Fix "server-side" room playlist not updated

Remove unused using

osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerPlaylist.cs

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;

osu.Game/Online/Rooms/PlaylistItem.cs

@@ -85,6 +85,19 @@ namespace osu.Game.Online.Rooms
             Beatmap = beatmap;
         }
 
+        public PlaylistItem(MultiplayerPlaylistItem item)
+            : this(new APIBeatmap { OnlineID = item.BeatmapID })
+        {
+            ID = item.ID;
+            OwnerID = item.OwnerID;
+            RulesetID = item.RulesetID;
+            Expired = item.Expired;
+            PlaylistOrder = item.PlaylistOrder;
+            PlayedAt = item.PlayedAt;
+            RequiredMods = item.RequiredMods.ToArray();
+            AllowedMods = item.AllowedMods.ToArray();
+        }
+
         public void MarkInvalid() => valid.Value = false;
 
         #region Newtonsoft.Json implicit ShouldSerialize() methods

osu.Game/Tests/Visual/Multiplayer/TestMultiplayerClient.cs

@@ -31,7 +31,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public override IBindable<bool> IsConnected => isConnected;
         private readonly Bindable<bool> isConnected = new Bindable<bool>(true);
 
+        /// <summary>
+        /// The local client's <see cref="Room"/>. This is not always equivalent to the server-side room.
+        /// </summary>
         public new Room? APIRoom => base.APIRoom;
+
         public Action<MultiplayerRoom>? RoomSetupAction;
 
         public bool RoomJoined { get; private set; }
@@ -46,6 +50,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
         /// </summary>
         private readonly List<MultiplayerPlaylistItem> serverSidePlaylist = new List<MultiplayerPlaylistItem>();
 
+        /// <summary>
+        /// Guaranteed up-to-date API room.
+        /// </summary>
+        private Room? serverSideAPIRoom;
+
         private MultiplayerPlaylistItem? currentItem => Room?.Playlist[currentIndex];
         private int currentIndex;
         private long lastPlaylistItemId;
@@ -192,13 +201,13 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         protected override async Task<MultiplayerRoom> JoinRoom(long roomId, string? password = null)
         {
-            var apiRoom = roomManager.ServerSideRooms.Single(r => r.RoomID.Value == roomId);
+            serverSideAPIRoom = roomManager.ServerSideRooms.Single(r => r.RoomID.Value == roomId);
 
-            if (password != apiRoom.Password.Value)
+            if (password != serverSideAPIRoom.Password.Value)
                 throw new InvalidOperationException("Invalid password.");
 
             serverSidePlaylist.Clear();
-            serverSidePlaylist.AddRange(apiRoom.Playlist.Select(item => new MultiplayerPlaylistItem(item)));
+            serverSidePlaylist.AddRange(serverSideAPIRoom.Playlist.Select(item => new MultiplayerPlaylistItem(item)));
             lastPlaylistItemId = serverSidePlaylist.Max(item => item.ID);
 
             var localUser = new MultiplayerRoomUser(api.LocalUser.Value.Id)
@@ -210,11 +219,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 Settings =
                 {
-                    Name = apiRoom.Name.Value,
+                    Name = serverSideAPIRoom.Name.Value,
-                    MatchType = apiRoom.Type.Value,
+                    MatchType = serverSideAPIRoom.Type.Value,
                     Password = password,
-                    QueueMode = apiRoom.QueueMode.Value,
+                    QueueMode = serverSideAPIRoom.QueueMode.Value,
-                    AutoStartDuration = apiRoom.AutoStartDuration.Value
+                    AutoStartDuration = serverSideAPIRoom.AutoStartDuration.Value
                 },
                 Playlist = serverSidePlaylist.ToList(),
                 Users = { localUser },
@@ -479,6 +488,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             Debug.Assert(Room != null);
             Debug.Assert(APIRoom != null);
+            Debug.Assert(serverSideAPIRoom != null);
 
             var item = serverSidePlaylist.Find(i => i.ID == playlistItemId);
 
@@ -495,6 +505,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 throw new InvalidOperationException("Attempted to remove an item which has already been played.");
 
             serverSidePlaylist.Remove(item);
+            serverSideAPIRoom.Playlist.RemoveAll(i => i.ID == item.ID);
             await ((IMultiplayerClient)this).PlaylistItemRemoved(playlistItemId).ConfigureAwait(false);
 
             await updateCurrentItem(Room).ConfigureAwait(false);
@@ -576,10 +587,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private async Task addItem(MultiplayerPlaylistItem item)
         {
             Debug.Assert(Room != null);
+            Debug.Assert(serverSideAPIRoom != null);
 
             item.ID = ++lastPlaylistItemId;
 
             serverSidePlaylist.Add(item);
+            serverSideAPIRoom.Playlist.Add(new PlaylistItem(item));
             await ((IMultiplayerClient)this).PlaylistItemAdded(item).ConfigureAwait(false);
 
             await updatePlaylistOrder(Room).ConfigureAwait(false);
@@ -603,6 +616,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         private async Task updatePlaylistOrder(MultiplayerRoom room)
         {
+            Debug.Assert(serverSideAPIRoom != null);
+
             List<MultiplayerPlaylistItem> orderedActiveItems;
 
             switch (room.Settings.QueueMode)
@@ -648,6 +663,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
                 await ((IMultiplayerClient)this).PlaylistItemChanged(item).ConfigureAwait(false);
             }
+
+            // Also ensure that the API room's playlist is correct.
+            foreach (var item in serverSideAPIRoom.Playlist)
+                item.PlaylistOrder = serverSidePlaylist.Single(i => i.ID == item.ID).PlaylistOrder;
         }
     }
 }