diff --git a/homeassistant/components/derivative/sensor.py b/homeassistant/components/derivative/sensor.py index 36719b43ccb..be27201bda9 100644 --- a/homeassistant/components/derivative/sensor.py +++ b/homeassistant/components/derivative/sensor.py @@ -10,9 +10,11 @@ from typing import TYPE_CHECKING import voluptuous as vol from homeassistant.components.sensor import ( + ATTR_STATE_CLASS, PLATFORM_SCHEMA as SENSOR_PLATFORM_SCHEMA, RestoreSensor, SensorEntity, + SensorStateClass, ) from homeassistant.config_entries import ConfigEntry from homeassistant.const import ( @@ -238,6 +240,16 @@ class DerivativeSensor(RestoreSensor, SensorEntity): except AssertionError as err: _LOGGER.error("Could not calculate derivative: %s", err) + # For total inreasing sensors, the value is expected to continuously increase. + # A negative derivative for a total increasing sensor likely indicates the + # sensor has been reset. To prevent inaccurate data, discard this sample. + if ( + new_state.attributes.get(ATTR_STATE_CLASS) + == SensorStateClass.TOTAL_INCREASING + and new_derivative < 0 + ): + return + # add latest derivative to the window list self._state_list.append( (old_state.last_updated, new_state.last_updated, new_derivative) diff --git a/tests/components/derivative/test_sensor.py b/tests/components/derivative/test_sensor.py index 3646340cac3..4a4d8519b25 100644 --- a/tests/components/derivative/test_sensor.py +++ b/tests/components/derivative/test_sensor.py @@ -8,6 +8,7 @@ from typing import Any from freezegun import freeze_time from homeassistant.components.derivative.const import DOMAIN +from homeassistant.components.sensor import ATTR_STATE_CLASS, SensorStateClass from homeassistant.const import UnitOfPower, UnitOfTime from homeassistant.core import HomeAssistant, State from homeassistant.helpers import device_registry as dr, entity_registry as er @@ -354,6 +355,41 @@ async def test_suffix(hass: HomeAssistant) -> None: assert round(float(state.state), config["sensor"]["round"]) == 0.0 +async def test_total_increasing_reset(hass: HomeAssistant) -> None: + """Test derivative sensor state with total_increasing sensor input where it should ignore the reset value.""" + times = [0, 20, 30, 35, 40, 50, 60] + values = [0, 10, 30, 40, 0, 10, 40] + expected_times = [0, 20, 30, 35, 50, 60] + expected_values = ["0.00", "0.50", "2.00", "2.00", "1.00", "3.00"] + + config, entity_id = await _setup_sensor(hass, {"unit_time": UnitOfTime.SECONDS}) + + base_time = dt_util.utcnow() + actual_times = [] + actual_values = [] + with freeze_time(base_time) as freezer: + for time, value in zip(times, values, strict=False): + current_time = base_time + timedelta(seconds=time) + freezer.move_to(current_time) + hass.states.async_set( + entity_id, + value, + {ATTR_STATE_CLASS: SensorStateClass.TOTAL_INCREASING}, + force_update=True, + ) + await hass.async_block_till_done() + + state = hass.states.get("sensor.power") + assert state is not None + + if state.last_reported == current_time: + actual_times.append(time) + actual_values.append(state.state) + + assert actual_times == expected_times + assert actual_values == expected_values + + async def test_device_id( hass: HomeAssistant, entity_registry: er.EntityRegistry,