Use translations on NumberEntity unit_of_measurement property (#132095)

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

homeassistant/components/number/__init__.py

@@ -384,6 +384,18 @@ class NumberEntity(Entity, cached_properties=CACHED_PROPERTIES_WITH_ATTR_):
         ):
             return self.hass.config.units.temperature_unit
 
+        if (translation_key := self._unit_of_measurement_translation_key) and (
+            unit_of_measurement
+            := self.platform.default_language_platform_translations.get(translation_key)
+        ):
+            if native_unit_of_measurement is not None:
+                raise ValueError(
+                    f"Number entity {type(self)} from integration '{self.platform.platform_name}' "
+                    f"has a translation key for unit_of_measurement '{unit_of_measurement}', "
+                    f"but also has a native_unit_of_measurement '{native_unit_of_measurement}'"
+                )
+            return unit_of_measurement
+
         return native_unit_of_measurement
 
     @cached_property

homeassistant/components/sensor/__init__.py

@@ -467,22 +467,6 @@ class SensorEntity(Entity, cached_properties=CACHED_PROPERTIES_WITH_ATTR_):
             return self.entity_description.suggested_unit_of_measurement
         return None
 
-    @cached_property
-    def _unit_of_measurement_translation_key(self) -> str | None:
-        """Return translation key for unit of measurement."""
-        if self.translation_key is None:
-            return None
-        if self.platform is None:
-            raise ValueError(
-                f"Sensor {type(self)} cannot have a translation key for "
-                "unit of measurement before being added to the entity platform"
-            )
-        platform = self.platform
-        return (
-            f"component.{platform.platform_name}.entity.{platform.domain}"
-            f".{self.translation_key}.unit_of_measurement"
-        )
-
     @final
     @property
     @override

homeassistant/helpers/entity.py

@@ -647,6 +647,22 @@ class Entity(
             f".{self.translation_key}.name"
         )
 
+    @cached_property
+    def _unit_of_measurement_translation_key(self) -> str | None:
+        """Return translation key for unit of measurement."""
+        if self.translation_key is None:
+            return None
+        if self.platform is None:
+            raise ValueError(
+                f"Entity {type(self)} cannot have a translation key for "
+                "unit of measurement before being added to the entity platform"
+            )
+        platform = self.platform
+        return (
+            f"component.{platform.platform_name}.entity.{platform.domain}"
+            f".{self.translation_key}.unit_of_measurement"
+        )
+
     def _substitute_name_placeholders(self, name: str) -> str:
         """Substitute placeholders in entity name."""
         try:

tests/components/number/test_init.py

@@ -2,7 +2,7 @@
 
 from collections.abc import Generator
 from typing import Any
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, patch
 
 import pytest
 
@@ -836,6 +836,69 @@ async def test_custom_unit_change(
     assert state.attributes[ATTR_UNIT_OF_MEASUREMENT] == default_unit
 
 
+async def test_translated_unit(
+    hass: HomeAssistant,
+) -> None:
+    """Test translated unit."""
+
+    with patch(
+        "homeassistant.helpers.service.translation.async_get_translations",
+        return_value={
+            "component.test.entity.number.test_translation_key.unit_of_measurement": "Tests"
+        },
+    ):
+        entity0 = common.MockNumberEntity(
+            name="Test",
+            native_value=123,
+            unique_id="very_unique",
+        )
+        entity0.entity_description = NumberEntityDescription(
+            "test",
+            translation_key="test_translation_key",
+        )
+        setup_test_component_platform(hass, DOMAIN, [entity0])
+
+        assert await async_setup_component(
+            hass, "number", {"number": {"platform": "test"}}
+        )
+        await hass.async_block_till_done()
+
+        entity_id = entity0.entity_id
+        state = hass.states.get(entity_id)
+        assert state.attributes[ATTR_UNIT_OF_MEASUREMENT] == "Tests"
+
+
+async def test_translated_unit_with_native_unit_raises(
+    hass: HomeAssistant,
+) -> None:
+    """Test that translated unit."""
+
+    with patch(
+        "homeassistant.helpers.service.translation.async_get_translations",
+        return_value={
+            "component.test.entity.number.test_translation_key.unit_of_measurement": "Tests"
+        },
+    ):
+        entity0 = common.MockNumberEntity(
+            name="Test",
+            native_value=123,
+            unique_id="very_unique",
+        )
+        entity0.entity_description = NumberEntityDescription(
+            "test",
+            translation_key="test_translation_key",
+            native_unit_of_measurement="bad_unit",
+        )
+        setup_test_component_platform(hass, DOMAIN, [entity0])
+
+        assert await async_setup_component(
+            hass, "number", {"number": {"platform": "test"}}
+        )
+        await hass.async_block_till_done()
+        # Setup fails so entity_id is None
+        assert entity0.entity_id is None
+
+
 def test_device_classes_aligned() -> None:
     """Make sure all sensor device classes are also available in NumberDeviceClass."""