Allow equivalent sensor units for MQTT sensor

homeassistant/components/mqtt/sensor.py

@@ -21,6 +21,7 @@ from homeassistant.components.sensor import (
     SensorExtraStoredData,
     SensorStateClass,
 )
+from homeassistant.components.sensor.recorder import EQUIVALENT_UNITS
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import (
     CONF_DEVICE_CLASS,
@@ -132,6 +133,10 @@ def validate_sensor_state_and_device_class_config(config: ConfigType) -> ConfigT
     ) is None:
         return config
 
+    if unit_of_measurement in EQUIVALENT_UNITS:
+        unit_of_measurement = config[CONF_UNIT_OF_MEASUREMENT] = EQUIVALENT_UNITS[
+            unit_of_measurement
+        ]
     if (
         device_class in DEVICE_CLASS_UNITS
         and unit_of_measurement not in DEVICE_CLASS_UNITS[device_class]

tests/components/mqtt/test_sensor.py

@@ -906,6 +906,100 @@ async def test_invalid_unit_of_measurement(
     assert state is None
 
 
+@pytest.mark.parametrize(
+    "hass_config",
+    [
+        {
+            mqtt.DOMAIN: {
+                sensor.DOMAIN: {
+                    "name": "test",
+                    "state_topic": "test-topic",
+                    "device_class": "voltage",
+                    "unit_of_measurement": "\u00b5V",
+                }
+            }
+        }
+    ],
+)
+async def test_device_class_with_equivalent_unit_of_measurement_received(
+    hass: HomeAssistant,
+    mqtt_mock_entry: MqttMockHAClientGenerator,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test device_class with equivalent unit of measurement."""
+    assert await mqtt_mock_entry()
+    async_fire_mqtt_message(hass, "test-topic", "100")
+    await hass.async_block_till_done()
+    state = hass.states.get("sensor.test")
+    assert state is not None
+    assert state.state == "100"
+
+    caplog.clear()
+
+    discovery_payload = {
+        "name": "bla",
+        "state_topic": "test-topic2",
+        "device_class": "voltage",
+        "unit_of_measurement": "\u00b5V",
+    }
+    # Now discover an invalid sensor
+    async_fire_mqtt_message(
+        hass, "homeassistant/sensor/bla/config", json.dumps(discovery_payload)
+    )
+    await hass.async_block_till_done()
+    async_fire_mqtt_message(hass, "test-topic2", "21")
+    await hass.async_block_till_done()
+    state = hass.states.get("sensor.bla")
+    assert state is not None
+    assert state.state == "21"
+
+
+@pytest.mark.parametrize(
+    "hass_config",
+    [
+        {
+            mqtt.DOMAIN: {
+                sensor.DOMAIN: {
+                    "name": "test",
+                    "state_topic": "test-topic",
+                    "unit_of_measurement": "\u00b5V",
+                }
+            }
+        }
+    ],
+)
+async def test_equivalent_unit_of_measurement_received_without_device_class(
+    hass: HomeAssistant,
+    mqtt_mock_entry: MqttMockHAClientGenerator,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test device_class with equivalent unit of measurement."""
+    assert await mqtt_mock_entry()
+    async_fire_mqtt_message(hass, "test-topic", "100")
+    await hass.async_block_till_done()
+    state = hass.states.get("sensor.test")
+    assert state is not None
+    assert state.state == "100"
+
+    caplog.clear()
+
+    discovery_payload = {
+        "name": "bla",
+        "state_topic": "test-topic2",
+        "unit_of_measurement": "\u00b5V",
+    }
+    # Now discover an invalid sensor
+    async_fire_mqtt_message(
+        hass, "homeassistant/sensor/bla/config", json.dumps(discovery_payload)
+    )
+    await hass.async_block_till_done()
+    async_fire_mqtt_message(hass, "test-topic2", "21")
+    await hass.async_block_till_done()
+    state = hass.states.get("sensor.bla")
+    assert state is not None
+    assert state.state == "21"
+
+
 @pytest.mark.parametrize(
     "hass_config",
     [