Add test_pref_vector_to_weighting_check

Author: ValerianRey

tests/unit/aggregation/test_pref_vector_utils.py

@@ -0,0 +1,26 @@
+from contextlib import nullcontext as does_not_raise
+
+import torch
+from pytest import mark, raises
+from torch import Tensor
+from unit._utils import ExceptionContext
+
+from torchjd.aggregation._pref_vector_utils import _pref_vector_to_weighting
+from torchjd.aggregation.mean import _MeanWeighting
+
+
+@mark.parametrize(
+    ["pref_vector", "expectation"],
+    [
+        (None, does_not_raise()),
+        (torch.ones([]), raises(ValueError)),
+        (torch.ones([0]), does_not_raise()),
+        (torch.ones([1]), does_not_raise()),
+        (torch.ones([5]), does_not_raise()),
+        (torch.ones([1, 1]), raises(ValueError)),
+        (torch.ones([1, 1, 1]), raises(ValueError)),
+    ],
+)
+def test_pref_vector_to_weighting_check(pref_vector: Tensor | None, expectation: ExceptionContext):
+    with expectation:
+        _ = _pref_vector_to_weighting(pref_vector, default=_MeanWeighting())