SyntaxError when a case id is a reserved keyword and the case is transformed into a fixture behind the scenes

[wonboyn]

Hi there,

I've just started getting an error during pytest discovery/collection.
The error is for one specific test function but I'm struggling to understand what the issue is.

When I run discovery, it reports the following error:
/usr/local/lib/python3.6/dist-packages/_pytest/python.py:578: in _importtestmodule mod = import_path(self.fspath, mode=importmode) /usr/local/lib/python3.6/dist-packages/_pytest/pathlib.py:524: in import_path importlib.import_module(module_name) /usr/lib/python3.6/importlib/__init__.py:126: in import_module return _bootstrap._gcd_import(name[level:], package, level) <frozen importlib._bootstrap>:994: in _gcd_import ??? <frozen importlib._bootstrap>:971: in _find_and_load ??? <frozen importlib._bootstrap>:955: in _find_and_load_unlocked ??? <frozen importlib._bootstrap>:665: in _load_unlocked ??? /usr/local/lib/python3.6/dist-packages/_pytest/assertion/rewrite.py:170: in exec_module exec(co, module.__dict__) testing/unit/web/models/test_aws_credential_pool_dao.py:72: in <module> @parametrize_with_cases('val,exp', cases=GetFirstNotUsedTestCases) /usr/local/lib/python3.6/dist-packages/pytest_cases/common_pytest.py:894: in apply return apply_decorator(test_or_fixture_func, container) /usr/local/lib/python3.6/dist-packages/pytest_cases/case_parametrizer_new.py:161: in _apply_parametrization return _parametrize_with_cases(f, host_class_or_module) /usr/local/lib/python3.6/dist-packages/pytest_cases/fixture_parametrize_plus.py:1020: in parametrize_plus_decorate idstyle=_idstyle, scope=scope) /usr/local/lib/python3.6/dist-packages/pytest_cases/fixture_core1_unions.py:379: in _fixture_union @with_signature("%s(%s, request)" % (name, ', '.join(unique_fix_alt_names))) /usr/local/lib/python3.6/dist-packages/makefun/main.py:940: in replace_f **attrs /usr/local/lib/python3.6/dist-packages/makefun/main.py:190: in create_function func_name_from_str, func_signature, func_signature_str = get_signature_from_string(func_signature, evaldict) /usr/local/lib/python3.6/dist-packages/makefun/main.py:441: in get_signature_from_string dummy_f = _make(func_name_, [], body, evaldict) /usr/local/lib/python3.6/dist-packages/makefun/main.py:612: in _make code = compile(body, filename, 'single') E File "<makefun-gen-212>", line 1 E def test_get_first_not_used_val_exp(None, request): E ^ E SyntaxError: invalid syntax ------------------------------------------------------------------- Captured stderr ------------------------------------------------------------------- Error in generated code: def test_get_first_not_used_val_exp(None, request): pass

The test cases class (GetFirstNotUsedTestCases) consists of the following:
`class GetFirstNotUsedTestCases:

@case(id="None")
def case_none(self, manage_test_data):
    # Grab the required values
    valid_user = manage_test_data["user_pool"][7].user_name
    return None, valid_user

`

Any help to figure out what's going wrong would be greatly appreciated.

Cheers

Tim

[wonboyn]

Hi there,

I found the issue. I had a couple of test cases where I had used a reserved word as the case id - specifically I had used the following as case id's: None, False, True

It would be nice to be able to use any string as a case id & not have to worry about this sort of issue.

Thanks

Tim

[smarie]

Thanks @wonboyn !! Indeed I was able to reproduce the bug. It arises when a case function is transformed into a fixture, and that fixture gets a name that can not actually be used as an argument name (False, True, None, ... as you pointed out).

Here is a reproducible example

from pytest_cases import parametrize_with_cases


class FooCases:

    def case_None(self, tmpdir):
        return 1

    def case_True(self, tmpdir):
        return 1

    def case_False(self, tmpdir):
        return 1


@parametrize_with_cases("foo", cases=FooCases)
def test_issue_230(foo):
    pass

[smarie]

Fixed in 3.6.4 to be released soon

[smarie]

3.6.4 is available. Can you try and let me know ? Thanks !

[wonboyn]

Thanks for that. Works a treat

[smarie]

Thanks for the feedback @wonboyn !

[lawschlosser]

[EDIT] Nevermind, didn't realize 3.x tag/releases also work with python 2.7
@smarie Any chance this can be backported to a python 2.x release? (sorry, had to ask)