Hoist ATTR_LAST_RESET from utility_meter to SensorEntity (#50757)

homeassistant/components/sensor/__init__.py

@@ -2,9 +2,9 @@
 from __future__ import annotations
 
 from collections.abc import Mapping
-from datetime import timedelta
+from datetime import datetime, timedelta
 import logging
-from typing import Any, cast
+from typing import Any, cast, final
 
 import voluptuous as vol
 
@@ -36,6 +36,7 @@ from homeassistant.helpers.typing import ConfigType
 
 _LOGGER = logging.getLogger(__name__)
 
+ATTR_LAST_RESET = "last_reset"
 ATTR_STATE_CLASS = "state_class"
 
 DOMAIN = "sensor"
@@ -100,10 +101,24 @@ class SensorEntity(Entity):
         """Return the state class of this entity, from STATE_CLASSES, if any."""
         return None
 
+    @property
+    def last_reset(self) -> datetime | None:
+        """Return the time when the sensor was last reset, if any."""
+        return None
+
     @property
     def capability_attributes(self) -> Mapping[str, Any] | None:
         """Return the capability attributes."""
-        if self.state_class:
-            return {ATTR_STATE_CLASS: self.state_class}
+        if state_class := self.state_class:
+            return {ATTR_STATE_CLASS: state_class}
+
+        return None
+
+    @final
+    @property
+    def state_attributes(self) -> dict[str, Any] | None:
+        """Return state attributes."""
+        if last_reset := self.last_reset:
+            return {ATTR_LAST_RESET: last_reset}
 
         return None

homeassistant/components/utility_meter/sensor.py

@@ -5,7 +5,7 @@ import logging
 
 import voluptuous as vol
 
-from homeassistant.components.sensor import SensorEntity
+from homeassistant.components.sensor import ATTR_LAST_RESET, SensorEntity
 from homeassistant.const import (
     ATTR_UNIT_OF_MEASUREMENT,
     CONF_NAME,
@@ -51,7 +51,6 @@ ATTR_SOURCE_ID = "source"
 ATTR_STATUS = "status"
 ATTR_PERIOD = "meter_period"
 ATTR_LAST_PERIOD = "last_period"
-ATTR_LAST_RESET = "last_reset"
 ATTR_TARIFF = "tariff"
 
 ICON = "mdi:counter"
@@ -331,7 +330,6 @@ class UtilityMeterSensor(RestoreEntity, SensorEntity):
             ATTR_SOURCE_ID: self._sensor_source_id,
             ATTR_STATUS: PAUSED if self._collecting is None else COLLECTING,
             ATTR_LAST_PERIOD: self._last_period,
-            ATTR_LAST_RESET: self._last_reset,
         }
         if self._period is not None:
             state_attr[ATTR_PERIOD] = self._period
@@ -343,3 +341,8 @@ class UtilityMeterSensor(RestoreEntity, SensorEntity):
     def icon(self):
         """Return the icon to use in the frontend, if any."""
         return ICON
+
+    @property
+    def last_reset(self):
+        """Return the time when the sensor was last reset."""
+        return self._last_reset

tests/components/utility_meter/test_sensor.py

@@ -161,6 +161,7 @@ async def test_state(hass):
 
 async def test_restore_state(hass):
     """Test utility sensor restore state."""
+    last_reset = "2020-12-21T00:00:00.013073+00:00"
     config = {
         "utility_meter": {
             "energy_bill": {
@@ -177,7 +178,7 @@ async def test_restore_state(hass):
                 "3",
                 attributes={
                     ATTR_STATUS: PAUSED,
-                    ATTR_LAST_RESET: "2020-12-21T00:00:00.013073+00:00",
+                    ATTR_LAST_RESET: last_reset,
                 },
             ),
             State(
@@ -185,7 +186,7 @@ async def test_restore_state(hass):
                 "6",
                 attributes={
                     ATTR_STATUS: COLLECTING,
-                    ATTR_LAST_RESET: "2020-12-21T00:00:00.013073+00:00",
+                    ATTR_LAST_RESET: last_reset,
                 },
             ),
         ],
@@ -199,10 +200,12 @@ async def test_restore_state(hass):
     state = hass.states.get("sensor.energy_bill_onpeak")
     assert state.state == "3"
     assert state.attributes.get("status") == PAUSED
+    assert state.attributes.get("last_reset") == dt_util.parse_datetime(last_reset)
 
     state = hass.states.get("sensor.energy_bill_offpeak")
     assert state.state == "6"
     assert state.attributes.get("status") == COLLECTING
+    assert state.attributes.get("last_reset") == dt_util.parse_datetime(last_reset)
 
     # utility_meter is loaded, now set sensors according to utility_meter:
     hass.bus.async_fire(EVENT_HOMEASSISTANT_START)
@@ -304,15 +307,15 @@ def gen_config(cycle, offset=None):
 
 async def _test_self_reset(hass, config, start_time, expect_reset=True):
     """Test energy sensor self reset."""
-    assert await async_setup_component(hass, DOMAIN, config)
-    assert await async_setup_component(hass, SENSOR_DOMAIN, config)
-    await hass.async_block_till_done()
-
-    hass.bus.async_fire(EVENT_HOMEASSISTANT_START)
-    entity_id = config[DOMAIN]["energy_bill"]["source"]
-
     now = dt_util.parse_datetime(start_time)
     with alter_time(now):
+        assert await async_setup_component(hass, DOMAIN, config)
+        assert await async_setup_component(hass, SENSOR_DOMAIN, config)
+        await hass.async_block_till_done()
+
+        hass.bus.async_fire(EVENT_HOMEASSISTANT_START)
+        entity_id = config[DOMAIN]["energy_bill"]["source"]
+
         async_fire_time_changed(hass, now)
         hass.states.async_set(
             entity_id, 1, {ATTR_UNIT_OF_MEASUREMENT: ENERGY_KILO_WATT_HOUR}
@@ -345,10 +348,12 @@ async def _test_self_reset(hass, config, start_time, expect_reset=True):
     state = hass.states.get("sensor.energy_bill")
     if expect_reset:
         assert state.attributes.get("last_period") == "2"
+        assert state.attributes.get("last_reset") == now
         assert state.state == "3"
     else:
         assert state.attributes.get("last_period") == 0
         assert state.state == "5"
+        assert state.attributes.get("last_reset") == dt_util.parse_datetime(start_time)
 
 
 async def test_self_reset_quarter_hourly(hass, legacy_patchable_time):