torch/result_type: add a regression test from array-api-compat#273

Author: ev-br

Diff for: array_api_tests/test_data_type_functions.py

@@ -258,3 +258,13 @@ def test_with_scalars(self, dtypes, data):
         out_scalar = xp.result_type(*inputs)
         assert out_scalar == out
 
+    @pytest.mark.parametrize("dtype_a", (xp.int32, xp.int64) + dh.real_float_dtypes + dh.complex_dtypes)
+    @pytest.mark.parametrize("dtype_b", (xp.int32, xp.int64) + dh.real_float_dtypes + dh.complex_dtypes)
+    def test_gh_273(self, dtype_a, dtype_b):
+        # Regression test for https://github.com/data-apis/array-api-compat/issues/273
+        # Note it is manually parametrized instead of using hypothesis
+        a = xp.asarray([2, 1], dtype=dtype_a)
+        b = xp.asarray([1, -1], dtype=dtype_b)
+        dtype_1 = xp.result_type(a, b, 1.0)
+        dtype_2 = xp.result_type(b, a, 1.0)
+        assert dtype_1 == dtype_2