Merge branch 'ppy:master' into taiko-mod-simplified-rhythm

.github/workflows/ci.yml

@@ -114,7 +114,7 @@ jobs:
           dotnet-version: "8.0.x"
 
       - name: Install .NET workloads
-        run: dotnet workload install maui-android
+        run: dotnet workload install android
 
       - name: Compile
         run: dotnet build -c Debug osu.Android.slnf

osu.Android.props

@@ -10,7 +10,7 @@
     <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2024.1115.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2024.1118.0" />
   </ItemGroup>
   <PropertyGroup>
     <!-- Fody does not handle Android build well, and warns when unchanged.

osu.Game.Rulesets.Catch.Tests/Mods/TestSceneCatchModNoScope.cs

@@ -29,7 +29,7 @@ namespace osu.Game.Rulesets.Catch.Tests.Mods
                 },
                 Autoplay = true,
                 PassCondition = () => Player.ScoreProcessor.Combo.Value == 2,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {
@@ -59,7 +59,7 @@ namespace osu.Game.Rulesets.Catch.Tests.Mods
                 },
                 Autoplay = true,
                 PassCondition = () => true,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {
@@ -99,7 +99,7 @@ namespace osu.Game.Rulesets.Catch.Tests.Mods
                 },
                 Autoplay = true,
                 PassCondition = () => true,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {

osu.Game.Rulesets.Catch.Tests/Mods/TestSceneCatchModRelax.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Catch.Tests.Mods
             Mod = new CatchModRelax(),
             Autoplay = false,
             PassCondition = passCondition,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {

osu.Game.Rulesets.Catch.Tests/TestSceneCatchModHidden.cs

@@ -24,7 +24,7 @@ namespace osu.Game.Rulesets.Catch.Tests
         {
             CreateModTest(new ModTestData
             {
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {

osu.Game.Rulesets.Catch/Edit/CatchDistanceSnapProvider.cs

@@ -10,7 +10,7 @@ namespace osu.Game.Rulesets.Catch.Edit
 {
     public partial class CatchDistanceSnapProvider : ComposerDistanceSnapProvider
     {
-        protected override double ReadCurrentDistanceSnap(HitObject before, HitObject after)
+        public override double ReadCurrentDistanceSnap(HitObject before, HitObject after)
         {
             // osu!catch's distance snap implementation is limited, in that a custom spacing cannot be specified.
             // Therefore this functionality is not currently used.

osu.Game.Rulesets.Catch/Edit/CatchHitObjectComposer.cs

@@ -70,6 +70,8 @@ namespace osu.Game.Rulesets.Catch.Edit
             }));
         }
 
+        protected override Drawable CreateHitObjectInspector() => new CatchHitObjectInspector(DistanceSnapProvider);
+
         protected override IEnumerable<TernaryButton> CreateTernaryButtons()
             => base.CreateTernaryButtons()
                    .Concat(DistanceSnapProvider.CreateTernaryButtons());

osu.Game.Rulesets.Catch/Edit/CatchHitObjectInspector.cs

@@ -0,0 +1,41 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Linq;
+using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Screens.Edit.Compose.Components;
+
+namespace osu.Game.Rulesets.Catch.Edit
+{
+    public partial class CatchHitObjectInspector(CatchDistanceSnapProvider snapProvider) : HitObjectInspector
+    {
+        protected override void AddInspectorValues(HitObject[] objects)
+        {
+            base.AddInspectorValues(objects);
+
+            if (objects.Length > 0)
+            {
+                HitObject firstSelectedHitObject = objects.MinBy(ho => ho.StartTime)!;
+                HitObject lastSelectedHitObject = objects.MaxBy(ho => ho.GetEndTime())!;
+
+                HitObject? precedingObject = EditorBeatmap.HitObjects.LastOrDefault(ho => ho.GetEndTime() < firstSelectedHitObject.StartTime);
+                HitObject? nextObject = EditorBeatmap.HitObjects.FirstOrDefault(ho => ho.StartTime > lastSelectedHitObject.GetEndTime());
+
+                if (precedingObject != null && precedingObject is not BananaShower)
+                {
+                    double previousSnap = snapProvider.ReadCurrentDistanceSnap(precedingObject, firstSelectedHitObject);
+                    AddHeader("To previous");
+                    AddValue($"{previousSnap:#,0.##}x");
+                }
+
+                if (nextObject != null && nextObject is not BananaShower)
+                {
+                    double nextSnap = snapProvider.ReadCurrentDistanceSnap(lastSelectedHitObject, nextObject);
+                    AddHeader("To next");
+                    AddValue($"{nextSnap:#,0.##}x");
+                }
+            }
+        }
+    }
+}

osu.Game.Rulesets.Mania.Tests/ManiaScoreProcessorTest.cs

@@ -0,0 +1,39 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Collections.Generic;
+using NUnit.Framework;
+using osu.Game.Rulesets.Mania.Scoring;
+using osu.Game.Rulesets.Scoring;
+using osu.Game.Scoring;
+
+namespace osu.Game.Rulesets.Mania.Tests
+{
+    [TestFixture]
+    public class ManiaScoreProcessorTest
+    {
+        [TestCase(ScoreRank.X, 1, HitResult.Perfect)]
+        [TestCase(ScoreRank.X, 0.99, HitResult.Great)]
+        [TestCase(ScoreRank.D, 0.1, HitResult.Great)]
+        [TestCase(ScoreRank.X, 0.99, HitResult.Perfect, HitResult.Great)]
+        [TestCase(ScoreRank.X, 0.99, HitResult.Great, HitResult.Great)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Perfect, HitResult.Good)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Perfect, HitResult.Ok)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Perfect, HitResult.Meh)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Perfect, HitResult.Miss)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Great, HitResult.Good)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Great, HitResult.Ok)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Great, HitResult.Meh)]
+        [TestCase(ScoreRank.S, 0.99, HitResult.Great, HitResult.Miss)]
+        public void TestRanks(ScoreRank expected, double accuracy, params HitResult[] results)
+        {
+            var scoreProcessor = new ManiaScoreProcessor();
+
+            Dictionary<HitResult, int> resultsDict = new Dictionary<HitResult, int>();
+            foreach (var result in results)
+                resultsDict[result] = resultsDict.GetValueOrDefault(result) + 1;
+
+            Assert.That(scoreProcessor.RankFromScore(accuracy, resultsDict), Is.EqualTo(expected));
+        }
+    }
+}

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModAutoplay.cs

@@ -19,7 +19,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
             CreateModTest(new ModTestData
             {
                 Autoplay = true,
-                Beatmap = new ManiaBeatmap(new StageDefinition(1))
+                CreateBeatmap = () => new ManiaBeatmap(new StageDefinition(1))
                 {
                     HitObjects = new List<ManiaHitObject>
                     {

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModDoubleTime.cs

@@ -29,7 +29,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
                                   && Precision.AlmostEquals(Player.ScoreProcessor.Accuracy.Value, 0.9836, 0.01)
                                   && Player.ScoreProcessor.TotalScore.Value == 946_049,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 BeatmapInfo = { Ruleset = new ManiaRuleset().RulesetInfo },
                 Difficulty = { OverallDifficulty = 10 },
@@ -56,7 +56,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
                                       && Player.ScoreProcessor.Accuracy.Value == 1
                                       && Player.ScoreProcessor.TotalScore.Value == (long)(1_000_000 * doubleTime.ScoreMultiplier),
                 Autoplay = false,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     BeatmapInfo = { Ruleset = new ManiaRuleset().RulesetInfo },
                     Difficulty = { OverallDifficulty = 10 },

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModFadeIn.cs

@@ -74,7 +74,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
             CreateModTest(new ModTestData
             {
                 Mod = new ManiaModHidden(),
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = Enumerable.Range(1, 100).Select(i => (HitObject)new Note { StartTime = 1000 + 200 * i }).ToList(),
                     Breaks = { new BreakPeriod(2000, 28000) }

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModHidden.cs

@@ -74,7 +74,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
             CreateModTest(new ModTestData
             {
                 Mod = new ManiaModHidden(),
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = Enumerable.Range(1, 100).Select(i => (HitObject)new Note { StartTime = 1000 + 200 * i }).ToList(),
                     Breaks = { new BreakPeriod(2000, 28000) }

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModPerfect.cs

@@ -36,7 +36,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
             Mod = new ManiaModPerfect(),
             PassCondition = () => ((ModFailConditionTestPlayer)Player).CheckFailed(false),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -59,7 +59,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
             Mod = new ManiaModPerfect(),
             PassCondition = () => ((ModFailConditionTestPlayer)Player).CheckFailed(true) && Player.Results.Count == 2,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {

osu.Game.Rulesets.Mania.Tests/Mods/TestSceneManiaModSuddenDeath.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
             Mod = new ManiaModSuddenDeath(),
             PassCondition = () => ((ModFailConditionTestPlayer)Player).CheckFailed(false),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -51,7 +51,7 @@ namespace osu.Game.Rulesets.Mania.Tests.Mods
             Mod = new ManiaModSuddenDeath(),
             PassCondition = () => ((ModFailConditionTestPlayer)Player).CheckFailed(true) && Player.Results.Count == 2,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {

osu.Game.Rulesets.Mania/Edit/EditorColumn.cs

@@ -0,0 +1,45 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Graphics;
+using osu.Game.Rulesets.Mania.Objects.Drawables;
+using osu.Game.Rulesets.Mania.UI;
+using osu.Game.Rulesets.Objects.Drawables;
+
+namespace osu.Game.Rulesets.Mania.Edit
+{
+    public partial class EditorColumn : Column
+    {
+        public EditorColumn(int index, bool isSpecial)
+            : base(index, isSpecial)
+        {
+        }
+
+        protected override void OnNewDrawableHitObject(DrawableHitObject drawableHitObject)
+        {
+            base.OnNewDrawableHitObject(drawableHitObject);
+            drawableHitObject.ApplyCustomUpdateState += (dho, state) =>
+            {
+                switch (dho)
+                {
+                    // hold note heads are exempt from what follows due to the "freezing" mechanic
+                    // which already ensures they'll never fade away on their own.
+                    case DrawableHoldNoteHead:
+                        break;
+
+                    // mania features instantaneous hitobject fade-outs.
+                    // this means that without manual intervention stopping the clock at the precise time of hitting the object
+                    // means the object will fade out.
+                    // this is anti-user in editor contexts, as the user is expecting to continue the see the note on the receptor line.
+                    // therefore, apply a crude workaround to prevent it from going away.
+                    default:
+                    {
+                        if (state == ArmedState.Hit)
+                            dho.FadeTo(1).Delay(1).FadeOut().Expire();
+                        break;
+                    }
+                }
+            };
+        }
+    }
+}

osu.Game.Rulesets.Mania/Edit/EditorStage.cs

@@ -0,0 +1,18 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Rulesets.Mania.Beatmaps;
+using osu.Game.Rulesets.Mania.UI;
+
+namespace osu.Game.Rulesets.Mania.Edit
+{
+    public partial class EditorStage : Stage
+    {
+        public EditorStage(int firstColumnIndex, StageDefinition definition, ref ManiaAction columnStartAction)
+            : base(firstColumnIndex, definition, ref columnStartAction)
+        {
+        }
+
+        protected override Column CreateColumn(int index, bool isSpecial) => new EditorColumn(index, isSpecial);
+    }
+}

osu.Game.Rulesets.Mania/Edit/ManiaEditorPlayfield.cs

@@ -13,5 +13,8 @@ namespace osu.Game.Rulesets.Mania.Edit
             : base(stages)
         {
         }
+
+        protected override Stage CreateStage(int firstColumnIndex, StageDefinition stageDefinition, ref ManiaAction columnAction)
+            => new EditorStage(firstColumnIndex, stageDefinition, ref columnAction);
     }
 }

osu.Game.Rulesets.Mania/Scoring/ManiaScoreProcessor.cs

@@ -9,6 +9,7 @@ using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Scoring;
+using osu.Game.Scoring;
 
 namespace osu.Game.Rulesets.Mania.Scoring
 {
@@ -58,6 +59,24 @@ namespace osu.Game.Rulesets.Mania.Scoring
             return GetBaseScoreForResult(result);
         }
 
+        public override ScoreRank RankFromScore(double accuracy, IReadOnlyDictionary<HitResult, int> results)
+        {
+            ScoreRank rank = base.RankFromScore(accuracy, results);
+
+            if (rank != ScoreRank.S)
+                return rank;
+
+            // SS is expected as long as all hitobjects have been hit with either a GREAT or PERFECT result.
+
+            bool anyImperfect =
+                results.GetValueOrDefault(HitResult.Good) > 0
+                || results.GetValueOrDefault(HitResult.Ok) > 0
+                || results.GetValueOrDefault(HitResult.Meh) > 0
+                || results.GetValueOrDefault(HitResult.Miss) > 0;
+
+            return anyImperfect ? rank : ScoreRank.X;
+        }
+
         private class JudgementOrderComparer : IComparer<HitObject>
         {
             public static readonly JudgementOrderComparer DEFAULT = new JudgementOrderComparer();

osu.Game.Rulesets.Mania/UI/ManiaPlayfield.cs

@@ -7,6 +7,7 @@ using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using System;
 using System.Collections.Generic;
+using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics.Primitives;
 using osu.Game.Rulesets.Mania.Beatmaps;
@@ -71,7 +72,7 @@ namespace osu.Game.Rulesets.Mania.UI
 
             for (int i = 0; i < stageDefinitions.Count; i++)
             {
-                var newStage = new Stage(firstColumnIndex, stageDefinitions[i], ref columnAction);
+                var newStage = CreateStage(firstColumnIndex, stageDefinitions[i], ref columnAction);
 
                 playfieldGrid.Content[0][i] = newStage;
 
@@ -82,6 +83,9 @@ namespace osu.Game.Rulesets.Mania.UI
             }
         }
 
+        [Pure]
+        protected virtual Stage CreateStage(int firstColumnIndex, StageDefinition stageDefinition, ref ManiaAction columnAction) => new Stage(firstColumnIndex, stageDefinition, ref columnAction);
+
         public override void Add(HitObject hitObject) => getStageByColumn(((ManiaHitObject)hitObject).Column).Add(hitObject);
 
         public override bool Remove(HitObject hitObject) => getStageByColumn(((ManiaHitObject)hitObject).Column).Remove(hitObject);

osu.Game.Rulesets.Mania/UI/Stage.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Linq;
+using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
@@ -134,12 +135,14 @@ namespace osu.Game.Rulesets.Mania.UI
             {
                 bool isSpecial = definition.IsSpecialColumn(i);
 
-                var column = new Column(firstColumnIndex + i, isSpecial)
+                var action = columnStartAction;
+                columnStartAction++;
+                var column = CreateColumn(firstColumnIndex + i, isSpecial).With(c =>
                 {
-                    RelativeSizeAxes = Axes.Both,
-                    Width = 1,
-                    Action = { Value = columnStartAction++ }
-                };
+                    c.RelativeSizeAxes = Axes.Both;
+                    c.Width = 1;
+                    c.Action.Value = action;
+                });
 
                 topLevelContainer.Add(column.TopLevelContainer.CreateProxy());
                 columnBackgrounds.Add(column.BackgroundContainer.CreateProxy());
@@ -154,6 +157,9 @@ namespace osu.Game.Rulesets.Mania.UI
             RegisterPool<BarLine, DrawableBarLine>(50, 200);
         }
 
+        [Pure]
+        protected virtual Column CreateColumn(int index, bool isSpecial) => new Column(index, isSpecial);
+
         [BackgroundDependencyLoader]
         private void load(ISkinSource skin)
         {

osu.Game.Rulesets.Osu.Tests.iOS/osu.Game.Rulesets.Osu.Tests.iOS.csproj

@@ -17,4 +17,8 @@
     <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
     <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj" />
   </ItemGroup>
+  <ItemGroup Label="Package References">
+    <PackageReference Include="DeepEqual" Version="2.0.0" />
+    <PackageReference Include="Moq" Version="4.17.2" />
+  </ItemGroup>
 </Project>

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModAlternate.cs

@@ -23,7 +23,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModAlternate(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 4,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -68,7 +68,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModAlternate(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 0 && Player.ScoreProcessor.HighestCombo.Value == 1,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -101,7 +101,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModAlternate(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 1,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -131,7 +131,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModAlternate(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 0 && Player.ScoreProcessor.HighestCombo.Value == 2,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 Breaks =
                 {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModAutoplay.cs

@@ -60,7 +60,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             CreateModTest(new ModTestData
             {
                 Autoplay = true,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {
@@ -90,7 +90,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             {
                 Autoplay = true,
                 Mod = mod,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects =
                     {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModDifficultyAdjust.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
         public void TestNoAdjustment() => CreateModTest(new ModTestData
         {
             Mod = new OsuModDifficultyAdjust(),
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 BeatmapInfo = new BeatmapInfo
                 {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModFlashlight.cs

@@ -68,7 +68,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
                         Player.GameplayClockContainer.CurrentTime < 1000 && Player.ChildrenOfType<ModFlashlight<OsuHitObject>.Flashlight>().Single().FlashlightDim > 0;
                     return Player.GameplayState.HasPassed && !sliderDimmedBeforeStartTime;
                 },
-                Beatmap = new OsuBeatmap
+                CreateBeatmap = () => new OsuBeatmap
                 {
                     HitObjects = new List<OsuHitObject>
                     {
@@ -114,7 +114,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
                         Player.GameplayClockContainer.CurrentTime >= 1000 && Player.ChildrenOfType<ModFlashlight<OsuHitObject>.Flashlight>().Single().FlashlightDim > 0;
                     return Player.GameplayState.HasPassed && sliderDimmed;
                 },
-                Beatmap = new OsuBeatmap
+                CreateBeatmap = () => new OsuBeatmap
                 {
                     HitObjects = new List<OsuHitObject>
                     {
@@ -153,7 +153,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
                         Player.GameplayClockContainer.CurrentTime >= 1000 && Player.ChildrenOfType<ModFlashlight<OsuHitObject>.Flashlight>().Single().FlashlightDim > 0;
                     return Player.GameplayState.HasPassed && sliderDimmed;
                 },
-                Beatmap = new OsuBeatmap
+                CreateBeatmap = () => new OsuBeatmap
                 {
                     HitObjects = new List<OsuHitObject>
                     {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModHidden.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
         {
             Mod = new TestOsuModHidden(),
             Autoplay = true,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -63,7 +63,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
         {
             Mod = new TestOsuModHidden(),
             Autoplay = true,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -98,7 +98,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
         {
             Mod = new TestOsuModHidden(),
             Autoplay = true,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -122,7 +122,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
         {
             Mod = new OsuModHidden { OnlyFadeApproachCircles = { Value = true } },
             Autoplay = true,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModMirror.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
         public void TestCorrectReflections([Values] OsuModMirror.MirrorType type, [Values] bool withStrictTracking) => CreateModTest(new ModTestData
         {
             Autoplay = true,
-            Beatmap = new OsuBeatmap
+            CreateBeatmap = () => new OsuBeatmap
             {
                 HitObjects =
                 {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModNoScope.cs

@@ -31,7 +31,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
                 },
                 Autoplay = true,
                 PassCondition = () => true,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {
@@ -71,7 +71,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
                 },
                 Autoplay = true,
                 PassCondition = () => true,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {
@@ -113,7 +113,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
                 },
                 Autoplay = true,
                 PassCondition = () => true,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = new List<HitObject>
                     {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModPerfect.cs

@@ -61,7 +61,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModPerfect(),
             PassCondition = () => ((ModFailConditionTestPlayer)Player).CheckFailed(true),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModRandom.cs

@@ -36,7 +36,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             {
                 AngleSharpness = { Value = angleSharpness }
             },
-            Beatmap = jumpBeatmap,
+            CreateBeatmap = jumpBeatmap,
             Autoplay = true,
             PassCondition = () => true
         });
@@ -50,15 +50,15 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             {
                 AngleSharpness = { Value = angleSharpness }
             },
-            Beatmap = streamBeatmap,
+            CreateBeatmap = streamBeatmap,
             Autoplay = true,
             PassCondition = () => true
         });
 
-        private OsuBeatmap jumpBeatmap =>
+        private OsuBeatmap jumpBeatmap() =>
             createHitCircleBeatmap(new[] { 100, 200, 300, 400 }, 8, 300, 2 * 300);
 
-        private OsuBeatmap streamBeatmap =>
+        private OsuBeatmap streamBeatmap() =>
             createHitCircleBeatmap(new[] { 10, 20, 30, 40, 50, 60, 70, 80 }, 16, 150, 4 * 150);
 
         private OsuBeatmap createHitCircleBeatmap(IEnumerable<int> spacings, int objectsPerSpacing, int interval, int beatLength)

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModSingleTap.cs

@@ -22,7 +22,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModSingleTap(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 2,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -62,7 +62,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModSingleTap(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 0 && Player.ScoreProcessor.HighestCombo.Value == 1,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -100,7 +100,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModSingleTap(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 1,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -130,7 +130,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModSingleTap(),
             PassCondition = () => Player.ScoreProcessor.Combo.Value == 0 && Player.ScoreProcessor.HighestCombo.Value == 2,
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 Breaks =
                 {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModSpunOut.cs

@@ -35,7 +35,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             {
                 Mod = new OsuModSpunOut(),
                 Autoplay = false,
-                Beatmap = singleSpinnerBeatmap,
+                CreateBeatmap = singleSpinnerBeatmap,
                 PassCondition = () =>
                 {
                     // Bind to the first spinner's results for further tracking.
@@ -71,7 +71,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             {
                 Mods = mods,
                 Autoplay = false,
-                Beatmap = singleSpinnerBeatmap,
+                CreateBeatmap = singleSpinnerBeatmap,
                 PassCondition = () =>
                 {
                     var counter = Player.ChildrenOfType<SpinnerSpmCalculator>().SingleOrDefault();
@@ -101,7 +101,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             {
                 Mod = new OsuModSpunOut(),
                 Autoplay = false,
-                Beatmap = singleSpinnerBeatmap,
+                CreateBeatmap = singleSpinnerBeatmap,
                 PassCondition = () =>
                 {
                     // Bind to the first spinner's results for further tracking.
@@ -130,7 +130,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             });
         }
 
-        private Beatmap singleSpinnerBeatmap => new Beatmap
+        private Beatmap singleSpinnerBeatmap() => new Beatmap
         {
             HitObjects = new List<HitObject>
             {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModStrictTracking.cs

@@ -20,7 +20,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
         {
             Mod = new OsuModStrictTracking(),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModSuddenDeath.cs

@@ -30,7 +30,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModSuddenDeath(),
             PassCondition = () => ((ModFailConditionTestPlayer)Player).CheckFailed(false),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -55,7 +55,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             Mod = new OsuModSuddenDeath(),
             PassCondition = () => ((ModFailConditionTestPlayer)Player).CheckFailed(true),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {

osu.Game.Rulesets.Osu.Tests/TestSceneMissHitWindowJudgements.cs

@@ -36,7 +36,7 @@ namespace osu.Game.Rulesets.Osu.Tests
             {
                 Autoplay = false,
                 Mod = new TestAutoMod(),
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = { new HitCircle { Position = new Vector2(256, 192) } }
                 },
@@ -47,18 +47,16 @@ namespace osu.Game.Rulesets.Osu.Tests
         [Test]
         public void TestMissViaNotHitting()
         {
-            var beatmap = new Beatmap
-            {
-                HitObjects = { new HitCircle { Position = new Vector2(256, 192) } }
-            };
-
             var hitWindows = new OsuHitWindows();
-            hitWindows.SetDifficulty(beatmap.Difficulty.OverallDifficulty);
+            hitWindows.SetDifficulty(IBeatmapDifficultyInfo.DEFAULT_DIFFICULTY);
 
             CreateModTest(new ModTestData
             {
                 Autoplay = false,
-                Beatmap = beatmap,
+                CreateBeatmap = () => new Beatmap
+                {
+                    HitObjects = { new HitCircle { Position = new Vector2(256, 192) } }
+                },
                 PassCondition = () => Player.Results.Count > 0 && Player.Results[0].TimeOffset >= hitWindows.WindowFor(HitResult.Meh) && !Player.Results[0].IsHit
             });
         }

osu.Game.Rulesets.Osu/Edit/OsuDistanceSnapProvider.cs

@@ -12,7 +12,7 @@ namespace osu.Game.Rulesets.Osu.Edit
 {
     public partial class OsuDistanceSnapProvider : ComposerDistanceSnapProvider
     {
-        protected override double ReadCurrentDistanceSnap(HitObject before, HitObject after)
+        public override double ReadCurrentDistanceSnap(HitObject before, HitObject after)
         {
             float expectedDistance = DurationToDistance(before, after.StartTime - before.GetEndTime());
             float actualDistance = Vector2.Distance(((OsuHitObject)before).EndPosition, ((OsuHitObject)after).Position);

osu.Game.Rulesets.Taiko.Tests.iOS/osu.Game.Rulesets.Taiko.Tests.iOS.csproj

@@ -13,7 +13,8 @@
     </Compile>
   </ItemGroup>
   <ItemGroup Label="Project References">
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
     <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
+    <ProjectReference Include="..\osu.Game.Tests\osu.Game.Tests.csproj" />
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
 </Project>

osu.Game.Rulesets.Taiko.Tests/Mods/TestSceneTaikoModHidden.cs

@@ -31,40 +31,42 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
         {
             const double hit_time = 1;
 
-            var beatmap = new Beatmap<TaikoHitObject>
-            {
-                HitObjects = new List<TaikoHitObject>
-                {
-                    new Hit
-                    {
-                        Type = HitType.Rim,
-                        StartTime = hit_time,
-                    },
-                    new Hit
-                    {
-                        Type = HitType.Centre,
-                        StartTime = hit_time * 2,
-                    },
-                },
-                BeatmapInfo =
-                {
-                    Difficulty = new BeatmapDifficulty
-                    {
-                        SliderTickRate = 4,
-                        OverallDifficulty = 0,
-                    },
-                    Ruleset = new TaikoRuleset().RulesetInfo
-                },
-            };
-
-            beatmap.ControlPointInfo.Add(0, new EffectControlPoint { ScrollSpeed = 0.1f });
-
             CreateModTest(new ModTestData
             {
                 Mod = new TaikoModHidden(),
                 Autoplay = true,
                 PassCondition = checkAllMaxResultJudgements(2),
-                Beatmap = beatmap,
+                CreateBeatmap = () =>
+                {
+                    var beatmap = new Beatmap<TaikoHitObject>
+                    {
+                        HitObjects = new List<TaikoHitObject>
+                        {
+                            new Hit
+                            {
+                                Type = HitType.Rim,
+                                StartTime = hit_time,
+                            },
+                            new Hit
+                            {
+                                Type = HitType.Centre,
+                                StartTime = hit_time * 2,
+                            },
+                        },
+                        BeatmapInfo =
+                        {
+                            Difficulty = new BeatmapDifficulty
+                            {
+                                SliderTickRate = 4,
+                                OverallDifficulty = 0,
+                            },
+                            Ruleset = new TaikoRuleset().RulesetInfo
+                        },
+                    };
+
+                    beatmap.ControlPointInfo.Add(0, new EffectControlPoint { ScrollSpeed = 0.1f });
+                    return beatmap;
+                },
             });
         }
     }

osu.Game.Rulesets.Taiko.Tests/Mods/TestSceneTaikoModRelax.cs

@@ -15,7 +15,26 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
         [Test]
         public void TestRelax()
         {
-            var beatmap = new TaikoBeatmap
+            var beatmapForReplay = createBeatmap();
+
+            foreach (var ho in beatmapForReplay.HitObjects)
+                ho.ApplyDefaults(beatmapForReplay.ControlPointInfo, beatmapForReplay.Difficulty);
+
+            var replay = new TaikoAutoGenerator(beatmapForReplay).Generate();
+
+            foreach (var frame in replay.Frames.OfType<TaikoReplayFrame>().Where(r => r.Actions.Any()))
+                frame.Actions = [TaikoAction.LeftCentre];
+
+            CreateModTest(new ModTestData
+            {
+                Mod = new TaikoModRelax(),
+                CreateBeatmap = createBeatmap,
+                ReplayFrames = replay.Frames,
+                Autoplay = false,
+                PassCondition = () => Player.ScoreProcessor.HasCompleted.Value && Player.ScoreProcessor.Accuracy.Value == 1,
+            });
+
+            TaikoBeatmap createBeatmap() => new TaikoBeatmap
             {
                 HitObjects =
                 {
@@ -25,22 +44,6 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
                     new Swell { StartTime = 1250, Duration = 500 },
                 }
             };
-            foreach (var ho in beatmap.HitObjects)
-                ho.ApplyDefaults(beatmap.ControlPointInfo, beatmap.Difficulty);
-
-            var replay = new TaikoAutoGenerator(beatmap).Generate();
-
-            foreach (var frame in replay.Frames.OfType<TaikoReplayFrame>().Where(r => r.Actions.Any()))
-                frame.Actions = [TaikoAction.LeftCentre];
-
-            CreateModTest(new ModTestData
-            {
-                Mod = new TaikoModRelax(),
-                Beatmap = beatmap,
-                ReplayFrames = replay.Frames,
-                Autoplay = false,
-                PassCondition = () => Player.ScoreProcessor.HasCompleted.Value && Player.ScoreProcessor.Accuracy.Value == 1,
-            });
         }
     }
 }

osu.Game.Rulesets.Taiko.Tests/Mods/TestSceneTaikoModSingleTap.cs

@@ -20,7 +20,7 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
         {
             Mod = new TaikoModSingleTap(),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -65,7 +65,7 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
         {
             Mod = new TaikoModSingleTap(),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -110,7 +110,7 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
         {
             Mod = new TaikoModSingleTap(),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -136,7 +136,7 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
         {
             Mod = new TaikoModSingleTap(),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 HitObjects = new List<HitObject>
                 {
@@ -175,7 +175,7 @@ namespace osu.Game.Rulesets.Taiko.Tests.Mods
         {
             Mod = new TaikoModSingleTap(),
             Autoplay = false,
-            Beatmap = new Beatmap
+            CreateBeatmap = () => new Beatmap
             {
                 Breaks =
                 {

osu.Game.Tests/Beatmaps/IO/LegacyBeatmapExporterTest.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.IO;
+using System.Text;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions;
@@ -9,6 +10,7 @@ using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Testing;
 using osu.Game.Beatmaps;
 using osu.Game.Database;
+using osu.Game.IO.Archives;
 using osu.Game.Tests.Resources;
 using osu.Game.Tests.Visual;
 using MemoryStream = System.IO.MemoryStream;
@@ -48,6 +50,47 @@ namespace osu.Game.Tests.Beatmaps.IO
             AddAssert("hit object is snapped", () => beatmap.Beatmap.HitObjects[0].StartTime, () => Is.EqualTo(28519).Within(0.001));
         }
 
+        [Test]
+        public void TestExportStability()
+        {
+            IWorkingBeatmap beatmap = null!;
+            MemoryStream firstExport = null!;
+            MemoryStream secondExport = null!;
+
+            // Ensure importer encoding is correct
+            AddStep("import beatmap", () => beatmap = importBeatmapFromArchives(@"legacy-export-stability-test.olz"));
+            AddStep("export once", () =>
+            {
+                firstExport = new MemoryStream();
+
+                new LegacyBeatmapExporter(LocalStorage)
+                    .ExportToStream((BeatmapSetInfo)beatmap.BeatmapInfo.BeatmapSet!, firstExport, null);
+            });
+
+            AddStep("import beatmap again", () => beatmap = importBeatmapFromStream(firstExport));
+            AddStep("export again", () =>
+            {
+                secondExport = new MemoryStream();
+
+                new LegacyBeatmapExporter(LocalStorage)
+                    .ExportToStream((BeatmapSetInfo)beatmap.BeatmapInfo.BeatmapSet!, secondExport, null);
+            });
+
+            const string osu_filename = @"legacy export - stability test (spaceman_atlas) [].osu";
+
+            AddAssert("exports are identical",
+                () => getStringContentsOf(osu_filename, firstExport.GetBuffer()),
+                () => Is.EqualTo(getStringContentsOf(osu_filename, secondExport.GetBuffer())));
+
+            string getStringContentsOf(string filename, byte[] archiveBytes)
+            {
+                using var memoryStream = new MemoryStream(archiveBytes);
+                using var archiveReader = new ZipArchiveReader(memoryStream);
+                byte[] fileContent = archiveReader.GetStream(filename).ReadAllBytesToArray();
+                return Encoding.UTF8.GetString(fileContent);
+            }
+        }
+
         private IWorkingBeatmap importBeatmapFromStream(Stream stream)
         {
             var imported = beatmaps.Import(new ImportTask(stream, "filename.osz")).GetResultSafely();

osu.Game.Tests/NonVisual/Filtering/FilterMatchingTest.cs

@@ -148,6 +148,7 @@ namespace osu.Game.Tests.NonVisual.Filtering
         [TestCase("tags too", false)]
         [TestCase("version", false)]
         [TestCase("an auteur", true)]
+        [TestCase("unit", false)]
         public void TestCriteriaMatchingTerms(string terms, bool filtered)
         {
             var exampleBeatmapInfo = getExampleBeatmap();
@@ -175,6 +176,7 @@ namespace osu.Game.Tests.NonVisual.Filtering
         [TestCase("\"Artist\"!", true)]
         [TestCase("\"The Artist\"!", false)]
         [TestCase("\"the artist\"!", false)]
+        [TestCase("\"unit tests\"!", false)]
         [TestCase("\"\\\"", true)] // nasty case, covers properly escaping user input in underlying regex.
         public void TestCriteriaMatchingExactTerms(string terms, bool filtered)
         {

osu.Game.Tests/NonVisual/Filtering/FilterQueryParserTest.cs

@@ -501,6 +501,18 @@ namespace osu.Game.Tests.NonVisual.Filtering
             Assert.That(visibleBeatmaps, Is.EqualTo(expectedBeatmapIndexes));
         }
 
+        [Test]
+        public void TestApplySourceQueries()
+        {
+            const string query = "find me songs with source=\"unit tests\" please";
+            var filterCriteria = new FilterCriteria();
+            FilterQueryParser.ApplyQueries(filterCriteria, query);
+            Assert.AreEqual("find me songs with  please", filterCriteria.SearchText.Trim());
+            Assert.AreEqual(5, filterCriteria.SearchTerms.Length);
+            Assert.AreEqual("unit tests", filterCriteria.Source.SearchTerm);
+            Assert.That(filterCriteria.Source.MatchMode, Is.EqualTo(FilterCriteria.MatchMode.IsolatedPhrase));
+        }
+
         private class CustomFilterCriteria : IRulesetFilterCriteria
         {
             public string? CustomValue { get; set; }

osu.Game.Tests/NonVisual/Multiplayer/StatefulMultiplayerClientTest.cs

@@ -73,9 +73,9 @@ namespace osu.Game.Tests.NonVisual.Multiplayer
             AddStep("create room initially in gameplay", () =>
             {
                 var newRoom = new Room();
-                newRoom.CopyFrom(SelectedRoom.Value);
+                newRoom.CopyFrom(SelectedRoom.Value!);
 
-                newRoom.RoomID.Value = null;
+                newRoom.RoomID = null;
                 MultiplayerClient.RoomSetupAction = room =>
                 {
                     room.State = MultiplayerRoomState.Playing;

osu.Game.Tests/OnlinePlay/TestSceneCatchUpSyncManager.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using NUnit.Framework;
@@ -21,12 +19,12 @@ namespace osu.Game.Tests.OnlinePlay
     [HeadlessTest]
     public partial class TestSceneCatchUpSyncManager : OsuTestScene
     {
-        private GameplayClockContainer master;
-        private SpectatorSyncManager syncManager;
+        private GameplayClockContainer master = null!;
+        private SpectatorSyncManager syncManager = null!;
 
-        private Dictionary<SpectatorPlayerClock, int> clocksById;
-        private SpectatorPlayerClock player1;
-        private SpectatorPlayerClock player2;
+        private Dictionary<SpectatorPlayerClock, int> clocksById = null!;
+        private SpectatorPlayerClock player1 = null!;
+        private SpectatorPlayerClock player2 = null!;
 
         [SetUp]
         public void Setup()

osu.Game.Tests/Visual/Collections/TestSceneManageCollectionsDialog.cs

@@ -12,6 +12,7 @@ using osu.Framework.Platform;
 using osu.Framework.Testing;
 using osu.Game.Beatmaps;
 using osu.Game.Collections;
+using osu.Game.Graphics.UserInterface;
 using osu.Game.Overlays;
 using osu.Game.Overlays.Dialog;
 using osu.Game.Rulesets;
@@ -265,7 +266,6 @@ namespace osu.Game.Tests.Visual.Collections
         }
 
         [Test]
-        [Solo]
         public void TestCollectionRenamedExternal()
         {
             BeatmapCollection first = null!;
@@ -338,10 +338,44 @@ namespace osu.Game.Tests.Visual.Collections
             AddUntilStep("collection has new name", () => first.Name == "First");
         }
 
+        [Test]
+        public void TestSearch()
+        {
+            BeatmapCollection first = null!;
+
+            AddStep("add two collections", () =>
+            {
+                Realm.Write(r =>
+                {
+                    r.Add(new[]
+                    {
+                        first = new BeatmapCollection(name: "1"),
+                        new BeatmapCollection(name: "2"),
+                    });
+                });
+            });
+
+            assertCollectionName(0, "1");
+            assertCollectionName(1, "2");
+
+            AddStep("search for 1", () => dialog.ChildrenOfType<SearchTextBox>().Single().Current.Value = "1");
+
+            assertCollectionCount(1);
+
+            AddStep("change first collection name", () => Realm.Write(_ => first.Name = "First"));
+
+            assertCollectionCount(0);
+
+            AddStep("search for first", () => dialog.ChildrenOfType<SearchTextBox>().Single().Current.Value = "firs");
+
+            assertCollectionCount(1);
+        }
+
         private void assertCollectionCount(int count)
-            => AddUntilStep($"{count} collections shown", () => dialog.ChildrenOfType<DrawableCollectionListItem>().Count() == count + 1); // +1 for placeholder
+            => AddUntilStep($"{count} collections shown", () => dialog.ChildrenOfType<DrawableCollectionListItem>().Count(i => i.IsPresent) == count + 1); // +1 for placeholder
 
         private void assertCollectionName(int index, string name)
-            => AddUntilStep($"item {index + 1} has correct name", () => dialog.ChildrenOfType<DrawableCollectionList>().Single().OrderedItems.ElementAt(index).ChildrenOfType<TextBox>().First().Text == name);
+            => AddUntilStep($"item {index + 1} has correct name",
+                () => dialog.ChildrenOfType<DrawableCollectionList>().Single().OrderedItems.ElementAt(index).ChildrenOfType<TextBox>().First().Text == name);
     }
 }

osu.Game.Tests/Visual/DailyChallenge/TestSceneDailyChallenge.cs

@@ -39,18 +39,18 @@ namespace osu.Game.Tests.Visual.DailyChallenge
         {
             var room = new Room
             {
-                RoomID = { Value = 1234 },
-                Name = { Value = "Daily Challenge: June 4, 2024" },
+                RoomID = 1234,
+                Name = "Daily Challenge: June 4, 2024",
                 Playlist =
-                {
+                [
                     new PlaylistItem(TestResources.CreateTestBeatmapSetInfo().Beatmaps.First())
                     {
                         RequiredMods = [new APIMod(new OsuModTraceable())],
                         AllowedMods = [new APIMod(new OsuModDoubleTime())]
                     }
-                },
-                EndDate = { Value = DateTimeOffset.Now.AddHours(12) },
-                Category = { Value = RoomCategory.DailyChallenge }
+                ],
+                EndDate = DateTimeOffset.Now.AddHours(12),
+                Category = RoomCategory.DailyChallenge
             };
 
             AddStep("add room", () => API.Perform(new CreateRoomRequest(room)));
@@ -62,18 +62,18 @@ namespace osu.Game.Tests.Visual.DailyChallenge
         {
             var room = new Room
             {
-                RoomID = { Value = 1234 },
-                Name = { Value = "Daily Challenge: June 4, 2024" },
+                RoomID = 1234,
+                Name = "Daily Challenge: June 4, 2024",
                 Playlist =
-                {
+                [
                     new PlaylistItem(TestResources.CreateTestBeatmapSetInfo().Beatmaps.First())
                     {
                         RequiredMods = [new APIMod(new OsuModTraceable())],
                         AllowedMods = [new APIMod(new OsuModDoubleTime())]
                     }
-                },
-                EndDate = { Value = DateTimeOffset.Now.AddHours(12) },
-                Category = { Value = RoomCategory.DailyChallenge }
+                ],
+                EndDate = DateTimeOffset.Now.AddHours(12),
+                Category = RoomCategory.DailyChallenge
             };
 
             AddStep("add room", () => API.Perform(new CreateRoomRequest(room)));
@@ -91,18 +91,18 @@ namespace osu.Game.Tests.Visual.DailyChallenge
         {
             var room = new Room
             {
-                RoomID = { Value = 1234 },
-                Name = { Value = "Daily Challenge: June 4, 2024" },
+                RoomID = 1234,
+                Name = "Daily Challenge: June 4, 2024",
                 Playlist =
-                {
+                [
                     new PlaylistItem(TestResources.CreateTestBeatmapSetInfo().Beatmaps.First())
                     {
                         RequiredMods = [new APIMod(new OsuModTraceable())],
                         AllowedMods = [new APIMod(new OsuModDoubleTime())]
                     }
-                },
-                EndDate = { Value = DateTimeOffset.Now.AddHours(12) },
-                Category = { Value = RoomCategory.DailyChallenge }
+                ],
+                EndDate = DateTimeOffset.Now.AddHours(12),
+                Category = RoomCategory.DailyChallenge
             };
 
             AddStep("add room", () => API.Perform(new CreateRoomRequest(room)));

osu.Game.Tests/Visual/DailyChallenge/TestSceneDailyChallengeCarousel.cs

@@ -26,11 +26,6 @@ namespace osu.Game.Tests.Visual.DailyChallenge
 
         private readonly Bindable<Room> room = new Bindable<Room>(new Room());
 
-        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent) => new CachedModelDependencyContainer<Room>(base.CreateChildDependencies(parent))
-        {
-            Model = { BindTarget = room }
-        };
-
         [Test]
         public void TestBasicAppearance()
         {
@@ -98,7 +93,7 @@ namespace osu.Game.Tests.Visual.DailyChallenge
                                 Origin = Anchor.Centre,
                                 Children = new Drawable[]
                                 {
-                                    new DailyChallengeTimeRemainingRing(),
+                                    new DailyChallengeTimeRemainingRing(room.Value),
                                     breakdown = new DailyChallengeScoreBreakdown(),
                                 }
                             }
@@ -125,8 +120,8 @@ namespace osu.Game.Tests.Visual.DailyChallenge
             AddSliderStep("update time remaining", 0f, 1f, 0f, progress =>
             {
                 var startedTimeAgo = TimeSpan.FromHours(24) * progress;
-                room.Value.StartDate.Value = DateTimeOffset.Now - startedTimeAgo;
-                room.Value.EndDate.Value = room.Value.StartDate.Value.Value.AddDays(1);
+                room.Value.StartDate = DateTimeOffset.Now - startedTimeAgo;
+                room.Value.EndDate = room.Value.StartDate.Value.AddDays(1);
             });
             AddStep("add normal score", () =>
             {

osu.Game.Tests/Visual/DailyChallenge/TestSceneDailyChallengeIntro.cs

@@ -68,19 +68,19 @@ namespace osu.Game.Tests.Visual.DailyChallenge
             {
                 API.Perform(new CreateRoomRequest(room = new Room
                 {
-                    RoomID = { Value = roomId },
-                    Name = { Value = "Daily Challenge: June 4, 2024" },
+                    RoomID = roomId,
+                    Name = "Daily Challenge: June 4, 2024",
                     Playlist =
-                    {
+                    [
                         new PlaylistItem(CreateAPIBeatmap(new OsuRuleset().RulesetInfo))
                         {
                             RequiredMods = [new APIMod(new OsuModTraceable())],
                             AllowedMods = [new APIMod(new OsuModDoubleTime())]
                         }
-                    },
-                    StartDate = { Value = DateTimeOffset.Now },
-                    EndDate = { Value = DateTimeOffset.Now.AddHours(24) },
-                    Category = { Value = RoomCategory.DailyChallenge }
+                    ],
+                    StartDate = DateTimeOffset.Now,
+                    EndDate = DateTimeOffset.Now.AddHours(24),
+                    Category = RoomCategory.DailyChallenge
                 }));
             });
             AddStep("signal client", () => metadataClient.DailyChallengeUpdated(new DailyChallengeInfo { RoomID = roomId }));

osu.Game.Tests/Visual/DailyChallenge/TestSceneDailyChallengeLeaderboard.cs

@@ -43,7 +43,7 @@ namespace osu.Game.Tests.Visual.DailyChallenge
                     return false;
                 };
             });
-            AddStep("create leaderboard", () => Child = leaderboard = new DailyChallengeLeaderboard(new Room { RoomID = { Value = 1 } }, new PlaylistItem(Beatmap.Value.BeatmapInfo))
+            AddStep("create leaderboard", () => Child = leaderboard = new DailyChallengeLeaderboard(new Room { RoomID = 1 }, new PlaylistItem(Beatmap.Value.BeatmapInfo))
             {
                 RelativeSizeAxes = Axes.Both,
                 Anchor = Anchor.Centre,
@@ -86,7 +86,7 @@ namespace osu.Game.Tests.Visual.DailyChallenge
                     return false;
                 };
             });
-            AddStep("create leaderboard", () => Child = leaderboard = new DailyChallengeLeaderboard(new Room { RoomID = { Value = 1 } }, new PlaylistItem(Beatmap.Value.BeatmapInfo))
+            AddStep("create leaderboard", () => Child = leaderboard = new DailyChallengeLeaderboard(new Room { RoomID = 1 }, new PlaylistItem(Beatmap.Value.BeatmapInfo))
             {
                 RelativeSizeAxes = Axes.Both,
                 Anchor = Anchor.Centre,

osu.Game.Tests/Visual/DailyChallenge/TestSceneDailyChallengeTimeRemainingRing.cs

@@ -18,11 +18,6 @@ namespace osu.Game.Tests.Visual.DailyChallenge
     {
         private readonly Bindable<Room> room = new Bindable<Room>(new Room());
 
-        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent) => new CachedModelDependencyContainer<Room>(base.CreateChildDependencies(parent))
-        {
-            Model = { BindTarget = room }
-        };
-
         [Cached]
         private OverlayColourProvider colourProvider = new OverlayColourProvider(OverlayColourScheme.Plum);
 
@@ -38,7 +33,7 @@ namespace osu.Game.Tests.Visual.DailyChallenge
                     RelativeSizeAxes = Axes.Both,
                     Colour = colourProvider.Background4,
                 },
-                ring = new DailyChallengeTimeRemainingRing
+                ring = new DailyChallengeTimeRemainingRing(room.Value)
                 {
                     RelativeSizeAxes = Axes.Both,
                     Anchor = Anchor.Centre,
@@ -59,29 +54,29 @@ namespace osu.Game.Tests.Visual.DailyChallenge
 
             AddStep("just started", () =>
             {
-                room.Value.StartDate.Value = DateTimeOffset.Now.AddMinutes(-1);
-                room.Value.EndDate.Value = room.Value.StartDate.Value.Value.AddDays(1);
+                room.Value.StartDate = DateTimeOffset.Now.AddMinutes(-1);
+                room.Value.EndDate = room.Value.StartDate.Value.AddDays(1);
             });
             AddStep("midway through", () =>
             {
-                room.Value.StartDate.Value = DateTimeOffset.Now.AddHours(-12);
-                room.Value.EndDate.Value = room.Value.StartDate.Value.Value.AddDays(1);
+                room.Value.StartDate = DateTimeOffset.Now.AddHours(-12);
+                room.Value.EndDate = room.Value.StartDate.Value.AddDays(1);
             });
             AddStep("nearing end", () =>
             {
-                room.Value.StartDate.Value = DateTimeOffset.Now.AddDays(-1).AddMinutes(8);
-                room.Value.EndDate.Value = room.Value.StartDate.Value.Value.AddDays(1);
+                room.Value.StartDate = DateTimeOffset.Now.AddDays(-1).AddMinutes(8);
+                room.Value.EndDate = room.Value.StartDate.Value.AddDays(1);
             });
             AddStep("already ended", () =>
             {
-                room.Value.StartDate.Value = DateTimeOffset.Now.AddDays(-2);
-                room.Value.EndDate.Value = room.Value.StartDate.Value.Value.AddDays(1);
+                room.Value.StartDate = DateTimeOffset.Now.AddDays(-2);
+                room.Value.EndDate = room.Value.StartDate.Value.AddDays(1);
             });
             AddSliderStep("manual progress", 0f, 1f, 0f, progress =>
             {
                 var startedTimeAgo = TimeSpan.FromHours(24) * progress;
-                room.Value.StartDate.Value = DateTimeOffset.Now - startedTimeAgo;
-                room.Value.EndDate.Value = room.Value.StartDate.Value.Value.AddDays(1);
+                room.Value.StartDate = DateTimeOffset.Now - startedTimeAgo;
+                room.Value.EndDate = room.Value.StartDate.Value.AddDays(1);
             });
         }
     }

osu.Game.Tests/Visual/Gameplay/TestScenePlayerLoader.cs

@@ -18,6 +18,7 @@ using osu.Framework.Testing;
 using osu.Framework.Utils;
 using osu.Game.Beatmaps;
 using osu.Game.Configuration;
+using osu.Game.Graphics.UserInterface;
 using osu.Game.Overlays;
 using osu.Game.Overlays.Notifications;
 using osu.Game.Rulesets.Mods;
@@ -207,7 +208,25 @@ namespace osu.Game.Tests.Visual.Gameplay
         }
 
         [Test]
-        public void TestBlockLoadViaFocus()
+        public void TestLoadNotBlockedViaArbitraryFocus()
+        {
+            AddStep("load dummy beatmap", () => resetPlayer(false));
+            AddUntilStep("wait for current", () => loader.IsCurrentScreen());
+
+            AddUntilStep("click settings slider", () =>
+            {
+                InputManager.MoveMouseTo(loader.ChildrenOfType<OsuSliderBar<float>>().First());
+                InputManager.Click(MouseButton.Left);
+
+                return InputManager.FocusedDrawable is OsuSliderBar<float>;
+            });
+
+            AddUntilStep("wait for load ready", () => player?.LoadState == LoadState.Ready);
+            AddUntilStep("loads", () => !loader.IsCurrentScreen());
+        }
+
+        [Test]
+        public void TestBlockLoadViaOverlayFocus()
         {
             AddStep("load dummy beatmap", () => resetPlayer(false));
             AddUntilStep("wait for current", () => loader.IsCurrentScreen());

osu.Game.Tests/Visual/Menus/TestSceneMainMenu.cs

@@ -42,14 +42,14 @@ namespace osu.Game.Tests.Visual.Menus
                         beatmap.OnlineID = 1001;
                         getRoomRequest.TriggerSuccess(new Room
                         {
-                            RoomID = { Value = 1234 },
-                            Name = { Value = "Aug 8, 2024" },
+                            RoomID = 1234,
+                            Name = "Aug 8, 2024",
                             Playlist =
-                            {
+                            [
                                 new PlaylistItem(beatmap)
-                            },
-                            StartDate = { Value = DateTimeOffset.Now.AddMinutes(-30) },
-                            EndDate = { Value = DateTimeOffset.Now.AddSeconds(60) }
+                            ],
+                            StartDate = DateTimeOffset.Now.AddMinutes(-30),
+                            EndDate = DateTimeOffset.Now.AddSeconds(60)
                         });
                         return true;
 

osu.Game.Tests/Visual/Mods/TestSceneModAccuracyChallenge.cs

@@ -35,7 +35,7 @@ namespace osu.Game.Tests.Visual.Mods
                     MinimumAccuracy = { Value = 0.6 }
                 },
                 Autoplay = false,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = Enumerable.Range(0, 5).Select(i => new HitCircle
                     {
@@ -56,7 +56,7 @@ namespace osu.Game.Tests.Visual.Mods
                     AccuracyJudgeMode = { Value = ModAccuracyChallenge.AccuracyMode.Standard }
                 },
                 Autoplay = false,
-                Beatmap = new Beatmap
+                CreateBeatmap = () => new Beatmap
                 {
                     HitObjects = Enumerable.Range(0, 5).Select(i => new HitCircle
                     {

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
@@ -31,7 +29,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         protected readonly BindableList<MultiplayerRoomUser> MultiplayerUsers = new BindableList<MultiplayerRoomUser>();
 
-        protected MultiplayerGameplayLeaderboard Leaderboard { get; private set; }
+        protected MultiplayerGameplayLeaderboard? Leaderboard { get; private set; }
 
         protected virtual MultiplayerRoomUser CreateUser(int userId) => new MultiplayerRoomUser(userId);
 
@@ -40,7 +38,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private readonly BindableList<int> multiplayerUserIds = new BindableList<int>();
         private readonly BindableDictionary<int, SpectatorState> watchedUserStates = new BindableDictionary<int, SpectatorState>();
 
-        private OsuConfigManager config;
+        private OsuConfigManager config = null!;
 
         private readonly Mock<SpectatorClient> spectatorClient = new Mock<SpectatorClient>();
         private readonly Mock<MultiplayerClient> multiplayerClient = new Mock<MultiplayerClient>();
@@ -133,7 +131,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 LoadComponentAsync(Leaderboard = CreateLeaderboard(), Add);
             });
 
-            AddUntilStep("wait for load", () => Leaderboard.IsLoaded);
+            AddUntilStep("wait for load", () => Leaderboard!.IsLoaded);
 
             AddStep("check watch requests were sent", () =>
             {
@@ -146,7 +144,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public void TestScoreUpdates()
         {
             AddRepeatStep("update state", UpdateUserStatesRandomly, 100);
-            AddToggleStep("switch compact mode", expanded => Leaderboard.Expanded.Value = expanded);
+            AddToggleStep("switch compact mode", expanded => Leaderboard!.Expanded.Value = expanded);
         }
 
         [Test]

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;
@@ -30,16 +28,16 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         protected abstract QueueMode Mode { get; }
 
-        protected BeatmapInfo InitialBeatmap { get; private set; }
-        protected BeatmapInfo OtherBeatmap { get; private set; }
+        protected BeatmapInfo InitialBeatmap { get; private set; } = null!;
+        protected BeatmapInfo OtherBeatmap { get; private set; } = null!;
 
         protected IScreen CurrentScreen => multiplayerComponents.CurrentScreen;
         protected IScreen CurrentSubScreen => multiplayerComponents.MultiplayerScreen.CurrentSubScreen;
 
-        private BeatmapManager beatmaps;
-        private BeatmapSetInfo importedSet;
+        private BeatmapManager beatmaps = null!;
+        private BeatmapSetInfo importedSet = null!;
 
-        private TestMultiplayerComponents multiplayerComponents;
+        private TestMultiplayerComponents multiplayerComponents = null!;
 
         protected TestMultiplayerClient MultiplayerClient => multiplayerComponents.MultiplayerClient;
 
@@ -75,15 +73,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddUntilStep("wait for lounge", () => multiplayerComponents.ChildrenOfType<LoungeSubScreen>().SingleOrDefault()?.IsLoaded == true);
             AddStep("open room", () => multiplayerComponents.ChildrenOfType<LoungeSubScreen>().Single().Open(new Room
             {
-                Name = { Value = "Test Room" },
-                QueueMode = { Value = Mode },
+                Name = "Test Room",
+                QueueMode = Mode,
                 Playlist =
-                {
+                [
                     new PlaylistItem(InitialBeatmap)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             }));
 
             AddUntilStep("wait for room open", () => this.ChildrenOfType<MultiplayerMatchSubScreen>().FirstOrDefault()?.IsLoaded == true);
@@ -98,7 +96,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestCreatedWithCorrectMode()
         {
-            AddUntilStep("room created with correct mode", () => MultiplayerClient.ClientAPIRoom?.QueueMode.Value == Mode);
+            AddUntilStep("room created with correct mode", () => MultiplayerClient.ClientAPIRoom?.QueueMode == Mode);
         }
 
         protected void RunGameplay()

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using NUnit.Framework;
 using osu.Framework.Graphics;
@@ -12,7 +10,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneCreateMultiplayerMatchButton : MultiplayerTestScene
     {
-        private CreateMultiplayerMatchButton button;
+        private CreateMultiplayerMatchButton button = null!;
 
         public override void SetUpSteps()
         {
@@ -29,7 +27,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestButtonEnableStateChanges()
         {
-            IDisposable joiningRoomOperation = null;
+            IDisposable joiningRoomOperation = null!;
 
             assertButtonEnableState(true);
 

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using System.Threading;
@@ -10,6 +8,7 @@ using System.Threading.Tasks;
 using Moq;
 using NUnit.Framework;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Cursor;
 using osu.Framework.Testing;
@@ -25,14 +24,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         private readonly Room room = new Room
         {
-            HasPassword = { Value = true }
+            Password = "*"
         };
 
         [Cached]
         protected readonly OverlayColourProvider ColourProvider = new OverlayColourProvider(OverlayColourScheme.Pink);
 
-        private DrawableLoungeRoom drawableRoom;
-        private SearchTextBox searchTextBox;
+        private DrawableLoungeRoom drawableRoom = null!;
+        private SearchTextBox searchTextBox = null!;
 
         private readonly ManualResetEventSlim allowResponseCallback = new ManualResetEventSlim();
 
@@ -78,6 +77,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                         {
                             Anchor = Anchor.Centre,
                             Origin = Anchor.Centre,
+                            SelectedRoom = new Bindable<Room?>()
                         }
                     }
                 };
@@ -87,7 +87,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestFocusViaKeyboardCommit()
         {
-            DrawableLoungeRoom.PasswordEntryPopover popover = null;
+            DrawableLoungeRoom.PasswordEntryPopover? popover = null;
 
             AddAssert("search textbox has focus", () => checkFocus(searchTextBox));
             AddStep("click room twice", () =>
@@ -103,11 +103,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddStep("enter password", () => popover.ChildrenOfType<OsuPasswordTextBox>().Single().Text = "password");
             AddStep("commit via enter", () => InputManager.Key(Key.Enter));
 
-            AddAssert("popover has focus", () => checkFocus(popover));
+            AddAssert("popover has focus", () => checkFocus(popover!));
 
             AddStep("attempt another enter", () => InputManager.Key(Key.Enter));
 
-            AddAssert("popover still has focus", () => checkFocus(popover));
+            AddAssert("popover still has focus", () => checkFocus(popover!));
 
             AddStep("unblock response", () => allowResponseCallback.Set());
 
@@ -122,7 +122,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestFocusViaMouseCommit()
         {
-            DrawableLoungeRoom.PasswordEntryPopover popover = null;
+            DrawableLoungeRoom.PasswordEntryPopover? popover = null;
 
             AddAssert("search textbox has focus", () => checkFocus(searchTextBox));
             AddStep("click room twice", () =>
@@ -144,11 +144,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 InputManager.Click(MouseButton.Left);
             });
 
-            AddAssert("popover has focus", () => checkFocus(popover));
+            AddAssert("popover has focus", () => checkFocus(popover!));
 
             AddStep("attempt another click", () => InputManager.Click(MouseButton.Left));
 
-            AddAssert("popover still has focus", () => checkFocus(popover));
+            AddAssert("popover still has focus", () => checkFocus(popover!));
 
             AddStep("unblock response", () => allowResponseCallback.Set());
 

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using NUnit.Framework;
@@ -32,15 +30,40 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Cached]
         protected readonly OverlayColourProvider ColourProvider = new OverlayColourProvider(OverlayColourScheme.Plum);
 
-        private readonly Bindable<Room> selectedRoom = new Bindable<Room>();
+        private readonly Bindable<Room?> selectedRoom = new Bindable<Room?>();
 
         [Test]
         public void TestMultipleStatuses()
         {
-            FillFlowContainer rooms = null;
+            FillFlowContainer rooms = null!;
 
             AddStep("create rooms", () =>
             {
+                PlaylistItem item1 = new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo)
+                {
+                    BeatmapInfo = { StarRating = 2.5 }
+                }.BeatmapInfo);
+
+                PlaylistItem item2 = new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo)
+                {
+                    BeatmapInfo = { StarRating = 4.5 }
+                }.BeatmapInfo);
+
+                PlaylistItem item3 = new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo)
+                {
+                    BeatmapInfo =
+                    {
+                        StarRating = 2.5,
+                        Metadata =
+                        {
+                            Artist = "very very very very very very very very very long artist",
+                            ArtistUnicode = "very very very very very very very very very long artist",
+                            Title = "very very very very very very very very very very very long title",
+                            TitleUnicode = "very very very very very very very very very very very long title",
+                        }
+                    }
+                }.BeatmapInfo);
+
                 Child = rooms = new FillFlowContainer
                 {
                     Anchor = Anchor.Centre,
@@ -52,86 +75,48 @@ namespace osu.Game.Tests.Visual.Multiplayer
                     {
                         createLoungeRoom(new Room
                         {
-                            Name = { Value = "Multiplayer room" },
-                            Status = { Value = new RoomStatusOpen() },
-                            EndDate = { Value = DateTimeOffset.Now.AddDays(1) },
-                            Type = { Value = MatchType.HeadToHead },
-                            Playlist =
-                            {
-                                new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo)
-                                {
-                                    BeatmapInfo =
-                                    {
-                                        StarRating = 2.5
-                                    }
-                                }.BeatmapInfo)
-                            }
+                            Name = "Multiplayer room",
+                            Status = new RoomStatusOpen(),
+                            EndDate = DateTimeOffset.Now.AddDays(1),
+                            Type = MatchType.HeadToHead,
+                            Playlist = [item1],
+                            CurrentPlaylistItem = item1
                         }),
                         createLoungeRoom(new Room
                         {
-                            Name = { Value = "Private room" },
-                            Status = { Value = new RoomStatusOpenPrivate() },
-                            HasPassword = { Value = true },
-                            EndDate = { Value = DateTimeOffset.Now.AddDays(1) },
-                            Type = { Value = MatchType.HeadToHead },
-                            Playlist =
-                            {
-                                new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo)
-                                {
-                                    BeatmapInfo =
-                                    {
-                                        StarRating = 2.5,
-                                        Metadata =
-                                        {
-                                            Artist = "very very very very very very very very very long artist",
-                                            ArtistUnicode = "very very very very very very very very very long artist",
-                                            Title = "very very very very very very very very very very very long title",
-                                            TitleUnicode = "very very very very very very very very very very very long title",
-                                        }
-                                    }
-                                }.BeatmapInfo)
-                            }
+                            Name = "Private room",
+                            Status = new RoomStatusOpenPrivate(),
+                            Password = "*",
+                            EndDate = DateTimeOffset.Now.AddDays(1),
+                            Type = MatchType.HeadToHead,
+                            Playlist = [item3],
+                            CurrentPlaylistItem = item3
                         }),
                         createLoungeRoom(new Room
                         {
-                            Name = { Value = "Playlist room with multiple beatmaps" },
-                            Status = { Value = new RoomStatusPlaying() },
-                            EndDate = { Value = DateTimeOffset.Now.AddDays(1) },
-                            Playlist =
-                            {
-                                new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo)
-                                {
-                                    BeatmapInfo =
-                                    {
-                                        StarRating = 2.5
-                                    }
-                                }.BeatmapInfo),
-                                new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo)
-                                {
-                                    BeatmapInfo =
-                                    {
-                                        StarRating = 4.5
-                                    }
-                                }.BeatmapInfo)
-                            }
+                            Name = "Playlist room with multiple beatmaps",
+                            Status = new RoomStatusPlaying(),
+                            EndDate = DateTimeOffset.Now.AddDays(1),
+                            Playlist = [item1, item2],
+                            CurrentPlaylistItem = item1
                         }),
                         createLoungeRoom(new Room
                         {
-                            Name = { Value = "Finished room" },
-                            Status = { Value = new RoomStatusEnded() },
-                            EndDate = { Value = DateTimeOffset.Now },
+                            Name = "Finished room",
+                            Status = new RoomStatusEnded(),
+                            EndDate = DateTimeOffset.Now,
                         }),
                         createLoungeRoom(new Room
                         {
-                            Name = { Value = "Spotlight room" },
-                            Status = { Value = new RoomStatusOpen() },
-                            Category = { Value = RoomCategory.Spotlight },
+                            Name = "Spotlight room",
+                            Status = new RoomStatusOpen(),
+                            Category = RoomCategory.Spotlight,
                         }),
                         createLoungeRoom(new Room
                         {
-                            Name = { Value = "Featured artist room" },
-                            Status = { Value = new RoomStatusOpen() },
-                            Category = { Value = RoomCategory.FeaturedArtist },
+                            Name = "Featured artist room",
+                            Status = new RoomStatusOpen(),
+                            Category = RoomCategory.FeaturedArtist,
                         }),
                     }
                 };
@@ -145,24 +130,24 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestEnableAndDisablePassword()
         {
-            DrawableRoom drawableRoom = null;
-            Room room = null;
+            DrawableRoom drawableRoom = null!;
+            Room room = null!;
 
             AddStep("create room", () => Child = drawableRoom = createLoungeRoom(room = new Room
             {
-                Name = { Value = "Room with password" },
-                Status = { Value = new RoomStatusOpen() },
-                Type = { Value = MatchType.HeadToHead },
+                Name = "Room with password",
+                Status = new RoomStatusOpen(),
+                Type = MatchType.HeadToHead,
             }));
 
             AddUntilStep("wait for panel load", () => drawableRoom.ChildrenOfType<DrawableRoomParticipantsList>().Any());
 
             AddAssert("password icon hidden", () => Precision.AlmostEquals(0, drawableRoom.ChildrenOfType<DrawableRoom.PasswordProtectedIcon>().Single().Alpha));
 
-            AddStep("set password", () => room.Password.Value = "password");
+            AddStep("set password", () => room.Password = "password");
             AddAssert("password icon visible", () => Precision.AlmostEquals(1, drawableRoom.ChildrenOfType<DrawableRoom.PasswordProtectedIcon>().Single().Alpha));
 
-            AddStep("unset password", () => room.Password.Value = string.Empty);
+            AddStep("unset password", () => room.Password = string.Empty);
             AddAssert("password icon hidden", () => Precision.AlmostEquals(0, drawableRoom.ChildrenOfType<DrawableRoom.PasswordProtectedIcon>().Single().Alpha));
         }
 
@@ -179,43 +164,52 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 {
                     new DrawableMatchRoom(new Room
                     {
-                        Name = { Value = "A host-only room" },
-                        QueueMode = { Value = QueueMode.HostOnly },
-                        Type = { Value = MatchType.HeadToHead }
-                    }),
+                        Name = "A host-only room",
+                        QueueMode = QueueMode.HostOnly,
+                        Type = MatchType.HeadToHead,
+                    })
+                    {
+                        SelectedItem = new Bindable<PlaylistItem?>()
+                    },
                     new DrawableMatchRoom(new Room
                     {
-                        Name = { Value = "An all-players, team-versus room" },
-                        QueueMode = { Value = QueueMode.AllPlayers },
-                        Type = { Value = MatchType.TeamVersus }
-                    }),
+                        Name = "An all-players, team-versus room",
+                        QueueMode = QueueMode.AllPlayers,
+                        Type = MatchType.TeamVersus
+                    })
+                    {
+                        SelectedItem = new Bindable<PlaylistItem?>()
+                    },
                     new DrawableMatchRoom(new Room
                     {
-                        Name = { Value = "A round-robin room" },
-                        QueueMode = { Value = QueueMode.AllPlayersRoundRobin },
-                        Type = { Value = MatchType.HeadToHead }
-                    }),
+                        Name = "A round-robin room",
+                        QueueMode = QueueMode.AllPlayersRoundRobin,
+                        Type = MatchType.HeadToHead
+                    })
+                    {
+                        SelectedItem = new Bindable<PlaylistItem?>()
+                    },
                 }
             });
         }
 
         private DrawableRoom createLoungeRoom(Room room)
         {
-            room.Host.Value ??= new APIUser { Username = "peppy", Id = 2 };
+            room.Host ??= new APIUser { Username = "peppy", Id = 2 };
 
             if (room.RecentParticipants.Count == 0)
             {
-                room.RecentParticipants.AddRange(Enumerable.Range(0, 20).Select(i => new APIUser
+                room.RecentParticipants = Enumerable.Range(0, 20).Select(i => new APIUser
                 {
                     Id = i,
                     Username = $"User {i}"
-                }));
+                }).ToArray();
             }
 
             return new DrawableLoungeRoom(room)
             {
                 MatchingFilter = true,
-                SelectedRoom = { BindTarget = selectedRoom }
+                SelectedRoom = selectedRoom
             };
         }
     }

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Graphics;
@@ -17,7 +15,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneDrawableRoomParticipantsList : OnlinePlayTestScene
     {
-        private DrawableRoomParticipantsList list;
+        private DrawableRoomParticipantsList list = null!;
 
         public override void SetUpSteps()
         {
@@ -27,18 +25,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 SelectedRoom.Value = new Room
                 {
-                    Name = { Value = "test room" },
-                    Host =
+                    Name = "test room",
+                    Host = new APIUser
                     {
-                        Value = new APIUser
-                        {
-                            Id = 2,
-                            Username = "peppy",
-                        }
+                        Id = 2,
+                        Username = "peppy",
                     }
                 };
 
-                Child = list = new DrawableRoomParticipantsList
+                Child = list = new DrawableRoomParticipantsList(SelectedRoom.Value)
                 {
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,
@@ -124,7 +119,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddAssert("4 circles displayed", () => list.ChildrenOfType<UpdateableAvatar>().Count() == 4);
             AddAssert("46 hidden users", () => list.ChildrenOfType<DrawableRoomParticipantsList.HiddenUserCount>().Single().Count == 46);
 
-            AddStep("remove from end", () => removeUserAt(SelectedRoom.Value.RecentParticipants.Count - 1));
+            AddStep("remove from end", () => removeUserAt(SelectedRoom.Value!.RecentParticipants.Count - 1));
             AddAssert("4 circles displayed", () => list.ChildrenOfType<UpdateableAvatar>().Count() == 4);
             AddAssert("45 hidden users", () => list.ChildrenOfType<DrawableRoomParticipantsList.HiddenUserCount>().Single().Count == 45);
 
@@ -143,18 +138,18 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         private void addUser(int id)
         {
-            SelectedRoom.Value.RecentParticipants.Add(new APIUser
+            SelectedRoom.Value!.RecentParticipants = SelectedRoom.Value!.RecentParticipants.Append(new APIUser
             {
                 Id = id,
                 Username = $"User {id}"
-            });
-            SelectedRoom.Value.ParticipantCount.Value++;
+            }).ToArray();
+            SelectedRoom.Value!.ParticipantCount++;
         }
 
         private void removeUserAt(int index)
         {
-            SelectedRoom.Value.RecentParticipants.RemoveAt(index);
-            SelectedRoom.Value.ParticipantCount.Value--;
+            SelectedRoom.Value!.RecentParticipants = SelectedRoom.Value!.RecentParticipants.Where(u => !u.Equals(SelectedRoom.Value!.RecentParticipants[index])).ToArray();
+            SelectedRoom.Value!.ParticipantCount--;
         }
     }
 }

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -39,9 +37,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneDrawableRoomPlaylist : MultiplayerTestScene
     {
-        private TestPlaylist playlist;
-
-        private BeatmapManager manager;
+        private TestPlaylist playlist = null!;
+        private BeatmapManager manager = null!;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
@@ -199,14 +196,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestDownloadButtonHiddenWhenBeatmapExists()
         {
-            Live<BeatmapSetInfo> imported = null;
+            Live<BeatmapSetInfo> imported = null!;
 
             AddStep("import beatmap", () =>
             {
                 var beatmap = new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo;
 
                 Debug.Assert(beatmap.BeatmapSet != null);
-                imported = manager.Import(beatmap.BeatmapSet);
+                imported = manager.Import(beatmap.BeatmapSet)!;
             });
 
             createPlaylistWithBeatmaps(() => imported.PerformRead(s => s.Beatmaps.Detach()));
@@ -378,7 +375,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             }
         });
 
-        private void createPlaylist(Action<TestPlaylist> setupPlaylist = null)
+        private void createPlaylist(Action<TestPlaylist>? setupPlaylist = null)
         {
             AddStep("create playlist", () =>
             {

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -26,9 +24,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneFreeModSelectOverlay : MultiplayerTestScene
     {
-        private FreeModSelectOverlay freeModSelectOverlay;
-        private FooterButtonFreeMods footerButtonFreeMods;
-        private ScreenFooter footer;
+        private FreeModSelectOverlay freeModSelectOverlay = null!;
+        private FooterButtonFreeMods footerButtonFreeMods = null!;
+        private ScreenFooter footer = null!;
         private readonly Bindable<Dictionary<ModType, IReadOnlyList<Mod>>> availableMods = new Bindable<Dictionary<ModType, IReadOnlyList<Mod>>>();
 
         [BackgroundDependencyLoader]
@@ -49,8 +47,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddToggleStep("toggle visibility", visible =>
             {
-                if (freeModSelectOverlay != null)
-                    freeModSelectOverlay.State.Value = visible ? Visibility.Visible : Visibility.Hidden;
+                freeModSelectOverlay.State.Value = visible ? Visibility.Visible : Visibility.Hidden;
             });
         }
 

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using Moq;
 using NUnit.Framework;
@@ -20,7 +18,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneGameplayChatDisplay : OsuManualInputManagerTestScene
     {
-        private GameplayChatDisplay chatDisplay;
+        private GameplayChatDisplay chatDisplay = null!;
 
         [Cached(typeof(ILocalUserPlayInfo))]
         private ILocalUserPlayInfo localUserInfo;

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using NUnit.Framework;
@@ -46,7 +44,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 QueueMode = QueueMode.AllPlayers
             }).WaitSafely());
 
-            AddUntilStep("api room updated", () => MultiplayerClient.ClientAPIRoom?.QueueMode.Value == QueueMode.AllPlayers);
+            AddUntilStep("api room updated", () => MultiplayerClient.ClientAPIRoom?.QueueMode == QueueMode.AllPlayers);
         }
 
         [Test]
@@ -70,13 +68,13 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             RunGameplay();
 
-            IBeatmapInfo firstBeatmap = null;
-            AddStep("get first playlist item beatmap", () => firstBeatmap = MultiplayerClient.ServerAPIRoom?.Playlist[0].Beatmap);
+            IBeatmapInfo firstBeatmap = null!;
+            AddStep("get first playlist item beatmap", () => firstBeatmap = MultiplayerClient.ServerAPIRoom!.Playlist[0].Beatmap);
 
             selectNewItem(() => OtherBeatmap);
 
-            AddUntilStep("first playlist item hasn't changed", () => MultiplayerClient.ServerAPIRoom?.Playlist[0].Beatmap == firstBeatmap);
-            AddUntilStep("second playlist item changed", () => MultiplayerClient.ClientAPIRoom?.Playlist[1].Beatmap != firstBeatmap);
+            AddUntilStep("first playlist item hasn't changed", () => MultiplayerClient.ServerAPIRoom!.Playlist[0].Beatmap == firstBeatmap);
+            AddUntilStep("second playlist item changed", () => MultiplayerClient.ClientAPIRoom!.Playlist[1].Beatmap != firstBeatmap);
         }
 
         [Test]
@@ -103,7 +101,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddUntilStep("wait for song select", () => CurrentSubScreen is Screens.Select.SongSelect select && select.BeatmapSetsLoaded);
 
-            BeatmapInfo otherBeatmap = null;
+            BeatmapInfo otherBeatmap = null!;
             AddStep("select other beatmap", () => ((Screens.Select.SongSelect)CurrentSubScreen).FinaliseSelection(otherBeatmap = beatmap()));
 
             AddUntilStep("wait for return to match", () => CurrentSubScreen is MultiplayerMatchSubScreen);

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Graphics;
@@ -23,7 +21,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         protected new TestRoomManager RoomManager => (TestRoomManager)base.RoomManager;
 
-        private RoomsContainer container;
+        private RoomsContainer container = null!;
 
         public override void SetUpSteps()
         {
@@ -55,20 +53,20 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddAssert("has 5 rooms", () => container.Rooms.Count == 5);
 
             AddAssert("all spotlights at top", () => container.Rooms
-                                                              .SkipWhile(r => r.Room.Category.Value == RoomCategory.Spotlight)
-                                                              .All(r => r.Room.Category.Value == RoomCategory.Normal));
+                                                              .SkipWhile(r => r.Room.Category == RoomCategory.Spotlight)
+                                                              .All(r => r.Room.Category == RoomCategory.Normal));
 
-            AddStep("remove first room", () => RoomManager.RemoveRoom(RoomManager.Rooms.First(r => r.RoomID.Value == 0)));
+            AddStep("remove first room", () => RoomManager.RemoveRoom(RoomManager.Rooms.First(r => r.RoomID == 0)));
             AddAssert("has 4 rooms", () => container.Rooms.Count == 4);
-            AddAssert("first room removed", () => container.Rooms.All(r => r.Room.RoomID.Value != 0));
+            AddAssert("first room removed", () => container.Rooms.All(r => r.Room.RoomID != 0));
 
             AddStep("select first room", () => container.Rooms.First().TriggerClick());
-            AddAssert("first spotlight selected", () => checkRoomSelected(RoomManager.Rooms.First(r => r.Category.Value == RoomCategory.Spotlight)));
+            AddAssert("first spotlight selected", () => checkRoomSelected(RoomManager.Rooms.First(r => r.Category == RoomCategory.Spotlight)));
 
-            AddStep("remove last room", () => RoomManager.RemoveRoom(RoomManager.Rooms.MinBy(r => r.RoomID?.Value)));
-            AddAssert("first spotlight still selected", () => checkRoomSelected(RoomManager.Rooms.First(r => r.Category.Value == RoomCategory.Spotlight)));
+            AddStep("remove last room", () => RoomManager.RemoveRoom(RoomManager.Rooms.MinBy(r => r.RoomID)!));
+            AddAssert("first spotlight still selected", () => checkRoomSelected(RoomManager.Rooms.First(r => r.Category == RoomCategory.Spotlight)));
 
-            AddStep("remove spotlight room", () => RoomManager.RemoveRoom(RoomManager.Rooms.Single(r => r.Category.Value == RoomCategory.Spotlight)));
+            AddStep("remove spotlight room", () => RoomManager.RemoveRoom(RoomManager.Rooms.Single(r => r.Category == RoomCategory.Spotlight)));
             AddAssert("selection vacated", () => checkRoomSelected(null));
         }
 
@@ -157,7 +155,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddStep("add rooms", () => RoomManager.AddRooms(3, new CatchRuleset().RulesetInfo));
 
             // Todo: What even is this case...?
-            AddStep("set empty filter criteria", () => container.Filter.Value = null);
+            AddStep("set empty filter criteria", () => container.Filter.Value = new FilterCriteria());
             AddUntilStep("5 rooms visible", () => container.Rooms.Count(r => r.IsPresent) == 5);
 
             AddStep("filter osu! rooms", () => container.Filter.Value = new FilterCriteria { Ruleset = new OsuRuleset().RulesetInfo });
@@ -182,11 +180,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("filter public rooms", () => container.Filter.Value = new FilterCriteria { Permissions = RoomPermissionsFilter.Public });
 
-            AddUntilStep("private room hidden", () => container.Rooms.All(r => !r.Room.HasPassword.Value));
+            AddUntilStep("private room hidden", () => container.Rooms.All(r => !r.Room.HasPassword));
 
             AddStep("filter private rooms", () => container.Filter.Value = new FilterCriteria { Permissions = RoomPermissionsFilter.Private });
 
-            AddUntilStep("public room hidden", () => container.Rooms.All(r => r.Room.HasPassword.Value));
+            AddUntilStep("public room hidden", () => container.Rooms.All(r => r.Room.HasPassword));
         }
 
         [Test]
@@ -195,9 +193,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddStep("add rooms", () => RoomManager.AddRooms(3, withPassword: true));
         }
 
-        private bool checkRoomSelected(Room room) => SelectedRoom.Value == room;
+        private bool checkRoomSelected(Room? room) => SelectedRoom.Value == room;
 
-        private Room getRoomInFlow(int index) =>
+        private Room? getRoomInFlow(int index) =>
             (container.ChildrenOfType<FillFlowContainer<DrawableLoungeRoom>>().First().FlowingChildren.ElementAt(index) as DrawableRoom)?.Room;
     }
 }

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

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Linq;
 using osu.Framework.Graphics;
 using osu.Game.Online.API;
 using osu.Game.Online.Rooms;
@@ -23,7 +24,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 SelectedRoom.Value = new Room();
 
-                Child = new MatchBeatmapDetailArea
+                Child = new MatchBeatmapDetailArea(SelectedRoom.Value)
                 {
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,
@@ -35,7 +36,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         private void createNewItem()
         {
-            SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
+            SelectedRoom.Value!.Playlist = SelectedRoom.Value.Playlist.Append(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
             {
                 ID = SelectedRoom.Value.Playlist.Count,
                 RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
@@ -45,7 +46,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                     new APIMod(new OsuModDoubleTime()),
                     new APIMod(new OsuModAutoplay())
                 }
-            });
+            }).ToArray();
         }
     }
 }

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

@@ -61,9 +61,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("create leaderboard", () =>
             {
-                SelectedRoom.Value = new Room { RoomID = { Value = 3 } };
+                SelectedRoom.Value = new Room { RoomID = 3 };
 
-                Child = new MatchLeaderboard
+                Child = new MatchLeaderboard(SelectedRoom.Value)
                 {
                     Origin = Anchor.Centre,
                     Anchor = Anchor.Centre,

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

@@ -43,12 +43,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         private OsuButton readyButton => control.ChildrenOfType<OsuButton>().Single();
 
-        [Cached(typeof(IBindable<PlaylistItem>))]
-        private readonly Bindable<PlaylistItem> currentItem = new Bindable<PlaylistItem>();
-
-        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent) =>
-            new CachedModelDependencyContainer<Room>(base.CreateChildDependencies(parent)) { Model = { BindTarget = room } };
-
         [BackgroundDependencyLoader]
         private void load()
         {
@@ -107,31 +101,33 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [SetUpSteps]
         public void SetUpSteps()
         {
+            PlaylistItem item = null!;
+
             AddStep("reset state", () =>
             {
                 multiplayerClient.Invocations.Clear();
 
                 beatmapAvailability.Value = BeatmapAvailability.LocallyAvailable();
 
-                currentItem.Value = new PlaylistItem(Beatmap.Value.BeatmapInfo)
+                item = new PlaylistItem(Beatmap.Value.BeatmapInfo)
                 {
                     RulesetID = Beatmap.Value.BeatmapInfo.Ruleset.OnlineID
                 };
 
                 room.Value = new Room
                 {
-                    Playlist = { currentItem.Value },
-                    CurrentPlaylistItem = { BindTarget = currentItem }
+                    Playlist = [item],
+                    CurrentPlaylistItem = item
                 };
 
-                localUser = new MultiplayerRoomUser(API.LocalUser.Value.Id) { User = API.LocalUser.Value };
+                localUser = new MultiplayerRoomUser(API.LocalUser.Value.Id)
+                {
+                    User = API.LocalUser.Value
+                };
 
                 multiplayerRoom = new MultiplayerRoom(0)
                 {
-                    Playlist =
-                    {
-                        TestMultiplayerClient.CreateMultiplayerPlaylistItem(currentItem.Value),
-                    },
+                    Playlist = { TestMultiplayerClient.CreateMultiplayerPlaylistItem(item) },
                     Users = { localUser },
                     Host = localUser,
                 };
@@ -144,6 +140,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,
                     Size = new Vector2(250, 50),
+                    SelectedItem = new Bindable<PlaylistItem?>(item)
                 };
             });
         }

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
@@ -18,8 +16,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiSpectatorLeaderboard : MultiplayerTestScene
     {
-        private Dictionary<int, ManualClock> clocks;
-        private MultiSpectatorLeaderboard leaderboard;
+        private Dictionary<int, ManualClock> clocks = null!;
+        private MultiSpectatorLeaderboard? leaderboard;
 
         [SetUpSteps]
         public override void SetUpSteps()
@@ -55,13 +53,13 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 }, Add);
             });
 
-            AddUntilStep("wait for load", () => leaderboard.IsLoaded);
+            AddUntilStep("wait for load", () => leaderboard!.IsLoaded);
             AddUntilStep("wait for user population", () => leaderboard.ChildrenOfType<GameplayLeaderboardScore>().Count() == 2);
 
             AddStep("add clock sources", () =>
             {
                 foreach ((int userId, var clock) in clocks)
-                    leaderboard.AddClock(userId, clock);
+                    leaderboard!.AddClock(userId, clock);
             });
         }
 

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

@@ -455,7 +455,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
                 applyToBeatmap?.Invoke(Beatmap.Value);
 
-                LoadScreen(spectatorScreen = new MultiSpectatorScreen(SelectedRoom.Value, playingUsers.ToArray()));
+                LoadScreen(spectatorScreen = new MultiSpectatorScreen(SelectedRoom.Value!, playingUsers.ToArray()));
             });
 
             AddUntilStep("wait for screen load", () => spectatorScreen.LoadState == LoadState.Loaded && (!waitForPlayerLoad || spectatorScreen.AllPlayersLoaded));

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

@@ -103,14 +103,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddRepeatStep("random stuff happens", performRandomAction, 30);
@@ -238,17 +238,17 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
-            AddUntilStep("Check participant count correct", () => multiplayerClient.ClientAPIRoom?.ParticipantCount.Value == 1);
+            AddUntilStep("Check participant count correct", () => multiplayerClient.ClientAPIRoom?.ParticipantCount == 1);
             AddUntilStep("Check participant list contains user", () => multiplayerClient.ClientAPIRoom?.RecentParticipants.Count(u => u.Id == API.LocalUser.Value.Id) == 1);
         }
 
@@ -259,14 +259,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 roomManager.AddServerSideRoom(new Room
                 {
-                    Name = { Value = "Test Room" },
+                    Name = "Test Room",
                     Playlist =
-                    {
+                    [
                         new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                         {
                             RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                         }
-                    }
+                    ]
                 }, API.LocalUser.Value);
             });
 
@@ -288,14 +288,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 roomManager.AddServerSideRoom(new Room
                 {
-                    Name = { Value = "Test Room" },
+                    Name = "Test Room",
                     Playlist =
-                    {
+                    [
                         new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                         {
                             RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                         }
-                    }
+                    ]
                 }, API.LocalUser.Value);
             });
 
@@ -308,7 +308,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddUntilStep("wait for room open", () => this.ChildrenOfType<MultiplayerMatchSubScreen>().FirstOrDefault()?.IsLoaded == true);
             AddUntilStep("wait for join", () => multiplayerClient.RoomJoined);
 
-            AddUntilStep("Check participant count correct", () => multiplayerClient.ClientAPIRoom?.ParticipantCount.Value == 1);
+            AddUntilStep("Check participant count correct", () => multiplayerClient.ClientAPIRoom?.ParticipantCount == 1);
             AddUntilStep("Check participant list contains user", () => multiplayerClient.ClientAPIRoom?.RecentParticipants.Count(u => u.Id == API.LocalUser.Value.Id) == 1);
         }
 
@@ -317,18 +317,18 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                Password = { Value = "password" },
+                Name = "Test Room",
+                Password = "password",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
-            AddUntilStep("room has password", () => multiplayerClient.ClientAPIRoom?.Password.Value == "password");
+            AddUntilStep("room has password", () => multiplayerClient.ClientAPIRoom?.Password == "password");
         }
 
         [Test]
@@ -338,15 +338,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 roomManager.AddServerSideRoom(new Room
                 {
-                    Name = { Value = "Test Room" },
-                    Password = { Value = "password" },
+                    Name = "Test Room",
+                    Password = "password",
                     Playlist =
-                    {
+                    [
                         new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                         {
                             RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                         }
-                    }
+                    ]
                 }, API.LocalUser.Value);
             });
 
@@ -370,19 +370,19 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                Password = { Value = "password" },
+                Name = "Test Room",
+                Password = "password",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddStep("change password", () => multiplayerClient.ChangeSettings(password: "password2"));
-            AddUntilStep("local password changed", () => multiplayerClient.ClientAPIRoom?.Password.Value == "password2");
+            AddUntilStep("local password changed", () => multiplayerClient.ClientAPIRoom?.Password == "password2");
         }
 
         [Test]
@@ -401,14 +401,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             pressReadyButton();
@@ -430,8 +430,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 };
                 return new Room
                 {
-                    Name = { Value = "Test Room" },
-                    Playlist = { item }
+                    Name = "Test Room",
+                    Playlist = [item]
                 };
             });
 
@@ -471,8 +471,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 };
                 return new Room
                 {
-                    Name = { Value = "Test Room" },
-                    Playlist = { item }
+                    Name = "Test Room",
+                    Playlist = [item]
                 };
             });
 
@@ -512,8 +512,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 };
                 return new Room
                 {
-                    Name = { Value = "Test Room" },
-                    Playlist = { item }
+                    Name = "Test Room",
+                    Playlist = [item]
                 };
             });
 
@@ -548,14 +548,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddStep("join other user (ready, host)", () =>
@@ -581,14 +581,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddStep("delete beatmap", () => beatmaps.Delete(importedSet));
@@ -620,14 +620,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddStep("disconnect", () => multiplayerClient.Disconnect());
@@ -639,15 +639,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                         AllowedMods = new[] { new APIMod(new OsuModHidden()) }
                     }
-                }
+                ]
             });
 
             AddStep("open mod overlay", () => this.ChildrenOfType<UserModSelectButton>().Single().TriggerClick());
@@ -679,14 +679,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             enterGameplay();
@@ -724,14 +724,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             enterGameplay();
@@ -754,14 +754,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             pressReadyButton();
@@ -791,15 +791,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 roomManager.AddServerSideRoom(new Room
                 {
-                    Name = { Value = "Test Room" },
-                    QueueMode = { Value = QueueMode.AllPlayers },
+                    Name = "Test Room",
+                    QueueMode = QueueMode.AllPlayers,
                     Playlist =
-                    {
+                    [
                         new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                         {
                             RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                         }
-                    }
+                    ]
                 }, API.LocalUser.Value);
             });
 
@@ -810,12 +810,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddStep("disable polling", () => this.ChildrenOfType<ListingPollingComponent>().Single().TimeBetweenPolls.Value = 0);
             AddStep("change server-side settings", () =>
             {
-                roomManager.ServerSideRooms[0].Name.Value = "New name";
-                roomManager.ServerSideRooms[0].Playlist.Add(new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
-                {
-                    ID = 2,
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
-                });
+                roomManager.ServerSideRooms[0].Name = "New name";
+                roomManager.ServerSideRooms[0].Playlist =
+                [
+                    new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
+                    {
+                        ID = 2,
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
+                    }
+                ];
             });
 
             AddStep("join room", () => InputManager.Key(Key.Enter));
@@ -825,8 +828,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddAssert("local room has correct settings", () =>
             {
                 var localRoom = this.ChildrenOfType<MultiplayerMatchSubScreen>().Single().Room;
-                return localRoom.Name.Value == roomManager.ServerSideRooms[0].Name.Value
-                       && localRoom.Playlist.SequenceEqual(roomManager.ServerSideRooms[0].Playlist);
+                return localRoom.Name == roomManager.ServerSideRooms[0].Name && localRoom.Playlist.Single().ID == 2;
             });
         }
 
@@ -836,15 +838,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                QueueMode = { Value = QueueMode.AllPlayers },
+                Name = "Test Room",
+                QueueMode = QueueMode.AllPlayers,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             AddStep("set spectating state", () => multiplayerClient.ChangeUserState(API.LocalUser.Value.OnlineID, MultiplayerUserState.Spectating));
@@ -872,15 +874,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                QueueMode = { Value = QueueMode.AllPlayers },
+                Name = "Test Room",
+                QueueMode = QueueMode.AllPlayers,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             AddStep("set spectating state", () => multiplayerClient.ChangeUserState(API.LocalUser.Value.OnlineID, MultiplayerUserState.Spectating));
@@ -911,15 +913,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                QueueMode = { Value = QueueMode.AllPlayers },
+                Name = "Test Room",
+                QueueMode = QueueMode.AllPlayers,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             enterGameplay();
@@ -942,15 +944,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                QueueMode = { Value = QueueMode.AllPlayers },
+                Name = "Test Room",
+                QueueMode = QueueMode.AllPlayers,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             enterGameplay();
@@ -976,14 +978,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddStep("join other user and make host", () =>
@@ -1022,10 +1024,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                QueueMode = { Value = QueueMode.AllPlayers },
+                Name = "Test Room",
+                QueueMode = QueueMode.AllPlayers,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
@@ -1036,7 +1038,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                         RulesetID = new TaikoRuleset().RulesetInfo.OnlineID,
                         AllowedMods = new[] { new APIMod { Acronym = "HD" } },
                     },
-                }
+                ]
             });
 
             AddStep("select hidden", () => multiplayerClient.ChangeUserMods(new[] { new APIMod { Acronym = "HD" } }));

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

@@ -37,10 +37,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestPerUserMods()
         {
-            AddStep("first user has no mods", () => Assert.That(((TestLeaderboard)Leaderboard).UserMods[0], Is.Empty));
+            AddStep("first user has no mods", () => Assert.That(((TestLeaderboard)Leaderboard!).UserMods[0], Is.Empty));
             AddStep("last user has NF mod", () =>
             {
-                Assert.That(((TestLeaderboard)Leaderboard).UserMods[TOTAL_USERS - 1], Has.One.Items);
+                Assert.That(((TestLeaderboard)Leaderboard!).UserMods[TOTAL_USERS - 1], Has.One.Items);
                 Assert.That(((TestLeaderboard)Leaderboard).UserMods[TOTAL_USERS - 1].Single(), Is.TypeOf<OsuModNoFail>());
             });
         }

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

@@ -39,7 +39,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 LoadComponentAsync(new MatchScoreDisplay
                 {
-                    Team1Score = { BindTarget = Leaderboard.TeamScores[0] },
+                    Team1Score = { BindTarget = Leaderboard!.TeamScores[0] },
                     Team2Score = { BindTarget = Leaderboard.TeamScores[1] }
                 }, Add);
 

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Graphics.Containers;
@@ -22,10 +20,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         protected new TestRoomManager RoomManager => (TestRoomManager)base.RoomManager;
 
-        private LoungeSubScreen loungeScreen;
-
-        private Room lastJoinedRoom;
-        private string lastJoinedPassword;
+        private LoungeSubScreen loungeScreen = null!;
+        private Room? lastJoinedRoom;
+        private string? lastJoinedPassword;
 
         public override void SetUpSteps()
         {
@@ -87,7 +84,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestJoinRoomWithIncorrectPasswordViaButton()
         {
-            DrawableLoungeRoom.PasswordEntryPopover passwordEntryPopover = null;
+            DrawableLoungeRoom.PasswordEntryPopover? passwordEntryPopover = null;
 
             AddStep("add room", () => RoomManager.AddRooms(1, withPassword: true));
             AddStep("select room", () => InputManager.Key(Key.Down));
@@ -97,14 +94,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddStep("press join room button", () => passwordEntryPopover.ChildrenOfType<OsuButton>().First().TriggerClick());
 
             AddAssert("room not joined", () => loungeScreen.IsCurrentScreen());
-            AddUntilStep("password prompt still visible", () => passwordEntryPopover.State.Value == Visibility.Visible);
+            AddUntilStep("password prompt still visible", () => passwordEntryPopover!.State.Value == Visibility.Visible);
             AddAssert("textbox still focused", () => InputManager.FocusedDrawable is OsuPasswordTextBox);
         }
 
         [Test]
         public void TestJoinRoomWithIncorrectPasswordViaEnter()
         {
-            DrawableLoungeRoom.PasswordEntryPopover passwordEntryPopover = null;
+            DrawableLoungeRoom.PasswordEntryPopover? passwordEntryPopover = null;
 
             AddStep("add room", () => RoomManager.AddRooms(1, withPassword: true));
             AddStep("select room", () => InputManager.Key(Key.Down));
@@ -114,14 +111,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddStep("press enter", () => InputManager.Key(Key.Enter));
 
             AddAssert("room not joined", () => loungeScreen.IsCurrentScreen());
-            AddUntilStep("password prompt still visible", () => passwordEntryPopover.State.Value == Visibility.Visible);
+            AddUntilStep("password prompt still visible", () => passwordEntryPopover!.State.Value == Visibility.Visible);
             AddAssert("textbox still focused", () => InputManager.FocusedDrawable is OsuPasswordTextBox);
         }
 
         [Test]
         public void TestJoinRoomWithCorrectPassword()
         {
-            DrawableLoungeRoom.PasswordEntryPopover passwordEntryPopover = null;
+            DrawableLoungeRoom.PasswordEntryPopover? passwordEntryPopover = null;
 
             AddStep("add room", () => RoomManager.AddRooms(1, withPassword: true));
             AddStep("select room", () => InputManager.Key(Key.Down));
@@ -137,7 +134,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestJoinRoomWithPasswordViaKeyboardOnly()
         {
-            DrawableLoungeRoom.PasswordEntryPopover passwordEntryPopover = null;
+            DrawableLoungeRoom.PasswordEntryPopover? passwordEntryPopover = null;
 
             AddStep("add room", () => RoomManager.AddRooms(1, withPassword: true));
             AddStep("select room", () => InputManager.Key(Key.Down));
@@ -150,7 +147,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddAssert("room join password correct", () => lastJoinedPassword == "password");
         }
 
-        private void onRoomJoined(Room room, string password)
+        private void onRoomJoined(Room room, string? password)
         {
             lastJoinedRoom = room;
             lastJoinedPassword = password;

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

@@ -1,7 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -13,9 +12,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerMatchFooter : MultiplayerTestScene
     {
-        [Cached(typeof(IBindable<PlaylistItem>))]
-        private readonly Bindable<PlaylistItem> currentItem = new Bindable<PlaylistItem>();
-
         public override void SetUpSteps()
         {
             base.SetUpSteps();
@@ -33,7 +29,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
                         Origin = Anchor.Centre,
                         RelativeSizeAxes = Axes.X,
                         Height = 50,
-                        Child = new MultiplayerMatchFooter()
+                        Child = new MultiplayerMatchFooter
+                        {
+                            SelectedItem = new Bindable<PlaylistItem?>()
+                        }
                     }
                 };
             });

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

@@ -1,12 +1,9 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using JetBrains.Annotations;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
@@ -35,17 +32,16 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerMatchSongSelect : MultiplayerTestScene
     {
-        private BeatmapManager manager;
-        private RulesetStore rulesets;
+        private BeatmapManager manager = null!;
+        private RulesetStore rulesets = null!;
 
-        private IList<BeatmapInfo> beatmaps => importedBeatmapSet?.PerformRead(s => s.Beatmaps) ?? new List<BeatmapInfo>();
+        private IList<BeatmapInfo> beatmaps => importedBeatmapSet.PerformRead(s => s.Beatmaps);
 
-        private TestMultiplayerMatchSongSelect songSelect;
-
-        private Live<BeatmapSetInfo> importedBeatmapSet;
+        private TestMultiplayerMatchSongSelect songSelect = null!;
+        private Live<BeatmapSetInfo> importedBeatmapSet = null!;
 
         [Resolved]
-        private OsuConfigManager configManager { get; set; }
+        private OsuConfigManager configManager { get; set; } = null!;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
@@ -57,7 +53,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             Dependencies.Cache(detachedBeatmapStore = new DetachedBeatmapStore());
             Dependencies.Cache(Realm);
 
-            importedBeatmapSet = manager.Import(TestResources.CreateTestBeatmapSetInfo(8, rulesets.AvailableRulesets.ToArray()));
+            importedBeatmapSet = manager.Import(TestResources.CreateTestBeatmapSetInfo(8, rulesets.AvailableRulesets.ToArray()))!;
 
             Add(detachedBeatmapStore);
         }
@@ -71,7 +67,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 SelectedMods.SetDefault();
             });
 
-            AddStep("create song select", () => LoadScreen(songSelect = new TestMultiplayerMatchSongSelect(SelectedRoom.Value)));
+            AddStep("create song select", () => LoadScreen(songSelect = new TestMultiplayerMatchSongSelect(SelectedRoom.Value!)));
             AddUntilStep("wait for present", () => songSelect.IsCurrentScreen() && songSelect.BeatmapSetsLoaded);
         }
 
@@ -88,7 +84,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestBeatmapConfirmed()
         {
-            BeatmapInfo selectedBeatmap = null;
+            BeatmapInfo selectedBeatmap = null!;
 
             setUp();
 
@@ -117,8 +113,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
             setUp();
 
             AddStep("change ruleset", () => Ruleset.Value = new OsuRuleset().RulesetInfo);
-            AddStep($"select {allowedMod.ReadableName()} as allowed", () => songSelect.FreeMods.Value = new[] { (Mod)Activator.CreateInstance(allowedMod) });
-            AddStep($"select {requiredMod.ReadableName()} as required", () => songSelect.Mods.Value = new[] { (Mod)Activator.CreateInstance(requiredMod) });
+            AddStep($"select {allowedMod.ReadableName()} as allowed", () => songSelect.FreeMods.Value = new[] { (Mod)Activator.CreateInstance(allowedMod)! });
+            AddStep($"select {requiredMod.ReadableName()} as required", () => songSelect.Mods.Value = new[] { (Mod)Activator.CreateInstance(requiredMod)! });
 
             AddAssert("freemods empty", () => songSelect.FreeMods.Value.Count == 0);
 
@@ -141,7 +137,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("create song select", () =>
             {
-                SelectedRoom.Value.Playlist.Single().RulesetID = 2;
+                SelectedRoom.Value!.Playlist.Single().RulesetID = 2;
                 songSelect = new TestMultiplayerMatchSongSelect(SelectedRoom.Value, SelectedRoom.Value.Playlist.Single());
                 songSelect.OnLoadComplete += _ => Ruleset.Value = new TaikoRuleset().RulesetInfo;
                 LoadScreen(songSelect);
@@ -171,7 +167,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             public new BeatmapCarousel Carousel => base.Carousel;
 
-            public TestMultiplayerMatchSongSelect(Room room, [CanBeNull] PlaylistItem itemToEdit = null)
+            public TestMultiplayerMatchSongSelect(Room room, PlaylistItem? itemToEdit = null)
                 : base(room, itemToEdit)
             {
             }

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

@@ -1,10 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
-using JetBrains.Annotations;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
@@ -42,10 +39,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerMatchSubScreen : MultiplayerTestScene
     {
-        private MultiplayerMatchSubScreen screen;
-
-        private BeatmapManager beatmaps;
-        private BeatmapSetInfo importedSet;
+        private MultiplayerMatchSubScreen screen = null!;
+        private BeatmapManager beatmaps = null!;
+        private BeatmapSetInfo importedSet = null!;
 
         public TestSceneMultiplayerMatchSubScreen()
             : base(false)
@@ -69,41 +65,25 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             AddStep("load match", () =>
             {
-                SelectedRoom.Value = new Room { Name = { Value = "Test Room" } };
-                LoadScreen(screen = new TestMultiplayerMatchSubScreen(SelectedRoom.Value));
+                SelectedRoom.Value = new Room { Name = "Test Room" };
+                LoadScreen(screen = new TestMultiplayerMatchSubScreen(SelectedRoom.Value!));
             });
 
             AddUntilStep("wait for load", () => screen.IsCurrentScreen());
         }
 
         [Test]
-        [FlakyTest]
-        /*
-         * Fail rate around 1.5%
-         *
-         * TearDown : System.AggregateException : One or more errors occurred. (Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index'))
-  ----> System.ArgumentOutOfRangeException : Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')
-         * --TearDown
-         *    at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
-         *   at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
-         *   at osu.Framework.Extensions.TaskExtensions.WaitSafely(Task task)
-         *   at osu.Framework.Testing.TestScene.checkForErrors()
-         *   at osu.Framework.Testing.TestScene.RunTestsFromNUnit()
-         *--ArgumentOutOfRangeException
-         *   at osu.Framework.Bindables.BindableList`1.removeAt(Int32 index, BindableList`1 caller)
-         *   at osu.Framework.Bindables.BindableList`1.removeAt(Int32 index, BindableList`1 caller)
-         *   at osu.Framework.Bindables.BindableList`1.removeAt(Int32 index, BindableList`1 caller)
-         *   at osu.Game.Online.Multiplayer.MultiplayerClient.<>c__DisplayClass106_0.<PlaylistItemChanged>b__0() in C:\BuildAgent\work\ecd860037212ac52\osu.Game\Online\Multiplayer\MultiplayerClient     .cs:line 702
-         *   at osu.Framework.Threading.ScheduledDelegate.RunTaskInternal()
-         */
         public void TestCreatedRoom()
         {
             AddStep("add playlist item", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID
-                });
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID
+                    }
+                ];
             });
 
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
@@ -112,16 +92,18 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestTaikoOnlyMod()
         {
             AddStep("add playlist item", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new TaikoRuleset().RulesetInfo).BeatmapInfo)
-                {
-                    RulesetID = new TaikoRuleset().RulesetInfo.OnlineID,
-                    AllowedMods = new[] { new APIMod(new TaikoModSwap()) }
-                });
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(new TestBeatmap(new TaikoRuleset().RulesetInfo).BeatmapInfo)
+                    {
+                        RulesetID = new TaikoRuleset().RulesetInfo.OnlineID,
+                        AllowedMods = new[] { new APIMod(new TaikoModSwap()) }
+                    }
+                ];
             });
 
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
@@ -133,32 +115,36 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestSettingValidity()
         {
             AddAssert("create button not enabled", () => !this.ChildrenOfType<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>().Single().Enabled.Value);
 
             AddStep("set playlist", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID
-                });
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID
+                    }
+                ];
             });
 
             AddAssert("create button enabled", () => this.ChildrenOfType<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>().Single().Enabled.Value);
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestStartMatchWhileSpectating()
         {
             AddStep("set playlist", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First()).BeatmapInfo)
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID
-                });
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First()).BeatmapInfo)
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID
+                    }
+                ];
             });
 
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
@@ -179,16 +165,18 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestFreeModSelectionHasAllowedMods()
         {
             AddStep("add playlist item with allowed mod", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
-                    AllowedMods = new[] { new APIMod(new OsuModDoubleTime()) }
-                });
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
+                        AllowedMods = new[] { new APIMod(new OsuModDoubleTime()) }
+                    }
+                ];
             });
 
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
@@ -206,16 +194,18 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestModSelectKeyWithAllowedMods()
         {
             AddStep("add playlist item with allowed mod", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
-                    AllowedMods = new[] { new APIMod(new OsuModDoubleTime()) }
-                });
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
+                        AllowedMods = new[] { new APIMod(new OsuModDoubleTime()) }
+                    }
+                ];
             });
 
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
@@ -228,15 +218,17 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestModSelectKeyWithNoAllowedMods()
         {
             AddStep("add playlist item with no allowed mods", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
-                });
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
+                    }
+                ];
             });
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
 
@@ -249,13 +241,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestNextPlaylistItemSelectedAfterCompletion()
         {
             AddStep("add two playlist items", () =>
             {
-                SelectedRoom.Value.Playlist.AddRange(new[]
-                {
+                SelectedRoom.Value!.Playlist =
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First()).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
@@ -264,7 +255,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                });
+                ];
             });
 
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
@@ -286,24 +277,26 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        [FlakyTest] // See above
         public void TestModSelectOverlay()
         {
             AddStep("add playlist item", () =>
             {
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
-                    RequiredMods = new[]
+                SelectedRoom.Value!.Playlist =
+                [
+                    new PlaylistItem(new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo)
                     {
-                        new APIMod(new OsuModDoubleTime { SpeedChange = { Value = 2.0 } }),
-                        new APIMod(new OsuModStrictTracking()),
-                    },
-                    AllowedMods = new[]
-                    {
-                        new APIMod(new OsuModFlashlight()),
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
+                        RequiredMods = new[]
+                        {
+                            new APIMod(new OsuModDoubleTime { SpeedChange = { Value = 2.0 } }),
+                            new APIMod(new OsuModStrictTracking()),
+                        },
+                        AllowedMods = new[]
+                        {
+                            new APIMod(new OsuModFlashlight()),
+                        }
                     }
-                });
+                ];
             });
             ClickButtonWhenEnabled<MultiplayerMatchSettingsOverlay.CreateOrUpdateButton>();
 
@@ -323,8 +316,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private partial class TestMultiplayerMatchSubScreen : MultiplayerMatchSubScreen
         {
             [Resolved(canBeNull: true)]
-            [CanBeNull]
-            private IDialogOverlay dialogOverlay { get; set; }
+            private IDialogOverlay? dialogOverlay { get; set; }
 
             public TestMultiplayerMatchSubScreen(Room room)
                 : base(room)

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -22,7 +20,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerPlayer : MultiplayerTestScene
     {
-        private MultiplayerPlayer player;
+        private MultiplayerPlayer player = null!;
 
         [Test]
         public void TestGameplay()
@@ -49,7 +47,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddUntilStep("score changed", () => player.GameplayState.ScoreProcessor.TotalScore.Value > 0);
         }
 
-        private void setup(Func<IReadOnlyList<Mod>> mods = null)
+        private void setup(Func<IReadOnlyList<Mod>>? mods = null)
         {
             AddStep("set beatmap", () =>
             {
@@ -64,10 +62,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("initialise gameplay", () =>
             {
-                Stack.Push(player = new MultiplayerPlayer(MultiplayerClient.ServerAPIRoom, new PlaylistItem(Beatmap.Value.BeatmapInfo)
+                Stack.Push(player = new MultiplayerPlayer(MultiplayerClient.ServerAPIRoom!, new PlaylistItem(Beatmap.Value.BeatmapInfo)
                 {
                     RulesetID = Beatmap.Value.BeatmapInfo.Ruleset.OnlineID,
-                }, MultiplayerClient.ServerRoom?.Users.ToArray()));
+                }, MultiplayerClient.ServerRoom!.Users.ToArray()));
             });
 
             AddUntilStep("wait for player to be current", () => player.IsCurrentScreen() && player.IsLoaded);

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

@@ -28,9 +28,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerPlaylist : MultiplayerTestScene
     {
-        [Cached(typeof(IBindable<PlaylistItem>))]
-        private readonly Bindable<PlaylistItem> currentItem = new Bindable<PlaylistItem>();
-
         private MultiplayerPlaylist list = null!;
         private BeatmapManager beatmaps = null!;
         private BeatmapSetInfo importedSet = null!;
@@ -51,12 +48,13 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("create list", () =>
             {
-                Child = list = new MultiplayerPlaylist
+                Child = list = new MultiplayerPlaylist(SelectedRoom.Value!)
                 {
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,
                     RelativeSizeAxes = Axes.Both,
-                    Size = new Vector2(0.4f, 0.8f)
+                    Size = new Vector2(0.4f, 0.8f),
+                    SelectedItem = new Bindable<PlaylistItem?>()
                 };
             });
 
@@ -166,9 +164,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 RoomManager.CreateRoom(new Room
                 {
-                    Name = { Value = "test name" },
+                    Name = "test name",
                     Playlist =
-                    {
+                    [
                         new PlaylistItem(new TestBeatmap(Ruleset.Value).BeatmapInfo)
                         {
                             RulesetID = Ruleset.Value.OnlineID
@@ -178,7 +176,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                             RulesetID = Ruleset.Value.OnlineID,
                             Expired = true
                         }
-                    }
+                    ]
                 });
             });
 

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using NUnit.Framework;
@@ -27,10 +25,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerQueueList : MultiplayerTestScene
     {
-        private MultiplayerQueueList playlist;
-        private BeatmapManager beatmaps;
-        private BeatmapSetInfo importedSet;
-        private BeatmapInfo importedBeatmap;
+        private MultiplayerQueueList playlist = null!;
+        private BeatmapManager beatmaps = null!;
+        private BeatmapSetInfo importedSet = null!;
+        private BeatmapInfo importedBeatmap = null!;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
@@ -46,12 +44,17 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("create playlist", () =>
             {
-                Child = playlist = new MultiplayerQueueList
+                Child = playlist = new MultiplayerQueueList(SelectedRoom.Value!)
                 {
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,
                     Size = new Vector2(500, 300),
-                    Items = { BindTarget = MultiplayerClient.ClientAPIRoom!.Playlist }
+                };
+
+                MultiplayerClient.ClientAPIRoom!.PropertyChanged += (_, e) =>
+                {
+                    if (e.PropertyName == nameof(Room.Playlist))
+                        playlist.Items.ReplaceRange(0, playlist.Items.Count, MultiplayerClient.ClientAPIRoom.Playlist);
                 };
             });
 
@@ -69,7 +72,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public void TestDeleteButtonAlwaysVisibleForHost()
         {
             AddStep("set all players queue mode", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { QueueMode = QueueMode.AllPlayers }).WaitSafely());
-            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode.Value == QueueMode.AllPlayers);
+            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode == QueueMode.AllPlayers);
 
             addPlaylistItem(() => API.LocalUser.Value.OnlineID);
             assertDeleteButtonVisibility(1, true);
@@ -81,7 +84,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public void TestDeleteButtonOnlyVisibleForItemOwnerIfNotHost()
         {
             AddStep("set all players queue mode", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { QueueMode = QueueMode.AllPlayers }).WaitSafely());
-            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode.Value == QueueMode.AllPlayers);
+            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode == QueueMode.AllPlayers);
 
             AddStep("join other user", () => MultiplayerClient.AddUser(new APIUser { Id = 1234 }));
             AddStep("set other user as host", () => MultiplayerClient.TransferHost(1234));
@@ -100,7 +103,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public void TestSingleItemDoesNotHaveDeleteButton()
         {
             AddStep("set all players queue mode", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { QueueMode = QueueMode.AllPlayers }).WaitSafely());
-            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode.Value == QueueMode.AllPlayers);
+            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode == QueueMode.AllPlayers);
 
             assertDeleteButtonVisibility(0, false);
         }
@@ -109,7 +112,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public void TestCurrentItemHasDeleteButtonIfNotSingle()
         {
             AddStep("set all players queue mode", () => MultiplayerClient.ChangeSettings(new MultiplayerRoomSettings { QueueMode = QueueMode.AllPlayers }).WaitSafely());
-            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode.Value == QueueMode.AllPlayers);
+            AddUntilStep("wait for queue mode change", () => MultiplayerClient.ClientAPIRoom?.QueueMode == QueueMode.AllPlayers);
 
             addPlaylistItem(() => API.LocalUser.Value.OnlineID);
 

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using NUnit.Framework;
 using osu.Game.Online.Rooms;
 using osu.Game.Rulesets.Osu;
@@ -16,7 +14,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestDisplayResults()
         {
-            MultiplayerResultsScreen screen = null;
+            MultiplayerResultsScreen screen = null!;
 
             AddStep("show results screen", () =>
             {

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

@@ -26,9 +26,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerSpectateButton : MultiplayerTestScene
     {
-        [Cached(typeof(IBindable<PlaylistItem>))]
-        private readonly Bindable<PlaylistItem> currentItem = new Bindable<PlaylistItem>();
-
         private MultiplayerSpectateButton spectateButton = null!;
         private MatchStartControl startControl = null!;
 
@@ -51,13 +48,13 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddStep("create button", () =>
             {
-                AvailabilityTracker.SelectedItem.BindTo(currentItem);
+                PlaylistItem item = SelectedRoom.Value!.Playlist.First();
+
+                AvailabilityTracker.SelectedItem.Value = item;
 
                 importedSet = beatmaps.GetAllUsableBeatmapSets().First();
                 Beatmap.Value = beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First());
 
-                currentItem.Value = SelectedRoom.Value.Playlist.First();
-
                 Child = new PopoverContainer
                 {
                     RelativeSizeAxes = Axes.Both,
@@ -72,12 +69,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
                                 Anchor = Anchor.Centre,
                                 Origin = Anchor.Centre,
                                 Size = new Vector2(200, 50),
+                                SelectedItem = new Bindable<PlaylistItem?>(item)
                             },
                             startControl = new MatchStartControl
                             {
                                 Anchor = Anchor.Centre,
                                 Origin = Anchor.Centre,
                                 Size = new Vector2(200, 50),
+                                SelectedItem = new Bindable<PlaylistItem?>(item)
                             }
                         }
                     }

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Graphics;
@@ -16,7 +14,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneMultiplayerSpectatorPlayerGrid : OsuManualInputManagerTestScene
     {
-        private PlayerGrid grid;
+        private PlayerGrid grid = null!;
 
         [SetUp]
         public void Setup() => Schedule(() =>

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Collections.Generic;
 using NUnit.Framework;
 using osu.Framework.Bindables;
@@ -32,7 +30,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [TestCase(1048576, 1048576)]
         public void TestDisplayTeamResults(int team1Score, int team2Score)
         {
-            MultiplayerResultsScreen screen = null;
+            MultiplayerResultsScreen screen = null!;
 
             AddStep("show results screen", () =>
             {

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -28,18 +26,18 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestScenePlaylistsRoomSettingsPlaylist : OnlinePlayTestScene
     {
-        private TestPlaylist playlist;
+        private TestPlaylist playlist = null!;
 
         [Test]
         public void TestItemRemovedOnDeletion()
         {
-            PlaylistItem selectedItem = null;
+            PlaylistItem selectedItem = null!;
 
             createPlaylist();
 
             moveToItem(0);
             AddStep("click", () => InputManager.Click(MouseButton.Left));
-            AddStep("retrieve selection", () => selectedItem = playlist.SelectedItem.Value);
+            AddStep("retrieve selection", () => selectedItem = playlist.SelectedItem.Value!);
 
             moveToDeleteButton(0);
             AddStep("click delete button", () => InputManager.Click(MouseButton.Left));
@@ -122,7 +120,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             InputManager.MoveMouseTo(item.ChildrenOfType<DrawableRoomPlaylistItem.PlaylistRemoveButton>().ElementAt(0), offset);
         });
 
-        private void createPlaylist(Action<TestPlaylist> setupPlaylist = null)
+        private void createPlaylist(Action<TestPlaylist>? setupPlaylist = null)
         {
             AddStep("create playlist", () =>
             {

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using NUnit.Framework;
@@ -27,9 +25,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestScenePlaylistsSongSelect : OnlinePlayTestScene
     {
-        private BeatmapManager manager;
-
-        private TestPlaylistsSongSelect songSelect;
+        private BeatmapManager manager = null!;
+        private TestPlaylistsSongSelect songSelect = null!;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
@@ -60,7 +57,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 SelectedMods.Value = Array.Empty<Mod>();
             });
 
-            AddStep("create song select", () => LoadScreen(songSelect = new TestPlaylistsSongSelect(SelectedRoom.Value)));
+            AddStep("create song select", () => LoadScreen(songSelect = new TestPlaylistsSongSelect(SelectedRoom.Value!)));
             AddUntilStep("wait for present", () => songSelect.IsCurrentScreen() && songSelect.BeatmapSetsLoaded);
         }
 
@@ -68,46 +65,41 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public void TestItemAddedIfEmptyOnStart()
         {
             AddStep("finalise selection", () => songSelect.FinaliseSelection());
-            AddAssert("playlist has 1 item", () => SelectedRoom.Value.Playlist.Count == 1);
+            AddAssert("playlist has 1 item", () => SelectedRoom.Value!.Playlist.Count == 1);
         }
 
         [Test]
         public void TestItemAddedWhenCreateNewItemClicked()
         {
-            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
-            AddAssert("playlist has 1 item", () => SelectedRoom.Value.Playlist.Count == 1);
+            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem!());
+            AddAssert("playlist has 1 item", () => SelectedRoom.Value!.Playlist.Count == 1);
         }
 
         [Test]
         public void TestItemNotAddedIfExistingOnStart()
         {
-            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
+            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem!());
             AddStep("finalise selection", () => songSelect.FinaliseSelection());
-            AddAssert("playlist has 1 item", () => SelectedRoom.Value.Playlist.Count == 1);
+            AddAssert("playlist has 1 item", () => SelectedRoom.Value!.Playlist.Count == 1);
         }
 
         [Test]
         public void TestAddSameItemMultipleTimes()
         {
-            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
-            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
-            AddAssert("playlist has 2 items", () => SelectedRoom.Value.Playlist.Count == 2);
+            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem!());
+            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem!());
+            AddAssert("playlist has 2 items", () => SelectedRoom.Value!.Playlist.Count == 2);
         }
 
         [Test]
         public void TestAddItemAfterRearrangement()
         {
-            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
-            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
-            AddStep("rearrange", () =>
-            {
-                var item = SelectedRoom.Value.Playlist[0];
-                SelectedRoom.Value.Playlist.RemoveAt(0);
-                SelectedRoom.Value.Playlist.Add(item);
-            });
+            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem!());
+            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem!());
+            AddStep("rearrange", () => SelectedRoom.Value!.Playlist = SelectedRoom.Value!.Playlist.Skip(1).Append(SelectedRoom.Value!.Playlist[0]).ToArray());
 
-            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
-            AddAssert("new item has id 2", () => SelectedRoom.Value.Playlist.Last().ID == 2);
+            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem!());
+            AddAssert("new item has id 2", () => SelectedRoom.Value!.Playlist.Last().ID == 2);
         }
 
         /// <summary>
@@ -117,19 +109,19 @@ namespace osu.Game.Tests.Visual.Multiplayer
         public void TestNewItemHasNewModInstances()
         {
             AddStep("set dt mod", () => SelectedMods.Value = new[] { new OsuModDoubleTime() });
-            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem());
+            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem!());
             AddStep("change mod rate", () => ((OsuModDoubleTime)SelectedMods.Value[0]).SpeedChange.Value = 2);
-            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem());
+            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem!());
 
             AddAssert("item 1 has rate 1.5", () =>
             {
-                var mod = (OsuModDoubleTime)SelectedRoom.Value.Playlist.First().RequiredMods[0].ToMod(new OsuRuleset());
+                var mod = (OsuModDoubleTime)SelectedRoom.Value!.Playlist.First().RequiredMods[0].ToMod(new OsuRuleset());
                 return Precision.AlmostEquals(1.5, mod.SpeedChange.Value);
             });
 
             AddAssert("item 2 has rate 2", () =>
             {
-                var mod = (OsuModDoubleTime)SelectedRoom.Value.Playlist.Last().RequiredMods[0].ToMod(new OsuRuleset());
+                var mod = (OsuModDoubleTime)SelectedRoom.Value!.Playlist.Last().RequiredMods[0].ToMod(new OsuRuleset());
                 return Precision.AlmostEquals(2, mod.SpeedChange.Value);
             });
         }
@@ -140,7 +132,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestGlobalModInstancesNotRetained()
         {
-            OsuModDoubleTime mod = null;
+            OsuModDoubleTime mod = null!;
 
             AddStep("set dt mod and store", () =>
             {
@@ -150,12 +142,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 mod = (OsuModDoubleTime)SelectedMods.Value[0];
             });
 
-            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem());
+            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem!());
 
             AddStep("change stored mod rate", () => mod.SpeedChange.Value = 2);
             AddAssert("item has rate 1.5", () =>
             {
-                var m = (OsuModDoubleTime)SelectedRoom.Value.Playlist.First().RequiredMods[0].ToMod(new OsuRuleset());
+                var m = (OsuModDoubleTime)SelectedRoom.Value!.Playlist.First().RequiredMods[0].ToMod(new OsuRuleset());
                 return Precision.AlmostEquals(1.5, m.SpeedChange.Value);
             });
         }

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

@@ -9,7 +9,6 @@ using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Online.API.Requests.Responses;
 using osu.Game.Online.Multiplayer;
-using osu.Game.Online.Rooms;
 using osu.Game.Screens.OnlinePlay.Lounge.Components;
 
 namespace osu.Game.Tests.Visual.Multiplayer
@@ -18,10 +17,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
     {
         private readonly Mock<MultiplayerClient> multiplayerClient = new Mock<MultiplayerClient>();
 
-        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent) =>
-            // not used directly in component, but required due to it inheriting from OnlinePlayComposite.
-            new CachedModelDependencyContainer<Room>(base.CreateChildDependencies(parent));
-
         [BackgroundDependencyLoader]
         private void load()
         {

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

@@ -20,7 +20,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             {
                 SelectedRoom.Value = new Room();
 
-                Child = new StarRatingRangeDisplay
+                Child = new StarRatingRangeDisplay(SelectedRoom.Value)
                 {
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre
@@ -33,11 +33,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             AddStep("set playlist", () =>
             {
-                SelectedRoom.Value.Playlist.AddRange(new[]
-                {
+                SelectedRoom.Value!.Playlist =
+                [
                     new PlaylistItem(new BeatmapInfo { StarRating = min }),
                     new PlaylistItem(new BeatmapInfo { StarRating = max }),
-                });
+                ];
             });
         }
     }

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

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using NUnit.Framework;
@@ -29,10 +27,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
 {
     public partial class TestSceneTeamVersus : ScreenTestScene
     {
-        private BeatmapManager beatmaps;
-        private BeatmapSetInfo importedSet;
+        private BeatmapManager beatmaps = null!;
+        private BeatmapSetInfo importedSet = null!;
 
-        private TestMultiplayerComponents multiplayerComponents;
+        private TestMultiplayerComponents multiplayerComponents = null!;
 
         private TestMultiplayerClient multiplayerClient => multiplayerComponents.MultiplayerClient;
 
@@ -64,15 +62,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                Type = { Value = MatchType.TeamVersus },
+                Name = "Test Room",
+                Type = MatchType.TeamVersus,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddUntilStep("room type is team vs", () => multiplayerClient.ClientRoom?.Settings.MatchType == MatchType.TeamVersus);
@@ -84,15 +82,15 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                Type = { Value = MatchType.TeamVersus },
+                Name = "Test Room",
+                Type = MatchType.TeamVersus,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                }
+                ]
             });
 
             AddUntilStep("user on team 0", () => (multiplayerClient.ClientRoom?.Users.FirstOrDefault()?.MatchState as TeamVersusUserState)?.TeamID == 0);
@@ -121,25 +119,25 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
-                Type = { Value = MatchType.HeadToHead },
+                Name = "Test Room",
+                Type = MatchType.HeadToHead,
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
-            AddUntilStep("match type head to head", () => multiplayerClient.ClientAPIRoom?.Type.Value == MatchType.HeadToHead);
+            AddUntilStep("match type head to head", () => multiplayerClient.ClientAPIRoom?.Type == MatchType.HeadToHead);
 
             AddStep("change match type", () => multiplayerClient.ChangeSettings(new MultiplayerRoomSettings
             {
                 MatchType = MatchType.TeamVersus
             }).WaitSafely());
 
-            AddUntilStep("api room updated to team versus", () => multiplayerClient.ClientAPIRoom?.Type.Value == MatchType.TeamVersus);
+            AddUntilStep("api room updated to team versus", () => multiplayerClient.ClientAPIRoom?.Type == MatchType.TeamVersus);
         }
 
         [Test]
@@ -147,14 +145,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             createRoom(() => new Room
             {
-                Name = { Value = "Test Room" },
+                Name = "Test Room",
                 Playlist =
-                {
+                [
                     new PlaylistItem(beatmaps.GetWorkingBeatmap(importedSet.Beatmaps.First(b => b.Ruleset.OnlineID == 0)).BeatmapInfo)
                     {
                         RulesetID = new OsuRuleset().RulesetInfo.OnlineID,
                     }
-                }
+                ]
             });
 
             AddUntilStep("room type is head to head", () => multiplayerClient.ClientRoom?.Settings.MatchType == MatchType.HeadToHead);

osu.Game.Tests/Visual/Online/TestSceneReplayMissingBeatmap.cs

@@ -40,15 +40,13 @@ namespace osu.Game.Tests.Visual.Online
 
             AddStep("import score", () =>
             {
-                using (var resourceStream = TestResources.OpenResource("Replays/mania-replay.osr"))
-                {
-                    var importTask = new ImportTask(resourceStream, "replay.osr");
+                var resourceStream = TestResources.OpenResource("Replays/mania-replay.osr");
+                var importTask = new ImportTask(resourceStream, "replay.osr");
 
-                    Game.ScoreManager.Import(new[] { importTask });
-                }
+                Game.ScoreManager.Import(new[] { importTask });
             });
 
-            AddUntilStep("Replay missing notification show", () => Game.Notifications.ChildrenOfType<MissingBeatmapNotification>().Any());
+            AddUntilStep("Replay missing notification shown", () => Game.Notifications.ChildrenOfType<MissingBeatmapNotification>().Any());
         }
 
         [Test]
@@ -58,15 +56,13 @@ namespace osu.Game.Tests.Visual.Online
 
             AddStep("import score", () =>
             {
-                using (var resourceStream = TestResources.OpenResource("Replays/mania-replay.osr"))
-                {
-                    var importTask = new ImportTask(resourceStream, "replay.osr");
+                var resourceStream = TestResources.OpenResource("Replays/mania-replay.osr");
+                var importTask = new ImportTask(resourceStream, "replay.osr");
 
-                    Game.ScoreManager.Import(new[] { importTask });
-                }
+                Game.ScoreManager.Import(new[] { importTask });
             });
 
-            AddUntilStep("Replay missing notification not show", () => !Game.Notifications.ChildrenOfType<MissingBeatmapNotification>().Any());
+            AddUntilStep("Replay missing notification not shown", () => !Game.Notifications.ChildrenOfType<MissingBeatmapNotification>().Any());
         }
 
         private void setupBeatmapResponse(APIBeatmap b)

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsLoungeSubScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Bindables;
@@ -21,7 +19,7 @@ namespace osu.Game.Tests.Visual.Playlists
     {
         protected new TestRoomManager RoomManager => (TestRoomManager)base.RoomManager;
 
-        private TestLoungeSubScreen loungeScreen;
+        private TestLoungeSubScreen loungeScreen = null!;
 
         public override void SetUpSteps()
         {
@@ -97,7 +95,7 @@ namespace osu.Game.Tests.Visual.Playlists
 
         private partial class TestLoungeSubScreen : PlaylistsLoungeSubScreen
         {
-            public new Bindable<Room> SelectedRoom => base.SelectedRoom;
+            public new Bindable<Room?> SelectedRoom => base.SelectedRoom;
         }
     }
 }

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsMatchSettingsOverlay.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using NUnit.Framework;
 using osu.Framework.Bindables;
@@ -22,7 +20,7 @@ namespace osu.Game.Tests.Visual.Playlists
     {
         protected new TestRoomManager RoomManager => (TestRoomManager)base.RoomManager;
 
-        private TestRoomSettings settings;
+        private TestRoomSettings settings = null!;
 
         protected override OnlinePlayTestSceneDependencies CreateOnlinePlayDependencies() => new TestDependencies();
 
@@ -34,7 +32,7 @@ namespace osu.Game.Tests.Visual.Playlists
             {
                 SelectedRoom.Value = new Room();
 
-                Child = settings = new TestRoomSettings(SelectedRoom.Value)
+                Child = settings = new TestRoomSettings(SelectedRoom.Value!)
                 {
                     RelativeSizeAxes = Axes.Both,
                     State = { Value = Visibility.Visible }
@@ -47,19 +45,19 @@ namespace osu.Game.Tests.Visual.Playlists
         {
             AddStep("clear name and beatmap", () =>
             {
-                SelectedRoom.Value.Name.Value = "";
-                SelectedRoom.Value.Playlist.Clear();
+                SelectedRoom.Value!.Name = "";
+                SelectedRoom.Value!.Playlist = [];
             });
 
             AddAssert("button disabled", () => !settings.ApplyButton.Enabled.Value);
 
-            AddStep("set name", () => SelectedRoom.Value.Name.Value = "Room name");
+            AddStep("set name", () => SelectedRoom.Value!.Name = "Room name");
             AddAssert("button disabled", () => !settings.ApplyButton.Enabled.Value);
 
-            AddStep("set beatmap", () => SelectedRoom.Value.Playlist.Add(new PlaylistItem(CreateBeatmap(Ruleset.Value).BeatmapInfo)));
+            AddStep("set beatmap", () => SelectedRoom.Value!.Playlist = [new PlaylistItem(CreateBeatmap(Ruleset.Value).BeatmapInfo)]);
             AddAssert("button enabled", () => settings.ApplyButton.Enabled.Value);
 
-            AddStep("clear name", () => SelectedRoom.Value.Name.Value = "");
+            AddStep("clear name", () => SelectedRoom.Value!.Name = "");
             AddAssert("button disabled", () => !settings.ApplyButton.Enabled.Value);
         }
 
@@ -69,13 +67,13 @@ namespace osu.Game.Tests.Visual.Playlists
             const string expected_name = "expected name";
             TimeSpan expectedDuration = TimeSpan.FromMinutes(15);
 
-            Room createdRoom = null;
+            Room createdRoom = null!;
 
             AddStep("setup", () =>
             {
                 settings.NameField.Current.Value = expected_name;
                 settings.DurationField.Current.Value = expectedDuration;
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(CreateBeatmap(Ruleset.Value).BeatmapInfo));
+                SelectedRoom.Value!.Playlist = [new PlaylistItem(CreateBeatmap(Ruleset.Value).BeatmapInfo)];
 
                 RoomManager.CreateRequested = r =>
                 {
@@ -85,8 +83,8 @@ namespace osu.Game.Tests.Visual.Playlists
             });
 
             AddStep("create room", () => settings.ApplyButton.Action.Invoke());
-            AddAssert("has correct name", () => createdRoom.Name.Value == expected_name);
-            AddAssert("has correct duration", () => createdRoom.Duration.Value == expectedDuration);
+            AddAssert("has correct name", () => createdRoom.Name == expected_name);
+            AddAssert("has correct duration", () => createdRoom.Duration == expectedDuration);
         }
 
         [Test]
@@ -94,14 +92,14 @@ namespace osu.Game.Tests.Visual.Playlists
         {
             const string not_found_prefix = "beatmaps not found:";
 
-            string errorMessage = null;
+            string errorMessage = null!;
 
             AddStep("setup", () =>
             {
                 var beatmap = CreateBeatmap(Ruleset.Value).BeatmapInfo;
 
-                SelectedRoom.Value.Name.Value = "Test Room";
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(beatmap));
+                SelectedRoom.Value!.Name = "Test Room";
+                SelectedRoom.Value!.Playlist = [new PlaylistItem(beatmap)];
 
                 errorMessage = $"{not_found_prefix} {beatmap.OnlineID}";
 
@@ -109,13 +107,13 @@ namespace osu.Game.Tests.Visual.Playlists
             });
 
             AddAssert("error not displayed", () => !settings.ErrorText.IsPresent);
-            AddAssert("playlist item valid", () => SelectedRoom.Value.Playlist[0].Valid.Value);
+            AddAssert("playlist item valid", () => SelectedRoom.Value!.Playlist[0].Valid.Value);
 
             AddStep("create room", () => settings.ApplyButton.Action.Invoke());
 
             AddAssert("error displayed", () => settings.ErrorText.IsPresent);
             AddAssert("error has custom text", () => settings.ErrorText.Text != errorMessage);
-            AddAssert("playlist item marked invalid", () => !SelectedRoom.Value.Playlist[0].Valid.Value);
+            AddAssert("playlist item marked invalid", () => !SelectedRoom.Value!.Playlist[0].Valid.Value);
         }
 
         [Test]
@@ -127,8 +125,8 @@ namespace osu.Game.Tests.Visual.Playlists
 
             AddStep("setup", () =>
             {
-                SelectedRoom.Value.Name.Value = "Test Room";
-                SelectedRoom.Value.Playlist.Add(new PlaylistItem(CreateBeatmap(Ruleset.Value).BeatmapInfo));
+                SelectedRoom.Value!.Name = "Test Room";
+                SelectedRoom.Value!.Playlist = [new PlaylistItem(CreateBeatmap(Ruleset.Value).BeatmapInfo)];
 
                 RoomManager.CreateRequested = _ => failText;
             });
@@ -169,7 +167,7 @@ namespace osu.Game.Tests.Visual.Playlists
 
         protected class TestRoomManager : IRoomManager
         {
-            public Func<Room, string> CreateRequested;
+            public Func<Room, string>? CreateRequested;
 
             public event Action RoomsUpdated
             {
@@ -187,7 +185,7 @@ namespace osu.Game.Tests.Visual.Playlists
 
             public void ClearRooms() => throw new NotImplementedException();
 
-            public void CreateRoom(Room room, Action<Room> onSuccess = null, Action<string> onError = null)
+            public void CreateRoom(Room room, Action<Room>? onSuccess = null, Action<string>? onError = null)
             {
                 if (CreateRequested == null)
                     return;
@@ -200,7 +198,7 @@ namespace osu.Game.Tests.Visual.Playlists
                     onSuccess?.Invoke(room);
             }
 
-            public void JoinRoom(Room room, string password, Action<Room> onSuccess = null, Action<string> onError = null) => throw new NotImplementedException();
+            public void JoinRoom(Room room, string? password, Action<Room>? onSuccess = null, Action<string>? onError = null) => throw new NotImplementedException();
 
             public void PartRoom() => throw new NotImplementedException();
         }

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsParticipantsList.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Graphics;
 using osu.Game.Online.API.Requests.Responses;
@@ -19,17 +20,16 @@ namespace osu.Game.Tests.Visual.Playlists
 
             AddStep("create list", () =>
             {
-                SelectedRoom.Value = new Room { RoomID = { Value = 7 } };
-
-                for (int i = 0; i < 50; i++)
+                SelectedRoom.Value = new Room
                 {
-                    SelectedRoom.Value.RecentParticipants.Add(new APIUser
+                    RoomID = 7,
+                    RecentParticipants = Enumerable.Range(0, 50).Select(_ => new APIUser
                     {
                         Username = "peppy",
                         Statistics = new UserStatistics { GlobalRank = 1234 },
                         Id = 2
-                    });
-                }
+                    }).ToArray()
+                };
             });
         }
 
@@ -38,7 +38,7 @@ namespace osu.Game.Tests.Visual.Playlists
         {
             AddStep("create component", () =>
             {
-                Child = new ParticipantsDisplay(Direction.Horizontal)
+                Child = new ParticipantsDisplay(SelectedRoom.Value!, Direction.Horizontal)
                 {
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,
@@ -52,7 +52,7 @@ namespace osu.Game.Tests.Visual.Playlists
         {
             AddStep("create component", () =>
             {
-                Child = new ParticipantsDisplay(Direction.Vertical)
+                Child = new ParticipantsDisplay(SelectedRoom.Value!, Direction.Vertical)
                 {
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsResultsScreen.cs

@@ -1,13 +1,10 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
-using JetBrains.Annotations;
 using Newtonsoft.Json.Linq;
 using NUnit.Framework;
 using osu.Framework.Graphics.Containers;
@@ -34,14 +31,14 @@ namespace osu.Game.Tests.Visual.Playlists
         private const int scores_per_result = 10;
         private const int real_user_position = 200;
 
-        private TestResultsScreen resultsScreen;
+        private TestResultsScreen resultsScreen = null!;
 
         private int lowestScoreId; // Score ID of the lowest score in the list.
         private int highestScoreId; // Score ID of the highest score in the list.
 
         private bool requestComplete;
         private int totalCount;
-        private ScoreInfo userScore;
+        private ScoreInfo userScore = null!;
 
         [SetUpSteps]
         public override void SetUpSteps()
@@ -205,7 +202,7 @@ namespace osu.Game.Tests.Visual.Playlists
             AddAssert("placeholder shown", () => this.ChildrenOfType<MessagePlaceholder>().Count(), () => Is.EqualTo(1));
         }
 
-        private void createResults(Func<ScoreInfo> getScore = null)
+        private void createResults(Func<ScoreInfo>? getScore = null)
         {
             AddStep("load results", () =>
             {
@@ -229,7 +226,7 @@ namespace osu.Game.Tests.Visual.Playlists
             AddWaitStep("wait for display", 5);
         }
 
-        private void bindHandler(bool delayed = false, ScoreInfo userScore = null, bool failRequests = false, bool noScores = false) => ((DummyAPIAccess)API).HandleRequest = request =>
+        private void bindHandler(bool delayed = false, ScoreInfo? userScore = null, bool failRequests = false, bool noScores = false) => ((DummyAPIAccess)API).HandleRequest = request =>
         {
             // pre-check for requests we should be handling (as they are scheduled below).
             switch (request)
@@ -286,7 +283,7 @@ namespace osu.Game.Tests.Visual.Playlists
             req.TriggerFailure(new WebException("Failed."));
         }
 
-        private MultiplayerScore createUserResponse([NotNull] ScoreInfo userScore)
+        private MultiplayerScore createUserResponse(ScoreInfo userScore)
         {
             var multiplayerUserScore = new MultiplayerScore
             {
@@ -420,7 +417,7 @@ namespace osu.Game.Tests.Visual.Playlists
             public new LoadingSpinner RightSpinner => base.RightSpinner;
             public new ScorePanelList ScorePanelList => base.ScorePanelList;
 
-            public TestResultsScreen([CanBeNull] ScoreInfo score, int roomId, PlaylistItem playlistItem)
+            public TestResultsScreen(ScoreInfo? score, int roomId, PlaylistItem playlistItem)
                 : base(score, roomId, playlistItem)
             {
                 AllowRetry = true;

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsRoomCreation.cs

@@ -1,12 +1,9 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Diagnostics;
 using System.Linq;
-using JetBrains.Annotations;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
@@ -35,11 +32,9 @@ namespace osu.Game.Tests.Visual.Playlists
 {
     public partial class TestScenePlaylistsRoomCreation : OnlinePlayTestScene
     {
-        private BeatmapManager manager;
-
-        private TestPlaylistsRoomSubScreen match;
-
-        private BeatmapSetInfo importedBeatmap;
+        private BeatmapManager manager = null!;
+        private TestPlaylistsRoomSubScreen match = null!;
+        private BeatmapSetInfo importedBeatmap = null!;
 
         [BackgroundDependencyLoader]
         private void load(GameHost host, AudioManager audio)
@@ -52,11 +47,11 @@ namespace osu.Game.Tests.Visual.Playlists
         [SetUpSteps]
         public void SetupSteps()
         {
-            AddStep("set room", () => SelectedRoom!.Value = new Room());
+            AddStep("set room", () => SelectedRoom.Value = new Room());
 
             importBeatmap();
 
-            AddStep("load match", () => LoadScreen(match = new TestPlaylistsRoomSubScreen(SelectedRoom!.Value)));
+            AddStep("load match", () => LoadScreen(match = new TestPlaylistsRoomSubScreen(SelectedRoom.Value!)));
             AddUntilStep("wait for load", () => match.IsCurrentScreen());
         }
 
@@ -65,14 +60,17 @@ namespace osu.Game.Tests.Visual.Playlists
         {
             setupAndCreateRoom(room =>
             {
-                room.Name.Value = "my awesome room";
-                room.Host.Value = API.LocalUser.Value;
-                room.RecentParticipants.Add(room.Host.Value);
-                room.EndDate.Value = DateTimeOffset.Now.AddMinutes(5);
-                room.Playlist.Add(new PlaylistItem(importedBeatmap.Beatmaps.First())
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID
-                });
+                room.Name = "my awesome room";
+                room.Host = API.LocalUser.Value;
+                room.RecentParticipants = [room.Host];
+                room.EndDate = DateTimeOffset.Now.AddMinutes(5);
+                room.Playlist =
+                [
+                    new PlaylistItem(importedBeatmap.Beatmaps.First())
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID
+                    }
+                ];
             });
 
             AddUntilStep("Progress details are hidden", () => match.ChildrenOfType<RoomLocalUserInfo>().FirstOrDefault()?.Parent!.Alpha == 0);
@@ -88,15 +86,18 @@ namespace osu.Game.Tests.Visual.Playlists
         {
             setupAndCreateRoom(room =>
             {
-                room.Name.Value = "my awesome room";
-                room.MaxAttempts.Value = 5;
-                room.Host.Value = API.LocalUser.Value;
-                room.RecentParticipants.Add(room.Host.Value);
-                room.EndDate.Value = DateTimeOffset.Now.AddMinutes(5);
-                room.Playlist.Add(new PlaylistItem(importedBeatmap.Beatmaps.First())
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID
-                });
+                room.Name = "my awesome room";
+                room.MaxAttempts = 5;
+                room.Host = API.LocalUser.Value;
+                room.RecentParticipants = [room.Host];
+                room.EndDate = DateTimeOffset.Now.AddMinutes(5);
+                room.Playlist =
+                [
+                    new PlaylistItem(importedBeatmap.Beatmaps.First())
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID
+                    }
+                ];
             });
 
             AddUntilStep("Progress details are visible", () => match.ChildrenOfType<RoomLocalUserInfo>().FirstOrDefault()?.Parent!.Alpha == 1);
@@ -107,21 +108,24 @@ namespace osu.Game.Tests.Visual.Playlists
         {
             setupAndCreateRoom(room =>
             {
-                room.Name.Value = "my awesome room";
-                room.Host.Value = API.LocalUser.Value;
-                room.Playlist.Add(new PlaylistItem(importedBeatmap.Beatmaps.First())
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID
-                });
+                room.Name = "my awesome room";
+                room.Host = API.LocalUser.Value;
+                room.Playlist =
+                [
+                    new PlaylistItem(importedBeatmap.Beatmaps.First())
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID
+                    }
+                ];
             });
 
-            AddAssert("first playlist item selected", () => match.SelectedItem.Value == SelectedRoom!.Value.Playlist[0]);
+            AddAssert("first playlist item selected", () => match.SelectedItem.Value == SelectedRoom.Value!.Playlist[0]);
         }
 
         [Test]
         public void TestBeatmapUpdatedOnReImport()
         {
-            string realHash = null;
+            string realHash = null!;
             int realOnlineId = 0;
             int realOnlineSetId = 0;
 
@@ -139,40 +143,40 @@ namespace osu.Game.Tests.Visual.Playlists
                     BeatmapInfo =
                     {
                         OnlineID = realOnlineId,
-                        Metadata = new BeatmapMetadata(),
-                        BeatmapSet =
-                        {
-                            OnlineID = realOnlineSetId
-                        }
+                        Metadata = new BeatmapMetadata()
                     },
                 };
 
+                Debug.Assert(modifiedBeatmap.BeatmapInfo.BeatmapSet != null);
+                modifiedBeatmap.BeatmapInfo.BeatmapSet!.OnlineID = realOnlineSetId;
+
                 modifiedBeatmap.HitObjects.Clear();
                 modifiedBeatmap.HitObjects.Add(new HitCircle { StartTime = 5000 });
 
-                Debug.Assert(modifiedBeatmap.BeatmapInfo.BeatmapSet != null);
-
                 manager.Import(modifiedBeatmap.BeatmapInfo.BeatmapSet);
             });
 
             // Create the room using the real beatmap values.
             setupAndCreateRoom(room =>
             {
-                room.Name.Value = "my awesome room";
-                room.Host.Value = API.LocalUser.Value;
-                room.Playlist.Add(new PlaylistItem(new BeatmapInfo
-                {
-                    MD5Hash = realHash,
-                    OnlineID = realOnlineId,
-                    Metadata = new BeatmapMetadata(),
-                    BeatmapSet = new BeatmapSetInfo
+                room.Name = "my awesome room";
+                room.Host = API.LocalUser.Value;
+                room.Playlist =
+                [
+                    new PlaylistItem(new BeatmapInfo
                     {
-                        OnlineID = realOnlineSetId,
+                        MD5Hash = realHash,
+                        OnlineID = realOnlineId,
+                        Metadata = new BeatmapMetadata(),
+                        BeatmapSet = new BeatmapSetInfo
+                        {
+                            OnlineID = realOnlineSetId,
+                        }
+                    })
+                    {
+                        RulesetID = new OsuRuleset().RulesetInfo.OnlineID
                     }
-                })
-                {
-                    RulesetID = new OsuRuleset().RulesetInfo.OnlineID
-                });
+                ];
             });
 
             AddAssert("match has default beatmap", () => match.Beatmap.IsDefault);
@@ -181,17 +185,11 @@ namespace osu.Game.Tests.Visual.Playlists
             {
                 var originalBeatmap = new TestBeatmap(new OsuRuleset().RulesetInfo)
                 {
-                    BeatmapInfo =
-                    {
-                        OnlineID = realOnlineId,
-                        BeatmapSet =
-                        {
-                            OnlineID = realOnlineSetId
-                        }
-                    },
+                    BeatmapInfo = { OnlineID = realOnlineId },
                 };
 
                 Debug.Assert(originalBeatmap.BeatmapInfo.BeatmapSet != null);
+                originalBeatmap.BeatmapInfo.BeatmapSet.OnlineID = realOnlineSetId;
 
                 manager.Import(originalBeatmap.BeatmapInfo.BeatmapSet);
             });
@@ -201,7 +199,7 @@ namespace osu.Game.Tests.Visual.Playlists
 
         private void setupAndCreateRoom(Action<Room> room)
         {
-            AddStep("setup room", () => room(SelectedRoom!.Value));
+            AddStep("setup room", () => room(SelectedRoom.Value!));
 
             AddStep("click create button", () =>
             {
@@ -215,19 +213,17 @@ namespace osu.Game.Tests.Visual.Playlists
             var beatmap = CreateBeatmap(new OsuRuleset().RulesetInfo);
 
             Debug.Assert(beatmap.BeatmapInfo.BeatmapSet != null);
-
-            importedBeatmap = manager.Import(beatmap.BeatmapInfo.BeatmapSet)?.Value.Detach();
+            importedBeatmap = manager.Import(beatmap.BeatmapInfo.BeatmapSet)!.Value.Detach();
         });
 
         private partial class TestPlaylistsRoomSubScreen : PlaylistsRoomSubScreen
         {
-            public new Bindable<PlaylistItem> SelectedItem => base.SelectedItem;
+            public new Bindable<PlaylistItem?> SelectedItem => base.SelectedItem;
 
             public new Bindable<WorkingBeatmap> Beatmap => base.Beatmap;
 
             [Resolved(canBeNull: true)]
-            [CanBeNull]
-            private IDialogOverlay dialogOverlay { get; set; }
+            private IDialogOverlay? dialogOverlay { get; set; }
 
             public TestPlaylistsRoomSubScreen(Room room)
                 : base(room)

osu.Game.Tests/Visual/Playlists/TestScenePlaylistsRoomSubScreen.cs

@@ -0,0 +1,41 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using NUnit.Framework;
+using osu.Framework.Screens;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Online.Rooms;
+using osu.Game.Online.Rooms.RoomStatuses;
+using osu.Game.Screens.OnlinePlay.Playlists;
+using osu.Game.Tests.Visual.OnlinePlay;
+
+namespace osu.Game.Tests.Visual.Playlists
+{
+    public partial class TestScenePlaylistsRoomSubScreen : OnlinePlayTestScene
+    {
+        protected new TestRoomManager RoomManager => (TestRoomManager)base.RoomManager;
+
+        [Test]
+        public void TestStatusUpdateOnEnter()
+        {
+            Room room = null!;
+            PlaylistsRoomSubScreen roomScreen = null!;
+
+            AddStep("create room", () =>
+            {
+                RoomManager.AddRoom(room = new Room
+                {
+                    Name = @"Test Room",
+                    Host = new APIUser { Username = @"Host" },
+                    Category = RoomCategory.Normal,
+                    EndDate = DateTimeOffset.Now.AddMinutes(-1)
+                });
+            });
+
+            AddStep("push screen", () => LoadScreen(roomScreen = new PlaylistsRoomSubScreen(room)));
+            AddUntilStep("wait for screen load", () => roomScreen.IsCurrentScreen());
+            AddAssert("status is still ended", () => roomScreen.Room.Status, Is.TypeOf<RoomStatusEnded>);
+        }
+    }
+}

osu.Game.Tests/Visual/UserInterface/TestSceneBeatmapAttributeText.cs

@@ -73,10 +73,10 @@ namespace osu.Game.Tests.Visual.UserInterface
             });
         });
 
-        [TestCase(BeatmapAttribute.CircleSize, "Circle Size: 1.00")]
-        [TestCase(BeatmapAttribute.HPDrain, "HP Drain: 2.00")]
-        [TestCase(BeatmapAttribute.Accuracy, "Accuracy: 3.00")]
-        [TestCase(BeatmapAttribute.ApproachRate, "Approach Rate: 4.00")]
+        [TestCase(BeatmapAttribute.CircleSize, "Circle Size: 1")]
+        [TestCase(BeatmapAttribute.HPDrain, "HP Drain: 2")]
+        [TestCase(BeatmapAttribute.Accuracy, "Accuracy: 3")]
+        [TestCase(BeatmapAttribute.ApproachRate, "Approach Rate: 4")]
         [TestCase(BeatmapAttribute.Title, "Title: _Title")]
         [TestCase(BeatmapAttribute.Artist, "Artist: _Artist")]
         [TestCase(BeatmapAttribute.Creator, "Creator: _Creator")]
@@ -121,15 +121,15 @@ namespace osu.Game.Tests.Visual.UserInterface
                     Difficulty =
                     {
                         ApproachRate = 10,
-                        CircleSize = 9
+                        CircleSize = 9.5f
                     }
                 }
             }));
 
-            test(BeatmapAttribute.BPM, new OsuModDoubleTime(), "BPM: 100.00", "BPM: 150.00");
+            test(BeatmapAttribute.BPM, new OsuModDoubleTime(), "BPM: 100", "BPM: 150");
             test(BeatmapAttribute.Length, new OsuModDoubleTime(), "Length: 00:30", "Length: 00:20");
-            test(BeatmapAttribute.ApproachRate, new OsuModDoubleTime(), "Approach Rate: 10.00", "Approach Rate: 11.00");
-            test(BeatmapAttribute.CircleSize, new OsuModHardRock(), "Circle Size: 9.00", "Circle Size: 10.00");
+            test(BeatmapAttribute.ApproachRate, new OsuModDoubleTime(), "Approach Rate: 10", "Approach Rate: 11");
+            test(BeatmapAttribute.CircleSize, new OsuModHardRock(), "Circle Size: 9.5", "Circle Size: 10");
 
             void test(BeatmapAttribute attribute, Mod mod, string before, string after)
             {

osu.Game.Tests/Visual/UserInterface/TestSceneMainMenuButton.cs

@@ -53,13 +53,13 @@ namespace osu.Game.Tests.Visual.UserInterface
                         beatmap.OnlineID = 1001;
                         getRoomRequest.TriggerSuccess(new Room
                         {
-                            RoomID = { Value = 1234 },
+                            RoomID = 1234,
                             Playlist =
-                            {
+                            [
                                 new PlaylistItem(beatmap)
-                            },
-                            StartDate = { Value = DateTimeOffset.Now.AddMinutes(-5) },
-                            EndDate = { Value = DateTimeOffset.Now.AddSeconds(30) }
+                            ],
+                            StartDate = DateTimeOffset.Now.AddMinutes(-5),
+                            EndDate = DateTimeOffset.Now.AddSeconds(30)
                         });
                         return true;
 
@@ -131,13 +131,13 @@ namespace osu.Game.Tests.Visual.UserInterface
                         beatmap.OnlineID = 1001;
                         getRoomRequest.TriggerSuccess(new Room
                         {
-                            RoomID = { Value = 1234 },
+                            RoomID = 1234,
                             Playlist =
-                            {
+                            [
                                 new PlaylistItem(beatmap)
-                            },
-                            StartDate = { Value = DateTimeOffset.Now.AddMinutes(-50) },
-                            EndDate = { Value = DateTimeOffset.Now.AddSeconds(30) }
+                            ],
+                            StartDate = DateTimeOffset.Now.AddMinutes(-50),
+                            EndDate = DateTimeOffset.Now.AddSeconds(30)
                         });
                         return true;