Fix lifx light strips when color zones are not initially populated (#92487)

fixes #92456

homeassistant/components/lifx/coordinator.py

@@ -205,13 +205,20 @@ class LIFXUpdateCoordinator(DataUpdateCoordinator[None]):
             methods, DEFAULT_ATTEMPTS, OVERALL_TIMEOUT
         )
 
+    def get_number_of_zones(self) -> int:
+        """Return the number of zones.
+
+        If the number of zones is not yet populated, return 0
+        """
+        return len(self.device.color_zones) if self.device.color_zones else 0
+
     @callback
     def _async_build_color_zones_update_requests(self) -> list[Callable]:
         """Build a color zones update request."""
         device = self.device
         return [
             partial(device.get_color_zones, start_index=zone)
-            for zone in range(0, len(device.color_zones), 8)
+            for zone in range(0, self.get_number_of_zones(), 8)
         ]
 
     async def _async_update_data(self) -> None:
@@ -224,7 +231,7 @@ class LIFXUpdateCoordinator(DataUpdateCoordinator[None]):
         ):
             await self._async_populate_device_info()
 
-        num_zones = len(device.color_zones) if device.color_zones is not None else 0
+        num_zones = self.get_number_of_zones()
         features = lifx_features(self.device)
         is_extended_multizone = features["extended_multizone"]
         is_legacy_multizone = not is_extended_multizone and features["multizone"]
@@ -256,7 +263,7 @@ class LIFXUpdateCoordinator(DataUpdateCoordinator[None]):
 
         if is_extended_multizone or is_legacy_multizone:
             self.active_effect = FirmwareEffect[self.device.effect.get("effect", "OFF")]
-        if is_legacy_multizone and num_zones != len(device.color_zones):
+        if is_legacy_multizone and num_zones != self.get_number_of_zones():
             # The number of zones has changed so we need
             # to update the zones again. This happens rarely.
             await self.async_get_color_zones()

homeassistant/components/lifx/light.py

@@ -391,7 +391,7 @@ class LIFXMultiZone(LIFXColor):
         """Send a color change to the bulb."""
         bulb = self.bulb
         color_zones = bulb.color_zones
-        num_zones = len(color_zones)
+        num_zones = self.coordinator.get_number_of_zones()
 
         # Zone brightness is not reported when powered off
         if not self.is_on and hsbk[HSBK_BRIGHTNESS] is None:

tests/components/lifx/test_light.py

@@ -36,6 +36,7 @@ from homeassistant.components.light import (
     ATTR_TRANSITION,
     ATTR_XY_COLOR,
     DOMAIN as LIGHT_DOMAIN,
+    SERVICE_TURN_ON,
     ColorMode,
 )
 from homeassistant.const import (
@@ -1741,3 +1742,46 @@ async def test_set_hev_cycle_state_fails_for_color_bulb(hass: HomeAssistant) ->
             {ATTR_ENTITY_ID: entity_id, ATTR_POWER: True},
             blocking=True,
         )
+
+
+async def test_light_strip_zones_not_populated_yet(hass: HomeAssistant) -> None:
+    """Test a light strip were zones are not populated initially."""
+    already_migrated_config_entry = MockConfigEntry(
+        domain=DOMAIN, data={CONF_HOST: "127.0.0.1"}, unique_id=SERIAL
+    )
+    already_migrated_config_entry.add_to_hass(hass)
+    bulb = _mocked_light_strip()
+    bulb.power_level = 65535
+    bulb.color_zones = None
+    bulb.color = [65535, 65535, 65535, 65535]
+    with _patch_discovery(device=bulb), _patch_config_flow_try_connect(
+        device=bulb
+    ), _patch_device(device=bulb):
+        await async_setup_component(hass, lifx.DOMAIN, {lifx.DOMAIN: {}})
+        await hass.async_block_till_done()
+
+    entity_id = "light.my_bulb"
+
+    state = hass.states.get(entity_id)
+    assert state.state == "on"
+    attributes = state.attributes
+    assert attributes[ATTR_BRIGHTNESS] == 255
+    assert attributes[ATTR_COLOR_MODE] == ColorMode.HS
+    assert attributes[ATTR_SUPPORTED_COLOR_MODES] == [
+        ColorMode.COLOR_TEMP,
+        ColorMode.HS,
+    ]
+    assert attributes[ATTR_HS_COLOR] == (360.0, 100.0)
+    assert attributes[ATTR_RGB_COLOR] == (255, 0, 0)
+    assert attributes[ATTR_XY_COLOR] == (0.701, 0.299)
+
+    await hass.services.async_call(
+        LIGHT_DOMAIN, SERVICE_TURN_ON, {ATTR_ENTITY_ID: entity_id}, blocking=True
+    )
+    assert bulb.set_power.calls[0][0][0] is True
+    bulb.set_power.reset_mock()
+
+    async_fire_time_changed(hass, dt_util.utcnow() + timedelta(seconds=30))
+    await hass.async_block_till_done()
+    state = hass.states.get(entity_id)
+    assert state.state == STATE_ON