

[jcwilson]

Thanks for the quick response!

And yeah, there's nothing special about the fixture names in my example. Just had them handy. Sorry if that added some confusion.

[smarie]

2.1.0 was released, please feel free to reopen if it does not fix the issue for you ! Thanks a lot for contributing