pytest_parametrize.py

from typing import (
    Any,
    Dict,
    NamedTuple,
)

import pytest


class Case(NamedTuple):
    name: str
    kwargs: Dict[str, Any]


def case(test_case_name=None, **kwargs):
    if test_case_name is None:
        test_case_name = ' '.join(f'{k}={v}' for k,v in sorted(kwargs.items()))
    return Case(test_case_name, kwargs)


def parametrize(*cases: Case):
    arg_names = sorted({k for c in cases for k in c.kwargs})
    return pytest.mark.parametrize(
        ','.join(arg_names),
        [tuple(c.kwargs[a] for a in arg_names) for c in cases],
        ids=[c.name for c in cases],
    )


# Usage:
@parametrize(
    case("some test case", a=1, b=2, result=3),
    case(a=10, b=11, result=21),
    case(a=88, b=99, result=88 + 99),
    case(a=5, b=7, result=5 + 7),
)
def test_sum(a, b, result):
    assert a + b == result