fix: account for time passing between updates (#419)

custom_components/tesla_custom/sensor.py

@@ -521,6 +521,8 @@ def __init__(
         self._attr_device_class = SensorDeviceClass.TIMESTAMP
         self._attr_icon = "mdi:timer-plus"
         self._value: Optional[datetime] = None
+        self._last_known_value: Optional[int] = None
+        self._last_update_time: Optional[datetime] = None
 
     @property
     def native_value(self) -> Optional[datetime]:
@@ -529,8 +531,17 @@ def native_value(self) -> Optional[datetime]:
             charge_hours = 0
         else:
             charge_hours = float(self._car.time_to_full_charge)
+
+        if self._last_known_value != charge_hours:
+            self._last_known_value = charge_hours
+            self._last_update_time = dt.utcnow()
+
         if self._car.charging_state == "Charging" and charge_hours > 0:
-            new_value = dt.utcnow() + timedelta(hours=charge_hours)
+            new_value = (
+                dt.utcnow()
+                + timedelta(hours=charge_hours)
+                - (dt.utcnow() - self._last_update_time)
+            )
             if self._value is None or (new_value - self._value).total_seconds() >= 60:
                 self._value = new_value
         if self._car.charging_state in ["Charging", "Complete"]:

tests/test_sensor.py

@@ -261,6 +261,15 @@ async def test_time_charge_complete_charging(
     assert state.attributes.get(ATTR_DEVICE_CLASS) == SensorDeviceClass.TIMESTAMP
     assert state.attributes.get(ATTR_STATE_CLASS) is None
 
+    mock_timetravel = mock_now + timedelta(minutes=2)
+    monkeypatch.setattr(dt, "utcnow", lambda: mock_timetravel)
+
+    state = hass.states.get("sensor.my_model_s_time_charge_complete")
+    charge_complete = mock_now + timedelta(
+        hours=float(car_mock_data.VEHICLE_DATA["charge_state"]["time_to_full_charge"])
+    )
+    charge_complete_str = datetime.strftime(charge_complete, "%Y-%m-%dT%H:%M:%S+00:00")
+
 
 async def test_time_charge_completed(hass: HomeAssistant) -> None:
     """Tests time charge complete is the correct value."""