Print expected device class units in error log (#86125)

homeassistant/components/sensor/__init__.py

@@ -665,6 +665,7 @@ class SensorEntity(Entity):
                 (
                     "Entity %s (%s) is using native unit of measurement '%s' which "
                     "is not a valid unit for the device class ('%s') it is using; "
+                    "expected one of %s; "
                     "Please update your configuration if your entity is manually "
                     "configured, otherwise %s"
                 ),
@@ -672,6 +673,7 @@ class SensorEntity(Entity):
                 type(self),
                 native_unit_of_measurement,
                 device_class,
+                [str(unit) if unit else "no unit of measurement" for unit in units],
                 report_issue,
             )
 

tests/components/sensor/test_init.py

@@ -9,7 +9,11 @@ import pytest
 from pytest import approx
 
 from homeassistant.components.number import NumberDeviceClass
-from homeassistant.components.sensor import SensorDeviceClass, SensorStateClass
+from homeassistant.components.sensor import (
+    DEVICE_CLASS_UNITS,
+    SensorDeviceClass,
+    SensorStateClass,
+)
 from homeassistant.const import (
     ATTR_UNIT_OF_MEASUREMENT,
     PERCENTAGE,
@@ -1403,13 +1407,17 @@ async def test_device_classes_with_invalid_unit_of_measurement(
         device_class=device_class,
         native_unit_of_measurement="INVALID!",
     )
-
+    units = [
+        str(unit) if unit else "no unit of measurement"
+        for unit in DEVICE_CLASS_UNITS.get(device_class, set())
+    ]
     assert await async_setup_component(hass, "sensor", {"sensor": {"platform": "test"}})
     await hass.async_block_till_done()
 
     assert (
         "is using native unit of measurement 'INVALID!' which is not a valid "
-        f"unit for the device class ('{device_class}') it is using"
+        f"unit for the device class ('{device_class}') it is using; "
+        f"expected one of {units}"
     ) in caplog.text