Small cleanups to number entity (#107624)

homeassistant/components/number/__init__.py

@@ -424,22 +424,22 @@ class NumberEntity(Entity, cached_properties=CACHED_PROPERTIES_WITH_ATTR_):
         native_unit_of_measurement = self.native_unit_of_measurement
         unit_of_measurement = self.unit_of_measurement
         if native_unit_of_measurement != unit_of_measurement:
-            assert native_unit_of_measurement
-            assert unit_of_measurement
+            if TYPE_CHECKING:
+                assert native_unit_of_measurement
+                assert unit_of_measurement
 
             value_s = str(value)
             prec = len(value_s) - value_s.index(".") - 1 if "." in value_s else 0
 
             # Suppress ValueError (Could not convert value to float)
             with suppress(ValueError):
-                value_new: float = UNIT_CONVERTERS[device_class].convert(
-                    value,
+                value_new: float = UNIT_CONVERTERS[device_class].converter_factory(
                     native_unit_of_measurement,
                     unit_of_measurement,
-                )
+                )(value)
 
                 # Round to the wanted precision
-                value = method(value_new, prec)
+                return method(value_new, prec)
 
         return value
 
@@ -453,21 +453,22 @@ class NumberEntity(Entity, cached_properties=CACHED_PROPERTIES_WITH_ATTR_):
         native_unit_of_measurement = self.native_unit_of_measurement
         unit_of_measurement = self.unit_of_measurement
         if native_unit_of_measurement != unit_of_measurement:
-            assert native_unit_of_measurement
-            assert unit_of_measurement
+            if TYPE_CHECKING:
+                assert native_unit_of_measurement
+                assert unit_of_measurement
 
-            value = UNIT_CONVERTERS[device_class].convert(
-                value,
+            return UNIT_CONVERTERS[device_class].converter_factory(
                 unit_of_measurement,
                 native_unit_of_measurement,
-            )
+            )(value)
 
         return value
 
     @callback
     def async_registry_entry_updated(self) -> None:
         """Run when the entity registry entry has been updated."""
-        assert self.registry_entry
+        if TYPE_CHECKING:
+            assert self.registry_entry
         if (
             (number_options := self.registry_entry.options.get(DOMAIN))
             and (custom_unit := number_options.get(CONF_UNIT_OF_MEASUREMENT))

homeassistant/components/number/const.py

@@ -475,7 +475,7 @@ DEVICE_CLASS_UNITS: dict[NumberDeviceClass, set[type[StrEnum] | str | None]] = {
     NumberDeviceClass.WIND_SPEED: set(UnitOfSpeed),
 }
 
-UNIT_CONVERTERS: dict[str, type[BaseUnitConverter]] = {
+UNIT_CONVERTERS: dict[NumberDeviceClass, type[BaseUnitConverter]] = {
     NumberDeviceClass.TEMPERATURE: TemperatureConverter,
 }