[ECO-5426] Refactored code as per review comments

Author: sacOO7

live-objects/src/main/kotlin/io/ably/lib/objects/Helpers.kt

@@ -33,11 +33,10 @@ internal fun LiveObjectsAdapter.ensureMessageSizeWithinLimit(objectMessages: Arr
 }
 
 internal fun LiveObjectsAdapter.setChannelSerial(channelName: String, protocolMessage: ProtocolMessage) {
-  if (protocolMessage.action == ProtocolMessage.Action.`object`) {
-    val channelSerial = protocolMessage.channelSerial
-    if (channelSerial.isNullOrEmpty()) return
-    setChannelSerial(channelName, channelSerial)
-  }
+  if (protocolMessage.action != ProtocolMessage.Action.`object`) return
+  val channelSerial = protocolMessage.channelSerial
+  if (channelSerial.isNullOrEmpty()) return
+  setChannelSerial(channelName, channelSerial)
 }
 
 internal enum class ProtocolMessageFormat(private val value: String) {

live-objects/src/main/kotlin/io/ably/lib/objects/ObjectId.kt

@@ -18,8 +18,8 @@ internal class ObjectId private constructor(
     /**
      * Creates ObjectId instance from hashed object id string.
      */
-    fun fromString(objectId: String?): ObjectId {
-      if (objectId.isNullOrEmpty()) {
+    fun fromString(objectId: String): ObjectId {
+      if (objectId.isEmpty()) {
         throw objectError("Invalid object id: $objectId")
       }
 
@@ -29,8 +29,7 @@ internal class ObjectId private constructor(
         throw objectError("Invalid object id: $objectId")
       }
 
-      val typeStr = parts[0]
-      val rest = parts[1]
+      val (typeStr, rest) = parts
 
       val type = when (typeStr) {
         "map" -> ObjectType.Map

live-objects/src/main/kotlin/io/ably/lib/objects/ObjectsPool.kt

@@ -38,7 +38,6 @@ internal class ObjectsPool(
 
   /**
    * @spec RTO3a - Pool storing all live objects by object ID
-   * Note: This is the same as objectsPool property in DefaultLiveObjects.kt
    */
   private val pool = mutableMapOf<String, BaseLiveObject>()
 
@@ -88,25 +87,17 @@ internal class ObjectsPool(
    * Does not create a new root object, so the reference to the root object remains the same.
    */
   internal fun resetToInitialPool(emitUpdateEvents: Boolean) {
-    // Clear the pool first and keep the root object
-    val root = pool[ROOT_OBJECT_ID]
-    if (root != null) {
-      pool.clear()
-      set(ROOT_OBJECT_ID, root)
-
-      // this will only clear the remaining root object and emit update events
-      clearObjectsData(emitUpdateEvents)
-    } else {
-      Log.w(tag, "Root object not found in pool during reset")
-    }
+    pool.entries.removeIf { (key, _) -> key != ROOT_OBJECT_ID } // only keep the root object
+    clearObjectsData(emitUpdateEvents) // clear the root object and emit update events
   }
 
 
   /**
    * Deletes objects from the pool for which object ids are not found in the provided array of ids.
+   * Spec: RTO5c2
    */
   internal fun deleteExtraObjectIds(objectIds: MutableSet<String>) {
-    pool.entries.removeIf { (key, _) -> key !in objectIds }
+    pool.entries.removeIf { (key, _) -> key !in objectIds && key != ROOT_OBJECT_ID } // RTO5c2a - Keep root object
   }
 
   /**

live-objects/src/test/kotlin/io/ably/lib/objects/unit/ObjectIdTest.kt

@@ -37,11 +37,7 @@ class ObjectIdTest {
   }
 
   @Test
-  fun testNullOrEmptyObjectId() {
-    val exception = assertThrows(AblyException::class.java) {
-      ObjectId.fromString(null)
-    }
-    assertAblyExceptionError(exception)
+  fun testEmptyObjectId() {
     val exception1 = assertThrows(AblyException::class.java) {
       ObjectId.fromString("")
     }