python type_error ai_generated true

TypeError: test_func() missing 1 required positional argument: 'value'

ID: python/pytest-fixture-indirect-param-missing

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-09-21First Seen

Version Compatibility

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

Root Cause

pytest.mark.parametrize(..., indirect=True) was used, but the named fixture does not actually accept a 'request' argument to read request.param, so the fixture returns nothing and the test sees a missing argument.

generic

中文

使用了 pytest.mark.parametrize(..., indirect=True)，但指定的 fixture 没有接受 'request' 参数来读取 request.param，因此 fixture 不返回内容，测试看到缺少参数。

Workarounds

  1. 95% success 
    @pytest.fixture
def value(request):
    return request.param * 2

@pytest.mark.parametrize('value', [1, 2, 3], indirect=True)
def test_func(value):
    assert value in (2, 4, 6)
  2. 90% success 
    @pytest.fixture
def make_value():
    def _make(n):
        return n * 2
    return _make

@pytest.mark.parametrize('n', [1, 2, 3])
def test_func(make_value, n):
    assert make_value(n) in (2, 4, 6)

Dead Ends

Common approaches that don't work:

  1. 75% fail

    Changes the fixture into a direct parameter, so the fixture logic (setup, teardown) never runs.

  2. 80% fail

    Hides the real problem; the fixture still does not receive the parametrized value.