regex based fixture names for parameter inclusion

[RonnyPfannschmidt]

follow-up to #5571

@pytest.fixture(name=re.compile("user_(?P<role>user|mod|admin)")
def system_user(request):
   role = get_role_by(name=request.match.group("role"))
   return create_user(..., role=role)

[nicoddemus]

Hmm my initial gut feeling for this is -1, because:

1. pytest fixtures are already considered "magical" and implicit. This makes it even more so, because now we don't have an explicit def user_admin, def user_mod, etc, to search for the fixture definition.

2. We already have a way to express the above by making fixtures that return a factory:

   @pytest.fixture
   def user_factory():
       def fac(role):
           role = get_role_by(name=request.match.group("role"))
           return create_user(..., role=role) 
       return fac
       
   
   def test_foo(user_factory):
       admin = user_factory('admin')  

   This is a little more verbose, but I think it being more explicit overweights that.

The idea proposed here is to basically provide a way to pass a parameter to a fixture from inside a test, which I'm not against per-se; but using a regex approach doesn't really strikes me as a good way to accomplish that.

We might consider adding another way to do the same thing with a special decorator:

@pytest.fixture_factory(rule=None)
def system_user(request):
    role = get_role_by(name=request.getparam("role"))
    return create_user(..., role=role)

def test_foo(system_user):
   admin = system_user('admin')  # other fixtures calling this 
                                 # will also receive the same instance

But I'm not too sure either.