Leave a SwitchBot air purifier without a preset it does not report (#180560)

homeassistant/components/switchbot_cloud/fan.py

@@ -137,6 +137,11 @@ class SwitchBotCloudFan(SwitchBotCloudEntity, FanEntity):
         await self.coordinator.async_request_refresh()
 
 
+_AIR_PURIFIER_PRESET_MODES = {
+    mode.value: mode.name.lower() for mode in AirPurifierModeV2
+}
+
+
 class SwitchBotAirPurifierEntity(SwitchBotCloudEntity, FanEntity):
     """Representation of a Switchbot air purifier."""
 
@@ -164,9 +169,9 @@ class SwitchBotAirPurifierEntity(SwitchBotCloudEntity, FanEntity):
             return
 
         self._attr_is_on = self.coordinator.data.get("power") == STATE_ON.upper()
-        mode = self.coordinator.data.get("mode")
-        self._attr_preset_mode = (
-            AirPurifierModeV2(mode).name.lower() if mode is not None else None
+        # An unplugged purifier reports a mode of its own that is none of these
+        self._attr_preset_mode = _AIR_PURIFIER_PRESET_MODES.get(
+            self.coordinator.data.get("mode")
         )
 
     @override

tests/components/switchbot_cloud/test_fan.py

@@ -308,6 +308,29 @@ async def test_air_purifier(
     await snapshot_platform(hass, entity_registry, snapshot, entry.entry_id)
 
 
+async def test_air_purifier_unknown_mode(
+    hass: HomeAssistant,
+    mock_list_devices: AsyncMock,
+    mock_get_status: AsyncMock,
+) -> None:
+    """Test an air purifier reporting a mode that is not one of its presets.
+
+    An unplugged purifier reports mode 0, which no preset maps to.
+    """
+    mock_list_devices.return_value = [AIR_PURIFIER_INFO]
+    status = await async_load_json_object_fixture(
+        hass, "air_purifier_status.json", DOMAIN
+    )
+    mock_get_status.return_value = {**status, "power": "OFF", "mode": 0}
+
+    with patch("homeassistant.components.switchbot_cloud.PLATFORMS", [Platform.FAN]):
+        await configure_integration(hass)
+
+    state = hass.states.get("fan.air_purifier_1")
+    assert state.state == STATE_OFF
+    assert state.attributes[ATTR_PRESET_MODE] is None
+
+
 @pytest.mark.parametrize(
     ("service", "service_data", "expected_call_args"),
     [