Fix TypeError when combining auto_reduce_dimensions=True and non_int_type=Decimal

CHANGES

@@ -18,7 +18,9 @@ Pint Changelog
  (PR #1816)
 - Fix converting to offset units of higher dimension e.g. gauge pressure
  (PR #1949)
-
+- Fix unhandled TypeError when auto_reduce_dimensions=True and non_int_type=Decimal
+ (PR #1853)
+
 
 0.23 (2023-12-08)
 -----------------

pint/testsuite/test_issues.py

@@ -1179,6 +1179,13 @@ def test_issue1505():
  ) # unexpected fail (magnitude should be a decimal)
 
 
+def test_issue_1845():
+ ur = UnitRegistry(auto_reduce_dimensions=True, non_int_type=decimal.Decimal)
+ # before issue 1845 these inputs would have resulted in a TypeError
+ assert ur("km / h * m").units == ur.Quantity("meter ** 2 / hour")
+ assert ur("kW / min * W").units == ur.Quantity("watts ** 2 / minute")
+
+
 @pytest.mark.parametrize(
  "units,spec,expected",
  [

pint/util.py

@@ -495,7 +495,7 @@ def add(self: Self, key: str, value: Number) -> Self:
  UnitsContainer
  A copy of this container.
  """
- newval = self._d[key] + value
+ newval = self._d[key] + self._normalize_nonfloat_value(value)
  new = self.copy()
  if newval:
  new._d[key] = newval
@@ -656,7 +656,7 @@ def __truediv__(self, other: Any):
 
  new = self.copy()
  for key, value in other.items():
- new._d[key] -= value
+ new._d[key] -= self._normalize_nonfloat_value(value)
  if new._d[key] == 0:
  del new._d[key]
 
@@ -670,6 +670,11 @@ def __rtruediv__(self, other: Any):
 
  return self**-1
 
+ def _normalize_nonfloat_value(self, value: Scalar) -> Scalar:
+ if not isinstance(value, int) and not isinstance(value, self._non_int_type):
+ return self._non_int_type(value) # type: ignore[no-any-return]
+ return value
+
 
 class ParserHelper(UnitsContainer):
  """The ParserHelper stores in place the product of variables and