间接参数化时如何注释request.param？

In the 间接参数化示例 https://docs.pytest.org/en/stable/example/parametrize.html#indirect-parametrization我想输入提示request.param表示特定类型，astr例如。

问题是因为争论fixt必须是request https://docs.pytest.org/en/stable/reference.html#requestFixture 似乎没有办法表明通过的参数是什么类型“选修的param属性”应该是（引用文档）。

有哪些替代方案？也许记录中的类型提示fixt文档字符串，或在test_indirect文档字符串？

@pytest.fixture
def fixt(request):
    return request.param * 3

@pytest.mark.parametrize("fixt", ["a", "b"], indirect=True)
def test_indirect(fixt):
    assert len(fixt) == 3

截至目前（版本 6.2），pytest不提供任何类型提示param属性。如果您只需输入param不管其余的FixtureRequest字段和方法，您可以内联自己的 impl 存根：

from typing import TYPE_CHECKING


if TYPE_CHECKING:
    class FixtureRequest:
        param: str
else:
    from typing import Any
    FixtureRequest = Any


@pytest.fixture
def fixt(request: FixtureRequest) -> str:
    return request.param * 3

如果你想扩展现有的类型FixtureRequest，存根变得更加复杂：

from typing import TYPE_CHECKING


if TYPE_CHECKING:
    from pytest import FixtureRequest as __FixtureRequest
    class FixtureRequest(__FixtureRequest):
        param: str
else:
    from pytest import FixtureRequest


@pytest.fixture
def fixt(request: FixtureRequest) -> str:
    return request.param * 3

理想情况下，pytest将允许通用param输入FixtureRequest, e.g.

P = TypeVar("P")  # generic param type

class FixtureRequest(Generic[P]):
    def __init__(self, param: P, ...):
        ...

然后你就会做

from pytest import FixtureRequest

@pytest.fixture
def fixt(request: FixtureRequest[str]) -> str:
    return request.param * 3

但不确定这种类型是否与当前的一致pytest的代码库 - 我猜它被省略是有原因的......