Merge branch '28-empty-composite-dimension'

Author: Maxcode123

src/property_utils/properties/property.py

@@ -217,7 +217,7 @@ def __mul__(self, other) -> "Property":
         if isinstance(other, Property):
             _other = self._unit_preconversion(other)
             return Property(
-                self.value * _other.value, (self.unit * _other.unit).simplified()
+                self.value * _other.value, self._simplify_units(self.unit * _other.unit)
             )
         raise PropertyBinaryOperationError(
             f"cannot multiply {self} with {other}; "
@@ -268,7 +268,7 @@ def __truediv__(self, other) -> "Property":
                 raise PropertyBinaryOperationError(
                     f"cannot divide {self} with {other}; denominator's value is zero. "
                 ) from None
-            return Property(value, (self.unit / _other.unit).simplified())
+            return Property(value, self._simplify_units(self.unit / _other.unit))
         raise PropertyBinaryOperationError(
             f"cannot divide {self} with {other}; "
             "denominator must be numeric or Property. "
@@ -299,7 +299,7 @@ def __rtruediv__(self, other) -> "Property":
                 raise PropertyBinaryOperationError(
                     f"cannot divide {self} with {other}; denominator's value is zero. "
                 ) from None
-            return Property(value, (other.unit / self.unit).simplified())
+            return Property(value, self._simplify_units(other.unit / self.unit))
         raise PropertyBinaryOperationError(
             f"cannot divide {self} with {other}; "
             "numerator must be numeric or Property. "
@@ -727,3 +727,15 @@ def _simple_unit_preconversion(self, unit: MeasurementUnit) -> MeasurementUnit:
         multiplication or division with this property.
         """
         return self._dimension_unit_preconversion(unit**1).unit
+
+    def _simplify_units(self, unit: CompositeDimension) -> UnitDescriptor:
+        """
+        Simplifies the composite dimension and returns NON_DIMENSIONAL if the simplified
+        composite does not have units.
+        """
+        unit = unit.simplified()
+
+        if unit.has_no_units():
+            return NonDimensionalUnit.NON_DIMENSIONAL
+
+        return unit

src/property_utils/tests/properties/test_property.py

@@ -346,6 +346,10 @@ def test_with_exponentiated_property(self):
     def test_with_inverse_property(self):
         self.assert_result("10.4 ")
 
+    @args({"other": Property(2, Unit1.A ** (-1))})
+    def test_produced_units_with_inverse_property(self):
+        self.assertEqual(self.result().unit, NonDimensionalUnit.NON_DIMENSIONAL)
+
     @args({"other": Property(4, Unit2.B)})
     def test_with_other_propperty(self):
         self.assert_result("20.8 A * B")
@@ -499,6 +503,10 @@ def test_with_exponentiated_property(self):
     def test_with_same_property(self):
         self.assert_result("3.0 ")
 
+    @args({"other": Property(2, Unit1.A)})
+    def test_produced_units_with_same_property(self):
+        self.assertEqual(self.result().unit, NonDimensionalUnit.NON_DIMENSIONAL)
+
     @args({"other": Property(2, Unit2.B)})
     def test_with_other_propperty(self):
         self.assert_result("3.0 A / B")
@@ -639,6 +647,10 @@ def test_with_exponentiated_property(self):
     def test_with_same_property(self):
         self.assert_result("0.2 ")
 
+    @args({"other": Property(2, Unit1.A)})
+    def test_produced_units_with_same_property(self):
+        self.assertEqual(self.result().unit, NonDimensionalUnit.NON_DIMENSIONAL)
+
     @args({"other": Property(2, Unit2.B)})
     def test_with_other_propperty(self):
         self.assert_result("0.2 B / A")

src/property_utils/tests/units/test_descriptors.py

@@ -2006,6 +2006,14 @@ def test_with_aliased_denominator_composite_dimension(self):
     def test_with_fully_aliased_composite_dimension(self):
         self.assertResultTrue()
 
+@add_to(GenericCompositeDimension_test_suite)
+class TestGenericCompositeDimensionHasNoUnits(TestDescriptor):
+    def test_with_measurement_units(self):
+        self.assertFalse(generic_composite_dimension().has_no_units())
+
+    def test_with_no_measurement_units(self):
+        self.assertTrue(GenericCompositeDimension().has_no_units())
+
 
 @add_to(CompositeDimension_test_suite)
 class TestCompositeDimensionFromDescriptor(TestDescriptor):
@@ -2568,6 +2576,19 @@ def test_objects_are_not_persisted(self):
         self.assertNotEqual(ids(composite.numerator), ids(inverse.denominator))
         self.assertNotEqual(ids(composite.denominator), ids(inverse.numerator))
 
+@add_to(CompositeDimension_test_suite)
+class TestCompositeDimensionHasNoUnits(TestDescriptor):
+    def test_with_units(self):
+        self.assertFalse(composite_dimension().has_no_units())
+
+    def test_with_no_units(self):
+        self.assertTrue(CompositeDimension().has_no_units())
+
+    def test_with_same_unit_type(self):
+        self.assertFalse(CompositeDimension([Unit1.A],[Unit1.a]).has_no_units())
+
+    def test_with_same_unit(self):
+        self.assertFalse(CompositeDimension([Unit1.A],[Unit1.A]).has_no_units())
 
 @add_to(CompositeDimension_test_suite)
 class TestCompositeDimensionMultiplication(TestDescriptorBinaryOperation):

src/property_utils/units/descriptors.py

@@ -1314,6 +1314,21 @@ def is_equivalent(self, other: GenericUnitDescriptor) -> bool:
 
         return False
 
+    def has_no_units(self) -> bool:
+        """
+        Returns True if the generic composite dimension does not have any units, False
+        otherwise.
+
+        Examples:
+            >>> class LengthUnit(MeasurementUnit): ...
+
+            >>> GenericCompositeDimension().has_no_units()
+            True
+            >>> GenericCompositeDimension([LengthUnit]).has_no_units()
+            False
+        """
+        return len(self.denominator) == 0 and len(self.numerator) == 0
+
     def _numerator_copy(self) -> List[GenericDimension]:
         return [replace(n) for n in self.numerator]
 
@@ -1743,6 +1758,21 @@ def inverse(self) -> "CompositeDimension":
         """
         return CompositeDimension(self._denominator_copy(), self._numerator_copy())
 
+    def has_no_units(self) -> bool:
+        """
+        Returns True if the composite dimension does not have any units, False otherwise.
+
+        Examples:
+            >>> class LengthUnit(MeasurementUnit):
+            ...     METER = "m"
+
+            >>> CompositeDimension().has_no_units()
+            True
+            >>> CompositeDimension([LengthUnit.METER]).has_no_units()
+            False
+        """
+        return len(self.denominator) == 0 and len(self.numerator) == 0
+
     def _numerator_copy(self) -> List[Dimension]:
         return [replace(n) for n in self.numerator]