Add support for state_class to MQTT sensor (#50927)

homeassistant/components/mqtt/abbreviations.py

@@ -160,6 +160,7 @@ ABBREVIATIONS = {
     "spd_val_tpl": "speed_value_template",
     "spds": "speeds",
     "src_type": "source_type",
+    "stat_cla": "state_class",
     "stat_clsd": "state_closed",
     "stat_closing": "state_closing",
     "stat_off": "state_off",

homeassistant/components/mqtt/sensor.py

@@ -7,7 +7,11 @@ import functools
 import voluptuous as vol
 
 from homeassistant.components import sensor
-from homeassistant.components.sensor import DEVICE_CLASSES_SCHEMA, SensorEntity
+from homeassistant.components.sensor import (
+    DEVICE_CLASSES_SCHEMA,
+    STATE_CLASSES_SCHEMA,
+    SensorEntity,
+)
 from homeassistant.const import (
     CONF_DEVICE_CLASS,
     CONF_FORCE_UPDATE,
@@ -33,6 +37,7 @@ from .mixins import (
 )
 
 CONF_EXPIRE_AFTER = "expire_after"
+CONF_STATE_CLASS = "state_class"
 
 DEFAULT_NAME = "MQTT Sensor"
 DEFAULT_FORCE_UPDATE = False
@@ -42,6 +47,7 @@ PLATFORM_SCHEMA = mqtt.MQTT_RO_PLATFORM_SCHEMA.extend(
         vol.Optional(CONF_EXPIRE_AFTER): cv.positive_int,
         vol.Optional(CONF_FORCE_UPDATE, default=DEFAULT_FORCE_UPDATE): cv.boolean,
         vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
+        vol.Optional(CONF_STATE_CLASS): STATE_CLASSES_SCHEMA,
         vol.Optional(CONF_UNIT_OF_MEASUREMENT): cv.string,
     }
 ).extend(MQTT_ENTITY_COMMON_SCHEMA.schema)
@@ -173,6 +179,11 @@ class MqttSensor(MqttEntity, SensorEntity):
         """Return the device class of the sensor."""
         return self._config.get(CONF_DEVICE_CLASS)
 
+    @property
+    def state_class(self) -> str | None:
+        """Return the state class of the sensor."""
+        return self._config.get(CONF_STATE_CLASS)
+
     @property
     def available(self) -> bool:
         """Return true if the device is available and value has not expired."""

tests/components/mqtt/test_sensor.py

@@ -381,6 +381,51 @@ async def test_valid_device_class(hass, mqtt_mock):
     assert "device_class" not in state.attributes
 
 
+async def test_invalid_state_class(hass, mqtt_mock):
+    """Test state_class option with invalid value."""
+    assert await async_setup_component(
+        hass,
+        sensor.DOMAIN,
+        {
+            sensor.DOMAIN: {
+                "platform": "mqtt",
+                "name": "test",
+                "state_topic": "test-topic",
+                "state_class": "foobarnotreal",
+            }
+        },
+    )
+    await hass.async_block_till_done()
+
+    state = hass.states.get("sensor.test")
+    assert state is None
+
+
+async def test_valid_state_class(hass, mqtt_mock):
+    """Test state_class option with valid values."""
+    assert await async_setup_component(
+        hass,
+        "sensor",
+        {
+            "sensor": [
+                {
+                    "platform": "mqtt",
+                    "name": "Test 1",
+                    "state_topic": "test-topic",
+                    "state_class": "measurement",
+                },
+                {"platform": "mqtt", "name": "Test 2", "state_topic": "test-topic"},
+            ]
+        },
+    )
+    await hass.async_block_till_done()
+
+    state = hass.states.get("sensor.test_1")
+    assert state.attributes["state_class"] == "measurement"
+    state = hass.states.get("sensor.test_2")
+    assert "state_class" not in state.attributes
+
+
 async def test_setting_attribute_via_mqtt_json_message(hass, mqtt_mock):
     """Test the setting of attribute via MQTT with JSON payload."""
     await help_test_setting_attribute_via_mqtt_json_message(