Fix zha illuminance measured value mapping (#108547)

homeassistant/components/zha/sensor.py

@@ -483,8 +483,12 @@ class Illuminance(Sensor):
     _attr_state_class: SensorStateClass = SensorStateClass.MEASUREMENT
     _attr_native_unit_of_measurement = LIGHT_LUX
 
-    def formatter(self, value: int) -> int:
+    def formatter(self, value: int) -> int | None:
         """Convert illumination data."""
+        if value == 0:
+            return 0
+        if value == 0xFFFF:
+            return None
         return round(pow(10, ((value - 1) / 10000)))
 
 

tests/components/zha/test_sensor.py

@@ -136,6 +136,12 @@ async def async_test_illuminance(hass, cluster, entity_id):
     await send_attributes_report(hass, cluster, {1: 1, 0: 10, 2: 20})
     assert_state(hass, entity_id, "1", LIGHT_LUX)
 
+    await send_attributes_report(hass, cluster, {1: 0, 0: 0, 2: 20})
+    assert_state(hass, entity_id, "0", LIGHT_LUX)
+
+    await send_attributes_report(hass, cluster, {1: 0, 0: 0xFFFF, 2: 20})
+    assert_state(hass, entity_id, "unknown", LIGHT_LUX)
+
 
 async def async_test_metering(hass, cluster, entity_id):
     """Test Smart Energy metering sensor."""