[homekit] Sort optional characteristics before adding them to the service

So that they'll always be added in a consistent order. Otherwise we might
accidentally change the order (and thus the IID) of a characteristic, but
not actually detect that it's different and signal Home to reload accessory
structures.

Signed-off-by: Cody Cutrer <[email protected]>

Author: ccutrer

bundles/org.openhab.io.homekit/src/main/java/org/openhab/io/homekit/internal/accessories/AbstractHomekitAccessoryImpl.java

@@ -242,19 +242,20 @@ public void addService(Service service) {
         services.add(service);
 
         var serviceClass = service.getClass();
-        rawCharacteristics.values().forEach(characteristic -> {
-            // belongs on the accessory information service
-            if (characteristic.getClass() == NameCharacteristic.class) {
-                return;
-            }
-            try {
-                // if the service supports adding this characteristic as optional, add it!
-                serviceClass.getMethod("addOptionalCharacteristic", characteristic.getClass()).invoke(service,
-                        characteristic);
-            } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
-                // the service doesn't support this optional characteristic; ignore it
-            }
-        });
+        rawCharacteristics.values().stream().sorted((lhs, rhs) -> lhs.getType().compareTo(rhs.getType()))
+                .forEach(characteristic -> {
+                    // belongs on the accessory information service
+                    if (characteristic.getClass() == NameCharacteristic.class) {
+                        return;
+                    }
+                    try {
+                        // if the service supports adding this characteristic as optional, add it!
+                        serviceClass.getMethod("addOptionalCharacteristic", characteristic.getClass()).invoke(service,
+                                characteristic);
+                    } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+                        // the service doesn't support this optional characteristic; ignore it
+                    }
+                });
     }
 
     protected HomekitAccessoryUpdater getUpdater() {