Calculate _attr_native_value when no restore state and appliance is running in Whirlpool

homeassistant/components/whirlpool/sensor.py

@@ -256,6 +256,8 @@ def __init__(
         )
         self._attr_has_entity_name = True
         self._attr_unique_id = f"{said}-{description.key}"
+        if self._attr_native_value is None:
+            self._attr_native_value = utcnow()
 
     async def async_added_to_hass(self) -> None:
         """Connect washer/dryer to the cloud."""

tests/components/whirlpool/test_sensor.py

@@ -17,7 +17,7 @@ async def update_sensor_state(
     hass: HomeAssistant,
     entity_id: str,
     mock_sensor_api_instance: MagicMock,
-) -> None:
+) -> State:
     """Simulate an update trigger from the API."""
 
     for call in mock_sensor_api_instance.register_attr_callback.call_args_list:
@@ -299,6 +299,20 @@ async def test_restore_state(
     assert state.state == thetimestamp.isoformat()
 
 
+async def test_no_restore_state(
+    hass: HomeAssistant,
+    mock_sensor_api_instances: MagicMock,
+    mock_sensor1_api: MagicMock,
+) -> None:
+    """Test sensor restore state with no restore."""
+    # create and add entry
+    entity_id = "sensor.washer_end_time"
+    await init_integration(hass)
+    # restore from cache
+    state = hass.states.get(entity_id)
+    state.state = datetime.now().isoformat()
+
+
 async def test_callback(
     hass: HomeAssistant,
     mock_sensor_api_instances: MagicMock,