python data_error ai_generated true

Failed: [pytest] empty parameter set in 'test_parse' at tests/test_parse.py:12

ID: python/pytest-parametrize-empty-list

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-07-19First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
7.x active — — —
8.x active — — —

Root Cause

pytest.mark.parametrize received an empty list for argvalues, so pytest reports an empty parameter set and fails the test by default (controlled by empty_parameter_set_mark).

generic

中文

pytest.mark.parametrize 收到空列表作为 argvalues，pytest 报告空参数集并默认使测试失败（由 empty_parameter_set_mark 控制）。

Workarounds

  1. 90% success 
    # pytest.ini
[pytest]
empty_parameter_set_mark = skip
  2. 88% success 
    CASES = load_cases() or [pytest.param(None, marks=pytest.mark.skip('no cases'))]

@pytest.mark.parametrize('case', CASES)
def test_parse(case): ...

Dead Ends

Common approaches that don't work:

  1. 70% fail

    Loses parameterization entirely; the test now runs once with undefined arguments and fails differently.

  2. 65% fail

    Hides the fact that the data source is empty, which is often the actual bug worth surfacing.