Merge branch '8-universal-property-constructor'

src/property_utils/properties/property.py

@@ -11,6 +11,11 @@
 except ImportError:
     from typing_extensions import Self  # Python <= 3.10
 
+try:
+    from typing import TypeAlias  # Python >= 3.10 pylint: disable=ungrouped-imports
+except ImportError:
+    from typing_extensions import TypeAlias  # Python < 3.10
+
 from property_utils.units.descriptors import (
     MeasurementUnit,
     Dimension,
@@ -568,3 +573,6 @@ def _validate_comparison_input(self, other) -> None:
                 f"cannot compare ({other}) to ({self}); "
                 f"({other}) must have ({self.unit.to_generic()}) units. "
             )
+
+
+p: TypeAlias = Property

src/property_utils/tests/properties/test_property.py

@@ -142,9 +142,9 @@ def test_with_dimension_non_si_units(self):
     def test_with_composite_non_si_units(self):
         self.assert_result("400.0 a / d")
 
-    @args({"unit": Unit1.A**8.19})
+    @args({"unit": Unit1.A**4})
     def test_with_dimension_unregistered_unit_converter(self):
-        self.assert_impossible_conversion()
+        self.assert_result("2000000.0 (a^4)")
 
     @args({"unit": Unit3.C})
     def test_with_simple_unit_unregistered_unit_converter(self):

src/property_utils/tests/units/test_converter_types.py

@@ -85,6 +85,26 @@ def test_with_generic_composite_dimension(self):
         self.assertResult(Unit1Unit4Converter)
 
 
+@add_to(GetConverter_test_suite)
+class TestGetUnregisteredDimensionConverter(TestCase):
+    def subject(self, generic):
+        return get_converter(generic)
+
+    def assert_convert(self, value, from_unit, to_unit):
+        self.assertResultIsNot(None)
+        self.assertEqual(self.cachedResult().convert(10, from_unit, to_unit), value)
+
+    @args({"generic": Unit1 * (Unit4**2)})
+    def test_with_unregistered_composite_dimension(self):
+        self.assert_convert(
+            10 * 10 * (5**2), Unit1.A * (Unit4.D**2), Unit1.a * (Unit4.d**2)
+        )
+
+    @args({"generic": Unit1**2.45})
+    def test_with_unregistered_dimension(self):
+        self.assert_convert(10 * (10**2.45), Unit1.A**2.45, Unit1.a**2.45)
+
+
 @add_to(RegisterConverter_test_suite)
 class TestRegisterConverter(TestCase):
     def subject(self, generic):

src/property_utils/units/converter_types.py

@@ -58,9 +58,17 @@ def get_converter(generic: GenericUnitDescriptor) -> ConverterType:
         raise PropertyUtilsTypeError(
             f"cannot get converter; argument: {generic} is not a generic unit descriptor. "
         )
+    if isinstance(generic, GenericDimension) and generic.power == 1:
+        generic = generic.unit_type
+    elif isinstance(generic, GenericDimension) and generic not in _converters:
+        register_converter(generic)(
+            type(f"{generic}_Converter", (ExponentiatedUnitConverter,), {})
+        )
+    elif isinstance(generic, GenericCompositeDimension) and generic not in _converters:
+        register_converter(generic)(
+            type(f"{generic}_Converter", (CompositeUnitConverter,), {})
+        )
     try:
-        if isinstance(generic, GenericDimension) and generic.power == 1:
-            generic = generic.unit_type
         return _converters[generic]
     except KeyError:
         raise UndefinedConverterError(