Hi, @darsor ! Thank you for contributing in allure-python!

Let's better use @typing.overload:

@overload
def step(title: str) -> StepContext:
    ...

@overload
def step(title: _TFunc) -> _TFunc:
    ...

This will require moving StepContext above step.

And it also makes sense to disable type checking when returning the wrapper in StepContext.__call__ for those of us who enable pyright when working on the repo :)

return impl # type: ignore