ENH: test binary functions with python scalars

[ev-br]

Make strides towards the "Scalar support in most functions" rubric of #299

cross-ref data-apis/array-api-compat#271

[ev-br]

Checked locally: it does catch the error reported in data-apis/array-api-compat#271

$ ARRAY_API_TESTS_MODULE=array_api_compat.torch pytest array_api_tests/test_operators_and_elementwise_functions.py::test_minimum_with_scalars --max-examples=10_000 -s
================================= test session starts ==================================
platform linux -- Python 3.11.0, pytest-8.3.4, pluggy-1.5.0
Array API Tests Module: array_api_compat.torch (version unknown). API Version: 2024.12. Enabled Extensions: fft, linalg
rootdir: /home/ev-br/repos/array-api-tests
configfile: pytest.ini
plugins: metadata-3.1.1, json-report-1.5.0, hypothesis-6.127.2
collected 1 item                                                                       

array_api_tests/test_operators_and_elementwise_functions.py F

======================================= FAILURES =======================================
______________________________ test_minimum_with_scalars _______________________________

    @pytest.mark.min_version("2024.12")
>   @given(hh.array_and_py_scalar(dh.real_float_dtypes))

array_api_tests/test_operators_and_elementwise_functions.py:1511: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
array_api_tests/test_operators_and_elementwise_functions.py:1514: in test_minimum_with_scalars
    out = xp.minimum(x1, x2)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

x1 = tensor([]), x2 = 0.0, kwargs = {}

    @_wraps(f)
    def _f(x1, x2, /, **kwargs):
        x1, x2 = _fix_promotion(x1, x2)
>       return f(x1, x2, **kwargs)
E       TypeError: minimum(): argument 'other' (position 2) must be Tensor, not float
E       Falsifying example: test_minimum_with_scalars(
E           x1x2=(tensor([]), 0.0),  # or any other generated value
E       )

../array-api-compat/array_api_compat/torch/_aliases.py:97: TypeError
=================================== warnings summary ===================================
array_api_tests/__init__.py:91
  /home/ev-br/repos/array-api-tests/array_api_tests/__init__.py:91: HypothesisWarning: Could not determine whether module array_api_compat.torch is an Array API library
    xps = array_api.make_strategies_namespace(xp, api_version=api_version)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=============================== short test summary info ================================
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_minimum_with_scalars - TypeError: minimum(): argument 'other' (position 2) must be Tensor, not float
============================= 1 failed, 1 warning in 6.27s =============================

[ev-br]

The 2024.12 changelog lists the following binary functions which accept scalars as one of its arguments:

• add
• atan2
• bitwise_and
• bitwise_left_shift
• bitwise_or
• bitwise_right_shift
• bitwise_xor
• copysign
• divide
• equal
• floor_divide
• greater
• greater_equal
• hypot
• less
• less_equal
• logaddexp
• logical_and
• logical_or
• logical_xor
• maximum
• minimum
• multiply
• nextafter
• not_equal
• pow
• remainder
• result_type
• subtract
• where

[ev-br]

For torch, rejecting scalars is a rule, accepting them is an exception:

$ ARRAY_API_TESTS_MODULE=array_api_compat.torch pytest array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_bool -v --max-examples 100
...
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_bool[logical_and] - TypeError: logical_and(): argument 'other' (position 2) must be Tensor, not bool
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_bool[logical_or] - TypeError: logical_or(): argument 'other' (position 2) must be Tensor, not bool
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_bool[logical_xor] - TypeError: logical_xor(): argument 'other' (position 2) must be Tensor, not bool

and

$ ARRAY_API_TESTS_MODULE=array_api_compat.torch pytest array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_bool -v --max-examples 100
...
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[atan2] - TypeError: atan2(): argument 'other' (position 2) must be Tensor, not float
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[copysign] - TypeError: copysign() received an invalid combination of arguments - got (float, Te...
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[hypot] - TypeError: hypot(): argument 'other' (position 2) must be Tensor, not float
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[logaddexp] - TypeError: logaddexp(): argument 'other' (position 2) must be Tensor, not float
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[maximum] - TypeError: maximum(): argument 'other' (position 2) must be Tensor, not float
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[minimum] - TypeError: minimum(): argument 'other' (position 2) must be Tensor, not float
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[equal] - ExceptionGroup: Hypothesis found 2 distinct failures. (2 sub-exceptions)
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[neq] - ExceptionGroup: Hypothesis found 2 distinct failures. (2 sub-exceptions)
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[less] - ExceptionGroup: Hypothesis found 2 distinct failures. (2 sub-exceptions)
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[les_equal] - TypeError: less_equal() received an invalid combination of arguments - got (float, ...
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[greater] - TypeError: greater() received an invalid combination of arguments - got (float, Ten...
FAILED array_api_tests/test_operators_and_elementwise_functions.py::test_binary_with_scalars_real[greater_equal] - TypeError: greater_equal() received an invalid combination of arguments - got (floa...

Worth noting that I'm not even trying to cover the dtypes. I'm pretty sure a lot of them have missing kernels (uints, complex etc).

[ev-br]

Merging to continue improving the 2024.12 coverage.