accessing request.fspath for generating parameters for a test

Question

I know it's impossible to add more tests inside fixtures because they run at test time, and tests are generated at collection time.

But I want to be able to generate parameters to a test based on the path to the test function (to the module where test function is).

Basically, I want something like that:

@pytest.mark.parametrize(
    argnames='letter',
    argvalues=lambda request: list(zip(request.fspath)),
    indirect=True
)
def test_foo(letter):
  assert letter

It should print put a path to the module, letter by letter as a parameter to the function:

foo[/]
foo[t]
foo[e]
foo[s]
foo[t]
foo[.]
foo[p]
foo[y]

This code (above) is definitively not working, but may be there is a way to use fspath as an argument to parametrize?