void Check(bool value,string message){if(!value)throw new Exception(message);}
var s=new Subject();var pending=new Dictionary<string,string>{{"existing-key","existing-data"}};
s.dataBuffer.AddLast(pending);var spare=s.swapData;
PlayFabClientAPI.LoggedIn=false;s.Flush();
Check(PlayFabClientAPI.Calls==0&&ReferenceEquals(pending,s.dataBuffer.First.Value)&&ReferenceEquals(spare,s.swapData),"unauthorized flush changed queue");
var token=s.tokenSource.Token;s.Destroy();
Check(token.IsCancellationRequested&&s.tokenSource==null&&PlayerPrefs.Saves==1,"destroy must cancel and save local cache");
Check(PlayFabClientAPI.Calls==0&&pending["existing-key"]=="existing-data","destroy discarded pending data or uploaded without auth");
PlayFabClientAPI.LoggedIn=true;s.Flush();
Check(PlayFabClientAPI.Calls==1&&PlayFabClientAPI.Last.Data["existing-key"]=="existing-data","authorized upload regressed");
Console.WriteLine("PASS real SyncData/OnDestroy: unauthenticated queue unchanged, local Save, cancellation and authorized upload");
public static class PlayerPrefs{public static int Saves;public static void Save()=>Saves++;}
public class UpdateUserDataRequest{public Dictionary<string,string> Data;public UserDataPermission Permission;}
public enum UserDataPermission{Public}
public static class PlayFabClientAPI{
 public static bool LoggedIn;public static int Calls;public static UpdateUserDataRequest Last;
 public static bool IsClientLoggedIn()=>LoggedIn;
 public static void UpdateUserData(UpdateUserDataRequest request,Action<object> ok,Action<object> fail){if(!LoggedIn)throw new Exception("not logged in");Calls++;Last=request;}
}