Fix entity removal leaks in plant (#183865)

homeassistant/components/plant/__init__.py

@@ -303,8 +303,10 @@ class Plant(Entity):
             )
             self.async_write_ha_state()
 
-        async_track_state_change_event(
-            self.hass, list(self._sensormap), self._state_changed_event
+        self.async_on_remove(
+            async_track_state_change_event(
+                self.hass, list(self._sensormap), self._state_changed_event
+            )
         )
 
         for entity_id in self._sensormap:

tests/components/plant/test_init.py

@@ -13,6 +13,7 @@ from homeassistant.const import (
     UnitOfConductivity,
 )
 from homeassistant.core import HomeAssistant, State
+from homeassistant.helpers.entity_component import DATA_INSTANCES
 from homeassistant.setup import async_setup_component
 
 from tests.components.recorder.common import async_wait_recording_done
@@ -113,6 +114,27 @@ async def test_update_states(hass: HomeAssistant) -> None:
     assert state.attributes[plant.READING_MOISTURE] == 5
 
 
+async def test_state_tracking_stops_after_removal(hass: HomeAssistant) -> None:
+    """Test a removed plant no longer processes sensor state changes."""
+    plant_name = "some_plant"
+    entity_id = f"plant.{plant_name}"
+    assert await async_setup_component(
+        hass, plant.DOMAIN, {plant.DOMAIN: {plant_name: GOOD_CONFIG}}
+    )
+    hass.states.async_set(MOISTURE_ENTITY, 50)
+    await hass.async_block_till_done()
+    entity = hass.data[DATA_INSTANCES][plant.DOMAIN].get_entity(entity_id)
+    assert entity.extra_state_attributes[plant.READING_MOISTURE] == 50
+
+    await entity.async_remove()
+    assert hass.states.get(entity_id) is None
+
+    hass.states.async_set(MOISTURE_ENTITY, 5)
+    await hass.async_block_till_done()
+    assert entity.extra_state_attributes[plant.READING_MOISTURE] == 50
+    assert hass.states.get(entity_id) is None
+
+
 async def test_unavailable_state(hass: HomeAssistant) -> None:
     """Test updating the state with unavailable.