How to write complex skip decorators?

[lucascolley]

From the docs, it seems like the intended way to write skip decorators (that you'd import from e.g. conftest.py) is to use skipif (https://docs.pytest.org/en/6.2.x/skipping.html#id1). However, the condition shown in the example is simple and doesn't need to interact with any other parametrizations. Is it possible to get skipif to work when you also need to inspect arguments as part of the condition to skip?

In https://github.com/scipy/scipy/blob/4a6db1500dc62870865fe7827524abd332a88fd9/scipy/conftest.py#L147-L180, we have decorators which perform the skips we want correctly, however, (IIUC) because we use skip rather than skipif, when we use -rsx, the skips are reported as coming from conftest.py, e.g. SKIPPED [27] scipy/conftest.py:159: is_isomorphic only supports NumPy backend. Is there a way to write the decorators such that the skips are reported from the test in which they originate?

We can recover that information from --verbose instead, but it would be much easier if this worked with -rsx. Cheers!

---

# conftest.py
array_api_compatible = pytest.mark.parametrize("xp", xp_available_backends.values())

def skip_if_array_api_gpu(func):
    reason = "do not run with Array API on and not on CPU"
    # method gets there as a function so we cannot use inspect.ismethod
    if '.' in func.__qualname__:
        @wraps(func)
        def wrapped(self, *args, **kwargs):
            xp = kwargs["xp"]
            if SCIPY_ARRAY_API and SCIPY_DEVICE != 'cpu':
                if xp.__name__ == 'cupy':
                    pytest.skip(reason=reason)
                elif xp.__name__ == 'torch':
                    if 'cpu' not in torch.empty(0).device.type:
                        pytest.skip(reason=reason)
            return func(self, *args, **kwargs)
    else:
        @wraps(func)
        def wrapped(*args, **kwargs):
            xp = kwargs["xp"]
            if SCIPY_ARRAY_API and SCIPY_DEVICE != 'cpu':
                if xp.__name__ == 'cupy':
                    pytest.skip(reason=reason)
                elif xp.__name__ == 'torch':
                    if 'cpu' not in torch.empty(0).device.type:
                        pytest.skip(reason=reason)
            return func(*args, **kwargs)
    return wrapped

x-ref https://stackoverflow.com/questions/77687258/how-to-write-complex-pytest-skip-decorators