Auto select thermostat preset when selecting temperature

homeassistant/components/generic_thermostat/climate.py

@@ -268,6 +268,7 @@ def __init__(
         else:
             self._attr_preset_modes = [PRESET_NONE]
         self._presets = presets
+        self._presets_inv = {v: k for k, v in presets.items()}
 
     async def async_added_to_hass(self) -> None:
         """Run when entity about to be added."""
@@ -421,6 +422,7 @@ async def async_set_temperature(self, **kwargs: Any) -> None:
         """Set new target temperature."""
         if (temperature := kwargs.get(ATTR_TEMPERATURE)) is None:
             return
+        self._attr_preset_mode = self._presets_inv.get(temperature, PRESET_NONE)
         self._target_temp = temperature
         await self._async_control_heating(force=True)
         self.async_write_ha_state()

tests/components/generic_thermostat/test_climate.py

@@ -319,6 +319,20 @@ async def test_set_target_temp(hass: HomeAssistant) -> None:
     assert state.attributes.get("temperature") == 30.0
 
 
+@pytest.mark.usefixtures("setup_comp_2")
+async def test_set_target_temp_change_preset(hass: HomeAssistant) -> None:
+    """Test the setting of the target temperature.
+
+    Verify that preset is changed.
+    """
+    await common.async_set_temperature(hass, 30)
+    state = hass.states.get(ENTITY)
+    assert state.attributes.get("preset_mode") == PRESET_NONE
+    await common.async_set_temperature(hass, 20)
+    state = hass.states.get(ENTITY)
+    assert state.attributes.get("preset_mode") == PRESET_COMFORT
+
+
 @pytest.mark.parametrize(
     ("preset", "temp"),
     [