Allow tests to accedss CarouselItems post filter operation

osu.Game.Tests/Visual/SongSelectV2/BeatmapCarouselTestScene.cs

@@ -4,9 +4,11 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions;
 using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -35,7 +37,7 @@ namespace osu.Game.Tests.Visual.SongSelectV2
     {
         protected readonly BindableList<BeatmapSetInfo> BeatmapSets = new BindableList<BeatmapSetInfo>();
 
-        protected BeatmapCarousel Carousel = null!;
+        protected TestBeatmapCarousel Carousel = null!;
 
         protected OsuScrollContainer<Drawable> Scroll => Carousel.ChildrenOfType<OsuScrollContainer<Drawable>>().Single();
 
@@ -100,7 +102,7 @@ namespace osu.Game.Tests.Visual.SongSelectV2
                             },
                             new Drawable[]
                             {
-                                Carousel = new BeatmapCarousel
+                                Carousel = new TestBeatmapCarousel
                                 {
                                     NewItemsPresented = () => NewItemsPresentedInvocationCount++,
                                     BleedTop = 50,
@@ -351,5 +353,21 @@ namespace osu.Game.Tests.Visual.SongSelectV2
                 });
             }
         }
+
+        public class TestBeatmapCarousel : BeatmapCarousel
+        {
+            public IEnumerable<BeatmapInfo> PostFilterBeatmaps = null!;
+
+            protected override Task<IEnumerable<CarouselItem>> FilterAsync()
+            {
+                var filterAsync = base.FilterAsync();
+                filterAsync.ContinueWith(result =>
+                {
+                    if (result.IsCompletedSuccessfully)
+                        PostFilterBeatmaps = result.GetResultSafely().Select(i => i.Model).OfType<BeatmapInfo>();
+                });
+                return filterAsync;
+            }
+        }
     }
 }

osu.Game/Graphics/Carousel/Carousel.cs

@@ -170,7 +170,7 @@ namespace osu.Game.Graphics.Carousel
         /// <summary>
         /// Queue an asynchronous filter operation.
         /// </summary>
-        protected Task FilterAsync()
+        protected virtual Task<IEnumerable<CarouselItem>> FilterAsync()
         {
             filterTask = performFilter();
             filterTask.FireAndForget();
@@ -257,10 +257,10 @@ namespace osu.Game.Graphics.Carousel
 
         private List<CarouselItem>? carouselItems;
 
-        private Task filterTask = Task.CompletedTask;
+        private Task<IEnumerable<CarouselItem>> filterTask = Task.FromResult(Enumerable.Empty<CarouselItem>());
         private CancellationTokenSource cancellationSource = new CancellationTokenSource();
 
-        private async Task performFilter()
+        private async Task<IEnumerable<CarouselItem>> performFilter()
         {
             Stopwatch stopwatch = Stopwatch.StartNew();
             var cts = new CancellationTokenSource();
@@ -303,7 +303,7 @@ namespace osu.Game.Graphics.Carousel
             }, cts.Token).ConfigureAwait(false);
 
             if (cts.Token.IsCancellationRequested)
-                return;
+                return Enumerable.Empty<CarouselItem>();
 
             Schedule(() =>
             {
@@ -319,6 +319,8 @@ namespace osu.Game.Graphics.Carousel
                 NewItemsPresented?.Invoke();
             });
 
+            return items;
+
             void log(string text) => Logger.Log($"Carousel[op {cts.GetHashCode().ToString()}] {stopwatch.ElapsedMilliseconds} ms: {text}");
         }