Give the measurements a state class, so they build long-term statistics

Temperatures had a device class and a unit but no state class, which is what
Home Assistant needs to keep statistics. They were recorded as history and
would have vanished with the recorder's retention -- ten days by default --
without ever becoming a trend.

The temperatures and the two supply rails are measurements and now say so. The
rest stay plain states: a firmware revision and a mode number are numbers, but
their average is meaningless and would only clutter the statistics.

Author: cgehring-blip

README.md

@@ -56,6 +56,11 @@ and a generic writable entity over that surface would be a foot-gun.
 Values are **pushed**: once subscribed, the appliance reports changes as they
 happen, including changes made at the panel or from the app.
 
+Temperatures and the supply rails carry a state class, so they build long-term
+statistics rather than disappearing with the recorder's retention. The rest are
+states, not measurements — averaging a firmware revision or a mode number says
+nothing — so they appear in history only.
+
 ## Installation
 
 [![Open your Home Assistant instance and open a repository inside the Home Assistant Community Store.](https://my.home-assistant.io/badges/hacs_repository.svg)](https://my.home-assistant.io/redirect/hacs_repository/?owner=omc69&repository=Truma-Aventa2-HomeAssistant-Integration&category=integration)

custom_components/truma_aventa/manifest.json

@@ -30,5 +30,5 @@
     "bleak-retry-connector>=3.5.0",
     "cbor2>=5.6.0"
   ],
-  "version": "0.9.7"
+  "version": "0.9.8"
 }

custom_components/truma_aventa/sensor.py

@@ -20,8 +20,16 @@
 import re
 from typing import Any, Final
 
-from homeassistant.components.sensor import SensorDeviceClass, SensorEntity
-from homeassistant.const import EntityCategory, UnitOfTemperature
+from homeassistant.components.sensor import (
+    SensorDeviceClass,
+    SensorEntity,
+    SensorStateClass,
+)
+from homeassistant.const import (
+    EntityCategory,
+    UnitOfElectricPotential,
+    UnitOfTemperature,
+)
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.device_registry import DeviceInfo
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
@@ -47,6 +55,9 @@
     }
 )
 
+#: Supply rails, reported in millivolts.
+_VOLTAGES: Final = frozenset({"Eol.Vcc12", "Eol.Vcc5"})
+
 #: Our own pairing identity, which the bus reports back to us like any other
 #: parameter. It says nothing about the appliance and it is the one value here
 #: worth keeping out of a state machine, so it is left out.
@@ -172,6 +183,16 @@ def __init__(
             self._attr_device_class = SensorDeviceClass.TEMPERATURE
             self._attr_native_unit_of_measurement = UnitOfTemperature.CELSIUS
             self._attr_suggested_display_precision = 1
+            # Without a state class there are no long-term statistics, and a
+            # temperature is gone with the recorder's retention rather than
+            # becoming a year's trend.
+            self._attr_state_class = SensorStateClass.MEASUREMENT
+        elif parameter in _VOLTAGES:
+            self._attr_device_class = SensorDeviceClass.VOLTAGE
+            self._attr_native_unit_of_measurement = (
+                UnitOfElectricPotential.MILLIVOLT
+            )
+            self._attr_state_class = SensorStateClass.MEASUREMENT
         self._attr_device_info = self._build_device_info(coordinator, identity)
 
     def _build_device_info(

tests/test_sensor.py

@@ -17,6 +17,8 @@
 
 sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
 
+from homeassistant.components.sensor import SensorStateClass
+
 from custom_components.truma_aventa.const import DOMAIN
 from custom_components.truma_aventa.sensor import (
     TrumaParameterSensor,
@@ -34,6 +36,8 @@
     "0101/Identify.SwMaj": 3,
     "0101/Identify.SwMin": 5,
     "0101/Temperature.Internal": 249,
+    "0101/Eol.Vcc12": 12040,
+    "0101/Identify.SwBgFx": 26,
     "0200/Identify.UniqueID": "0a69818a.device.id.ii.inetx",
     "0200/RoomClimate.TgtTemp": 220,
     # The air conditioning answers on two addresses and carries its name on
@@ -201,3 +205,26 @@ def test_a_name_on_a_later_address_still_counts(coordinator: _Coordinator) -> No
     sensor = _sensor(coordinator, "AirCooling.Temp")
     assert sensor.device_info["name"] == "Aventa comfort 2. G"
     assert sensor.name == "AirCooling Temp"
+
+
+# --- long-term statistics --------------------------------------------------
+
+
+def test_a_temperature_produces_statistics(coordinator: _Coordinator) -> None:
+    """Without a state class there is history for ten days and nothing after."""
+    sensor = _sensor(coordinator, "Temperature.Internal")
+    assert sensor.state_class is SensorStateClass.MEASUREMENT
+
+
+def test_a_supply_rail_produces_statistics(coordinator: _Coordinator) -> None:
+    """The rails are millivolts and worth a trend."""
+    sensor = _sensor(coordinator, "Eol.Vcc12")
+    assert sensor.state_class is SensorStateClass.MEASUREMENT
+    assert sensor.native_value == 12040
+
+
+def test_a_number_that_is_not_a_measurement_gets_no_state_class(
+    coordinator: _Coordinator,
+) -> None:
+    """A firmware revision is numeric and averaging it means nothing."""
+    assert _sensor(coordinator, "Identify.SwBgFx").state_class is None