@parametrize: custom ids are not taken into account for lazy_value argvalues when a single lazy value is used for a tuple of parameters

[smarie]

From #142 @romanponomaryov found out this bug that can be reduced down to:

from pytest_cases import parametrize_with_cases

def case_dumb():
    return 1, 2

def generate_id(**args):
    return "hello"

@parametrize_with_cases('dummy_amount, exp_amount', cases='.', idgen=generate_id)
def test_tuples(dummy_amount, exp_amount):
    assert True

The issue is that the custom id "hello" is not taken into account

[smarie]

For reference this issue is actually lower-level and can be reproduced with

from pytest_cases import lazy_value, parametrize

def case_dumb():
    return 1, 2

@parametrize("a,b", [(1, object()), lazy_value(case_dumb)], ids=["hello", "world"])
def test_foo2(a, b):
    pass

It yields:

test_tmp.py::test_foo2[hello] 
test_tmp.py::test_foo2[case_dumb] 

So the custom id is not taken into account for the lazy value.

[smarie]

@romanponomaryov this will ship with 2.4.0 probably topday when travis wakes up : it seems to be extremely slow these days