Merge pull request #463 from neutrinoceros/hotfix_unit_consistency_va…

…lidation

BUG: fix an issue where array functions would raise UnitConsistencyError on unyt arrays using non-default unit registries

unyt/_array_functions.py

@@ -223,8 +223,8 @@ def _validate_units_consistency(objs):
     # because it's already a necessary condition for numpy to use our
     # custom implementations
     units = get_units(objs)
-    sunits = set(units)
-    if len(sunits) == 1:
+    unique_units = set(units)
+    if len(unique_units) == 1 or all(u.is_dimensionless for u in unique_units):
         return units[0]
     else:
         raise UnitInconsistencyError(*units)

unyt/tests/test_array_functions.py

@@ -18,6 +18,8 @@
     UnytError,
 )
 from unyt.testing import assert_array_equal_units
+from unyt.unit_object import Unit
+from unyt.unit_registry import UnitRegistry
 
 NUMPY_VERSION = Version(version("numpy"))
 
@@ -265,6 +267,23 @@ def test_wrapping_completeness():
         assert function in all_funcs
 
 
+@pytest.mark.parametrize(
+    "arrays",
+    [
+        [np.array([1]), [2] * Unit()],
+        [np.array([1]), [2] * Unit(registry=UnitRegistry())],
+        # [[1], [2] * Unit()],
+    ],
+)
+def test_unit_validation(arrays):
+    # see https://github.com/yt-project/unyt/issues/462
+    # numpy.concatenate isn't essential to this test
+    # what we're really testing is the unit consistency validation
+    # underneath, but we do so using public API
+    res = np.concatenate(arrays)
+    assert res.units.is_dimensionless
+
+
 def test_array_repr():
     arr = [1, 2, 3] * cm
     assert re.fullmatch(r"unyt_array\(\[1, 2, 3\], (units=)?'cm'\)", np.array_repr(arr))