Update c# language version to 9

Directory.Build.props

@@ -1,7 +1,7 @@
 <!-- Contains required properties for osu!framework projects. -->
 <Project>
   <PropertyGroup Label="C#">
-    <LangVersion>8.0</LangVersion>
+    <LangVersion>9.0</LangVersion>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <Nullable>enable</Nullable>
   </PropertyGroup>

osu.Android.props

@@ -52,7 +52,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="ppy.osu.Game.Resources" Version="2022.623.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.621.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.624.1" />
   </ItemGroup>
   <ItemGroup Label="Transitive Dependencies">
     <!-- Realm needs to be directly referenced in all Xamarin projects, as it will not pull in its transitive dependencies otherwise. -->

osu.Desktop/DiscordRichPresence.cs

@@ -57,7 +57,7 @@ private void load(OsuConfigManager config)
             client.OnReady += onReady;
 
             // safety measure for now, until we performance test / improve backoff for failed connections.
-            client.OnConnectionFailed += (_, __) => client.Deinitialize();
+            client.OnConnectionFailed += (_, _) => client.Deinitialize();
 
             client.OnError += (_, e) => Logger.Log($"An error occurred with Discord RPC Client: {e.Code} {e.Message}", LoggingTarget.Network);
 

osu.Desktop/Program.cs

@@ -129,18 +129,18 @@ private static bool trySendIPCMessage(IIpcHost host, string cwd, string[] args)
         [SupportedOSPlatform("windows")]
         private static void setupSquirrel()
         {
-            SquirrelAwareApp.HandleEvents(onInitialInstall: (version, tools) =>
+            SquirrelAwareApp.HandleEvents(onInitialInstall: (_, tools) =>
             {
                 tools.CreateShortcutForThisExe();
                 tools.CreateUninstallerRegistryEntry();
-            }, onAppUpdate: (version, tools) =>
+            }, onAppUpdate: (_, tools) =>
             {
                 tools.CreateUninstallerRegistryEntry();
-            }, onAppUninstall: (version, tools) =>
+            }, onAppUninstall: (_, tools) =>
             {
                 tools.RemoveShortcutForThisExe();
                 tools.RemoveUninstallerRegistryEntry();
-            }, onEveryRun: (version, tools, firstRun) =>
+            }, onEveryRun: (_, _, _) =>
             {
                 // While setting the `ProcessAppUserModelId` fixes duplicate icons/shortcuts on the taskbar, it currently
                 // causes the right-click context menu to function incorrectly.

osu.Game.Benchmarks/BenchmarkRealmReads.cs

@@ -31,7 +31,7 @@ public override void SetUp()
 
             realm = new RealmAccess(storage, OsuGameBase.CLIENT_DATABASE_FILENAME);
 
-            realm.Run(r =>
+            realm.Run(_ =>
             {
                 realm.Write(c => c.Add(TestResources.CreateTestBeatmapSetInfo(rulesets: new[] { new OsuRuleset().RulesetInfo })));
             });

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

@@ -92,7 +92,7 @@ public void TestRemoveVertices()
                 new JuiceStreamPathVertex(20, -5)
             }));
 
-            removeCount = path.RemoveVertices((_, i) => true);
+            removeCount = path.RemoveVertices((_, _) => true);
             Assert.That(removeCount, Is.EqualTo(1));
             Assert.That(path.Vertices, Is.EqualTo(new[]
             {

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

@@ -33,7 +33,7 @@ public void TestHyperDash()
                 hyperDashCount = 0;
 
                 // this needs to be done within the frame stable context due to how quickly hyperdash state changes occur.
-                Player.DrawableRuleset.FrameStableComponents.OnUpdate += d =>
+                Player.DrawableRuleset.FrameStableComponents.OnUpdate += _ =>
                 {
                     var catcher = Player.ChildrenOfType<Catcher>().FirstOrDefault();
 

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

@@ -135,15 +135,15 @@ private PalpableCatchHitObject getDistanceSnapGridSourceHitObject()
         {
             switch (BlueprintContainer.CurrentTool)
             {
-                case SelectTool _:
+                case SelectTool:
                     if (EditorBeatmap.SelectedHitObjects.Count == 0)
                         return null;
 
                     double minTime = EditorBeatmap.SelectedHitObjects.Min(hitObject => hitObject.StartTime);
                     return getLastSnappableHitObject(minTime);
 
-                case FruitCompositionTool _:
-                case JuiceStreamCompositionTool _:
+                case FruitCompositionTool:
+                case JuiceStreamCompositionTool:
                     if (!CursorInPlacementArea)
                         return null;
 

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

@@ -42,10 +42,10 @@ public static PositionRange GetPositionRange(HitObject hitObject)
                 case Droplet droplet:
                     return droplet is TinyDroplet ? PositionRange.EMPTY : new PositionRange(droplet.OriginalX);
 
-                case JuiceStream _:
+                case JuiceStream:
                     return GetPositionRange(hitObject.NestedHitObjects);
 
-                case BananaShower _:
+                case BananaShower:
                     // A banana shower occupies the whole screen width.
                     return new PositionRange(0, CatchPlayfield.WIDTH);
 

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

@@ -131,7 +131,7 @@ private bool handleFlip(PositionRange selectionRange, CatchHitObject hitObject,
         {
             switch (hitObject)
             {
-                case BananaShower _:
+                case BananaShower:
                     return false;
 
                 case JuiceStream juiceStream:

osu.Game.Rulesets.Catch/UI/Catcher.cs

@@ -389,13 +389,13 @@ private CaughtObject getCaughtObject(PalpableCatchHitObject source)
         {
             switch (source)
             {
-                case Fruit _:
+                case Fruit:
                     return caughtFruitPool.Get();
 
-                case Banana _:
+                case Banana:
                     return caughtBananaPool.Get();
 
-                case Droplet _:
+                case Droplet:
                     return caughtDropletPool.Get();
 
                 default:

osu.Game.Rulesets.Mania/Beatmaps/ManiaBeatmapConverter.cs

@@ -173,7 +173,7 @@ private IEnumerable<ManiaHitObject> generateConverted(HitObject original, IBeatm
 
             switch (original)
             {
-                case IHasDistance _:
+                case IHasDistance:
                 {
                     var generator = new DistanceObjectPatternGenerator(Random, original, beatmap, lastPattern, originalBeatmap);
                     conversion = generator;

osu.Game.Rulesets.Mania/Difficulty/ManiaDifficultyCalculator.cs

@@ -156,9 +156,9 @@ private double getScoreMultiplier(Mod[] mods)
             {
                 switch (m)
                 {
-                    case ManiaModNoFail _:
-                    case ManiaModEasy _:
-                    case ManiaModHalfTime _:
+                    case ManiaModNoFail:
+                    case ManiaModEasy:
+                    case ManiaModHalfTime:
                         scoreMultiplier *= 0.5;
                         break;
                 }

osu.Game.Rulesets.Mania/ManiaRuleset.cs

@@ -146,56 +146,56 @@ public override LegacyMods ConvertToLegacyMods(Mod[] mods)
             {
                 switch (mod)
                 {
-                    case ManiaModKey1 _:
+                    case ManiaModKey1:
                         value |= LegacyMods.Key1;
                         break;
 
-                    case ManiaModKey2 _:
+                    case ManiaModKey2:
                         value |= LegacyMods.Key2;
                         break;
 
-                    case ManiaModKey3 _:
+                    case ManiaModKey3:
                         value |= LegacyMods.Key3;
                         break;
 
-                    case ManiaModKey4 _:
+                    case ManiaModKey4:
                         value |= LegacyMods.Key4;
                         break;
 
-                    case ManiaModKey5 _:
+                    case ManiaModKey5:
                         value |= LegacyMods.Key5;
                         break;
 
-                    case ManiaModKey6 _:
+                    case ManiaModKey6:
                         value |= LegacyMods.Key6;
                         break;
 
-                    case ManiaModKey7 _:
+                    case ManiaModKey7:
                         value |= LegacyMods.Key7;
                         break;
 
-                    case ManiaModKey8 _:
+                    case ManiaModKey8:
                         value |= LegacyMods.Key8;
                         break;
 
-                    case ManiaModKey9 _:
+                    case ManiaModKey9:
                         value |= LegacyMods.Key9;
                         break;
 
-                    case ManiaModDualStages _:
+                    case ManiaModDualStages:
                         value |= LegacyMods.KeyCoop;
                         break;
 
-                    case ManiaModFadeIn _:
+                    case ManiaModFadeIn:
                         value |= LegacyMods.FadeIn;
                         value &= ~LegacyMods.Hidden; // this is toggled on in the base call due to inheritance, but we don't want that.
                         break;
 
-                    case ManiaModMirror _:
+                    case ManiaModMirror:
                         value |= LegacyMods.Mirror;
                         break;
 
-                    case ManiaModRandom _:
+                    case ManiaModRandom:
                         value |= LegacyMods.Random;
                         break;
                 }

osu.Game.Rulesets.Mania/Mods/ManiaModRandom.cs

@@ -24,7 +24,7 @@ public void ApplyToBeatmap(IBeatmap beatmap)
             var rng = new Random((int)Seed.Value);
 
             int availableColumns = ((ManiaBeatmap)beatmap).TotalColumns;
-            var shuffledColumns = Enumerable.Range(0, availableColumns).OrderBy(item => rng.Next()).ToList();
+            var shuffledColumns = Enumerable.Range(0, availableColumns).OrderBy(_ => rng.Next()).ToList();
 
             beatmap.HitObjects.OfType<ManiaHitObject>().ForEach(h => h.Column = shuffledColumns[h.Column]);
         }

osu.Game.Rulesets.Mania/Replays/ManiaAutoGenerator.cs

@@ -57,11 +57,11 @@ protected override void GenerateFrames()
                 {
                     switch (point)
                     {
-                        case HitPoint _:
+                        case HitPoint:
                             actions.Add(columnActions[point.Column]);
                             break;
 
-                        case ReleasePoint _:
+                        case ReleasePoint:
                             actions.Remove(columnActions[point.Column]);
                             break;
                     }

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

@@ -76,7 +76,7 @@ public void TestTexturePriorities(string[] textureFilenames, string priorityLook
                 skin.Setup(s => s.GetTexture(It.IsAny<string>())).CallBase();
 
                 skin.Setup(s => s.GetTexture(It.IsIn(textureFilenames), It.IsAny<WrapMode>(), It.IsAny<WrapMode>()))
-                    .Returns((string componentName, WrapMode _, WrapMode __) => new Texture(1, 1) { AssetName = componentName });
+                    .Returns((string componentName, WrapMode _, WrapMode _) => new Texture(1, 1) { AssetName = componentName });
 
                 Child = new DependencyProvidingContainer
                 {

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

@@ -52,7 +52,7 @@ public void TestSpinnerAutoCompleted()
                         lastResult = null;
 
                         spinner = nextSpinner;
-                        spinner.OnNewResult += (o, result) => lastResult = result;
+                        spinner.OnNewResult += (_, result) => lastResult = result;
                     }
 
                     return lastResult?.Type == HitResult.Great;
@@ -116,7 +116,7 @@ public void TestSpinnerGetsNoBonusScore()
                             return false;
 
                         spinner = nextSpinner;
-                        spinner.OnNewResult += (o, result) => results.Add(result);
+                        spinner.OnNewResult += (_, result) => results.Add(result);
 
                         results.Clear();
                     }

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

@@ -161,7 +161,7 @@ private void addEnsureNoSnakingOutStep(Func<double> startTime, int repeatIndex)
             => addCheckPositionChangeSteps(timeAtRepeat(startTime, repeatIndex), positionAtRepeat(repeatIndex), positionRemainsSame);
 
         private Func<double> timeAtRepeat(Func<double> startTime, int repeatIndex) => () => startTime() + 100 + duration_of_span * repeatIndex;
-        private Func<Vector2> positionAtRepeat(int repeatIndex) => repeatIndex % 2 == 0 ? (Func<Vector2>)getSliderStart : getSliderEnd;
+        private Func<Vector2> positionAtRepeat(int repeatIndex) => repeatIndex % 2 == 0 ? getSliderStart : getSliderEnd;
 
         private List<Vector2> getSliderCurve() => ((PlaySliderBody)drawableSlider.Body.Drawable).CurrentCurve;
         private Vector2 getSliderStart() => getSliderCurve().First();

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

@@ -73,7 +73,7 @@ private void load()
             });
 
             selectedHitObjects = EditorBeatmap.SelectedHitObjects.GetBoundCopy();
-            selectedHitObjects.CollectionChanged += (_, __) => updateDistanceSnapGrid();
+            selectedHitObjects.CollectionChanged += (_, _) => updateDistanceSnapGrid();
 
             placementObject = EditorBeatmap.PlacementObject.GetBoundCopy();
             placementObject.ValueChanged += _ => updateDistanceSnapGrid();
@@ -204,7 +204,7 @@ private void updateDistanceSnapGrid()
 
             switch (BlueprintContainer.CurrentTool)
             {
-                case SelectTool _:
+                case SelectTool:
                     if (!EditorBeatmap.SelectedHitObjects.Any())
                         return;
 

osu.Game.Rulesets.Osu/Mods/OsuModApproachDifferent.cs

@@ -37,7 +37,7 @@ public class OsuModApproachDifferent : Mod, IApplicableToDrawableHitObject, IReq
 
         public void ApplyToDrawableHitObject(DrawableHitObject drawable)
         {
-            drawable.ApplyCustomUpdateState += (drawableObject, state) =>
+            drawable.ApplyCustomUpdateState += (drawableObject, _) =>
             {
                 if (!(drawableObject is DrawableHitCircle drawableHitCircle)) return;
 

osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs

@@ -88,7 +88,7 @@ private void applyHiddenState(DrawableHitObject drawableObject, bool increaseVis
 
             switch (drawableObject)
             {
-                case DrawableSliderTail _:
+                case DrawableSliderTail:
                     using (drawableObject.BeginAbsoluteSequence(fadeStartTime))
                         drawableObject.FadeOut(fadeDuration);
 
@@ -165,14 +165,14 @@ private void applyHiddenState(DrawableHitObject drawableObject, bool increaseVis
 
                 switch (hitObject)
                 {
-                    case Slider _:
+                    case Slider:
                         return (fadeOutStartTime, longFadeDuration);
 
-                    case SliderTick _:
+                    case SliderTick:
                         double tickFadeOutDuration = Math.Min(hitObject.TimePreempt - DrawableSliderTick.ANIM_DURATION, 1000);
                         return (hitObject.StartTime - tickFadeOutDuration, tickFadeOutDuration);
 
-                    case Spinner _:
+                    case Spinner:
                         return (fadeOutStartTime + longFadeDuration, fadeOutDuration);
 
                     default:

osu.Game.Rulesets.Osu/Mods/OsuModObjectScaleTween.cs

@@ -44,13 +44,13 @@ private void applyCustomState(DrawableHitObject drawable, ArmedState state)
             // apply grow effect
             switch (drawable)
             {
-                case DrawableSliderHead _:
-                case DrawableSliderTail _:
+                case DrawableSliderHead:
+                case DrawableSliderTail:
                     // special cases we should *not* be scaling.
                     break;
 
-                case DrawableSlider _:
-                case DrawableHitCircle _:
+                case DrawableSlider:
+                case DrawableHitCircle:
                 {
                     using (drawable.BeginAbsoluteSequence(h.StartTime - h.TimePreempt))
                         drawable.ScaleTo(StartScale.Value).Then().ScaleTo(EndScale, h.TimePreempt, Easing.OutSine);

osu.Game.Rulesets.Osu/Mods/OsuModTransform.cs

@@ -34,10 +34,10 @@ private void applyTransform(DrawableHitObject drawable, ArmedState state)
         {
             switch (drawable)
             {
-                case DrawableSliderHead _:
-                case DrawableSliderTail _:
-                case DrawableSliderTick _:
-                case DrawableSliderRepeat _:
+                case DrawableSliderHead:
+                case DrawableSliderTail:
+                case DrawableSliderTick:
+                case DrawableSliderRepeat:
                     return;
 
                 default:

osu.Game.Rulesets.Osu/Objects/Slider.cs

@@ -156,7 +156,7 @@ public int RepeatCount
 
         public Slider()
         {
-            SamplesBindable.CollectionChanged += (_, __) => UpdateNestedSamples();
+            SamplesBindable.CollectionChanged += (_, _) => UpdateNestedSamples();
             Path.Version.ValueChanged += _ => updateNestedPositions();
         }