Fix utility_meter startup (#69064)

homeassistant/components/utility_meter/sensor.py

@@ -20,7 +20,6 @@ from homeassistant.const import (
     CONF_NAME,
     ENERGY_KILO_WATT_HOUR,
     ENERGY_WATT_HOUR,
-    EVENT_HOMEASSISTANT_START,
     STATE_UNAVAILABLE,
     STATE_UNKNOWN,
 )
@@ -33,6 +32,7 @@ from homeassistant.helpers.event import (
     async_track_state_change_event,
 )
 from homeassistant.helpers.restore_state import RestoreEntity
+from homeassistant.helpers.start import async_at_start
 from homeassistant.helpers.template import is_number
 from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType
 import homeassistant.util.dt as dt_util
@@ -426,6 +426,10 @@ class UtilityMeterSensor(RestoreEntity, SensorEntity):
                 )
 
                 tariff_entity_state = self.hass.states.get(self._tariff_entity)
+                if not tariff_entity_state:
+                    # The utility meter is not yet added
+                    return
+
                 self._change_status(tariff_entity_state.state)
                 return
 
@@ -439,9 +443,7 @@ class UtilityMeterSensor(RestoreEntity, SensorEntity):
                 self.hass, [self._sensor_source_id], self.async_reading
             )
 
-        self.hass.bus.async_listen_once(
-            EVENT_HOMEASSISTANT_START, async_source_tracking
-        )
+        async_at_start(self.hass, async_source_tracking)
 
     @property
     def name(self):

tests/components/utility_meter/test_sensor.py

@@ -37,7 +37,7 @@ from homeassistant.const import (
     STATE_UNAVAILABLE,
     STATE_UNKNOWN,
 )
-from homeassistant.core import State
+from homeassistant.core import CoreState, State
 from homeassistant.setup import async_setup_component
 import homeassistant.util.dt as dt_util
 
@@ -418,6 +418,9 @@ async def test_device_class(hass, yaml_config, config_entry_configs):
 )
 async def test_restore_state(hass, yaml_config, config_entry_config):
     """Test utility sensor restore state."""
+    # Home assistant is not runnit yet
+    hass.state = CoreState.not_running
+
     last_reset = "2020-12-21T00:00:00.013073+00:00"
     mock_restore_cache(
         hass,
@@ -668,6 +671,9 @@ async def test_non_net_consumption(hass, yaml_config, config_entry_config, caplo
 )
 async def test_delta_values(hass, yaml_config, config_entry_config, caplog):
     """Test utility meter "delta_values" mode."""
+    # Home assistant is not runnit yet
+    hass.state = CoreState.not_running
+
     now = dt_util.utcnow()
     with alter_time(now):
         if yaml_config: