Merge branch 'master' into osu-random-mod-improvements

.config/dotnet-tools.json

@@ -27,7 +27,7 @@
       ]
     },
     "ppy.localisationanalyser.tools": {
-      "version": "2021.608.0",
+      "version": "2021.705.0",
       "commands": [
         "localisation"
       ]

.editorconfig

@@ -157,7 +157,7 @@ csharp_style_unused_value_assignment_preference = discard_variable:warning
 
 #Style - variable declaration
 csharp_style_inlined_variable_declaration = true:warning
-csharp_style_deconstructed_variable_declaration = true:warning
+csharp_style_deconstructed_variable_declaration = false:silent
 
 #Style - other C# 7.x features
 dotnet_style_prefer_inferred_tuple_names = true:warning
@@ -168,8 +168,8 @@ dotnet_style_prefer_is_null_check_over_reference_equality_method = true:silent
 #Style - C# 8 features
 csharp_prefer_static_local_function = true:warning
 csharp_prefer_simple_using_statement = true:silent
-csharp_style_prefer_index_operator = true:warning
-csharp_style_prefer_range_operator = true:warning
+csharp_style_prefer_index_operator = false:silent
+csharp_style_prefer_range_operator = false:silent
 csharp_style_prefer_switch_expression = false:none
 
 #Supressing roslyn built-in analyzers

README.md

@@ -11,7 +11,7 @@
 
 A free-to-win rhythm game. Rhythm is just a *click* away!
 
-The future of [osu!](https://osu.ppy.sh) and the beginning of an open era! Commonly known by the codename *osu!lazer*. Pew pew.
+The future of [osu!](https://osu.ppy.sh) and the beginning of an open era! Currently known by and released under the codename "*lazer*". As in sharper than cutting-edge.
 
 ## Status
 
@@ -23,7 +23,7 @@ We are accepting bug reports (please report with as much detail as possible and
 
 - Detailed release changelogs are available on the [official osu! site](https://osu.ppy.sh/home/changelog/lazer).
 - You can learn more about our approach to [project management](https://github.com/ppy/osu/wiki/Project-management).
-- Read peppy's [latest blog post](https://blog.ppy.sh/a-definitive-lazer-faq/) exploring where lazer is currently and the roadmap going forward.
+- Read peppy's [latest blog post](https://blog.ppy.sh/a-definitive-lazer-faq/) exploring where the project is currently and the roadmap going forward.
 
 ## Running osu!
 

Templates/Rulesets/ruleset-empty/osu.Game.Rulesets.EmptyFreeform.Tests/osu.Game.Rulesets.EmptyFreeform.Tests.csproj

@@ -12,7 +12,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <ItemGroup>

Templates/Rulesets/ruleset-example/osu.Game.Rulesets.Pippidon.Tests/osu.Game.Rulesets.Pippidon.Tests.csproj

@@ -12,7 +12,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <ItemGroup>

Templates/Rulesets/ruleset-scrolling-empty/osu.Game.Rulesets.EmptyScrolling.Tests/osu.Game.Rulesets.EmptyScrolling.Tests.csproj

@@ -12,7 +12,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <ItemGroup>

Templates/Rulesets/ruleset-scrolling-example/osu.Game.Rulesets.Pippidon.Tests/osu.Game.Rulesets.Pippidon.Tests.csproj

@@ -12,7 +12,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <ItemGroup>

osu.Android.props

@@ -51,11 +51,11 @@
     <Reference Include="Java.Interop" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="ppy.osu.Game.Resources" Version="2021.618.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2021.628.0" />
+    <PackageReference Include="ppy.osu.Game.Resources" Version="2021.706.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2021.713.0" />
   </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. -->
-    <PackageReference Include="Realm" Version="10.2.0" />
+    <PackageReference Include="Realm" Version="10.3.0" />
   </ItemGroup>
 </Project>

osu.Desktop/Updater/SquirrelUpdateManager.cs

@@ -68,6 +68,8 @@ namespace osu.Desktop.Updater
                     return false;
                 }
 
+                scheduleRecheck = false;
+
                 if (notification == null)
                 {
                     notification = new UpdateProgressNotification(this) { State = ProgressNotificationState.Active };
@@ -98,7 +100,6 @@ namespace osu.Desktop.Updater
                         // could fail if deltas are unavailable for full update path (https://github.com/Squirrel/Squirrel.Windows/issues/959)
                         // try again without deltas.
                         await checkForUpdateAsync(false, notification).ConfigureAwait(false);
-                        scheduleRecheck = false;
                     }
                     else
                     {
@@ -110,13 +111,14 @@ namespace osu.Desktop.Updater
             catch (Exception)
             {
                 // we'll ignore this and retry later. can be triggered by no internet connection or thread abortion.
+                scheduleRecheck = true;
             }
             finally
             {
                 if (scheduleRecheck)
                 {
                     // check again in 30 minutes.
-                    Scheduler.AddDelayed(async () => await checkForUpdateAsync().ConfigureAwait(false), 60000 * 30);
+                    Scheduler.AddDelayed(() => Task.Run(async () => await checkForUpdateAsync().ConfigureAwait(false)), 60000 * 30);
                 }
             }
 
@@ -141,7 +143,7 @@ namespace osu.Desktop.Updater
                 Activated = () =>
                 {
                     updateManager.PrepareUpdateAsync()
-                                 .ContinueWith(_ => updateManager.Schedule(() => game.GracefullyExit()));
+                                 .ContinueWith(_ => updateManager.Schedule(() => game?.GracefullyExit()));
                     return true;
                 };
             }

osu.Desktop/osu.Desktop.csproj

@@ -5,8 +5,8 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Description>A free-to-win rhythm game. Rhythm is just a *click* away!</Description>
     <AssemblyName>osu!</AssemblyName>
-    <Title>osu!lazer</Title>
-    <Product>osu!lazer</Product>
+    <Title>osu!</Title>
+    <Product>osu!</Product>
     <ApplicationIcon>lazer.ico</ApplicationIcon>
     <ApplicationManifest>app.manifest</ApplicationManifest>
     <Version>0.0.0</Version>

osu.Desktop/osu.nuspec

@@ -3,7 +3,7 @@
     <metadata>
         <id>osulazer</id>
         <version>0.0.0</version>
-        <title>osu!lazer</title>
+        <title>osu!</title>
         <authors>ppy Pty Ltd</authors>
         <owners>Dean Herbert</owners>
         <projectUrl>https://osu.ppy.sh/</projectUrl>
@@ -20,4 +20,3 @@
       <file src="**.config" target="lib\net45\"/>
     </files>
 </package>
-

osu.Game.Benchmarks/osu.Game.Benchmarks.csproj

@@ -9,7 +9,7 @@
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.13.0" />
     <PackageReference Include="nunit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
   </ItemGroup>
 
   <ItemGroup>

osu.Game.Rulesets.Catch.Tests/Editor/CatchEditorTestSceneContainer.cs

@@ -0,0 +1,66 @@
+// 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.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Timing;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Catch.Edit;
+using osu.Game.Rulesets.Catch.UI;
+using osu.Game.Rulesets.UI;
+using osu.Game.Rulesets.UI.Scrolling;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Rulesets.Catch.Tests.Editor
+{
+    public class CatchEditorTestSceneContainer : Container
+    {
+        [Cached(typeof(Playfield))]
+        public readonly ScrollingPlayfield Playfield;
+
+        protected override Container<Drawable> Content { get; }
+
+        public CatchEditorTestSceneContainer()
+        {
+            Anchor = Anchor.Centre;
+            Origin = Anchor.Centre;
+            Width = CatchPlayfield.WIDTH;
+            Height = 1000;
+            Padding = new MarginPadding
+            {
+                Bottom = 100
+            };
+
+            InternalChildren = new Drawable[]
+            {
+                new ScrollingTestContainer(ScrollingDirection.Down)
+                {
+                    TimeRange = 1000,
+                    RelativeSizeAxes = Axes.Both,
+                    Child = Playfield = new TestCatchPlayfield
+                    {
+                        RelativeSizeAxes = Axes.Both
+                    }
+                },
+                new PlayfieldBorder
+                {
+                    PlayfieldBorderStyle = { Value = PlayfieldBorderStyle.Full },
+                    Clock = new FramedClock(new StopwatchClock(true))
+                },
+                Content = new Container
+                {
+                    RelativeSizeAxes = Axes.Both
+                }
+            };
+        }
+
+        private class TestCatchPlayfield : CatchEditorPlayfield
+        {
+            public TestCatchPlayfield()
+                : base(new BeatmapDifficulty { CircleSize = 0 })
+            {
+            }
+        }
+    }
+}

osu.Game.Rulesets.Catch.Tests/Editor/CatchPlacementBlueprintTestScene.cs

@@ -0,0 +1,79 @@
+// 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 System.Collections.Generic;
+using NUnit.Framework;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Testing;
+using osu.Framework.Timing;
+using osu.Game.Rulesets.Catch.Edit.Blueprints.Components;
+using osu.Game.Rulesets.Catch.Objects.Drawables;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.UI.Scrolling;
+using osu.Game.Tests.Visual;
+using osuTK;
+using osuTK.Input;
+
+namespace osu.Game.Rulesets.Catch.Tests.Editor
+{
+    public abstract class CatchPlacementBlueprintTestScene : PlacementBlueprintTestScene
+    {
+        protected const double TIME_SNAP = 100;
+
+        protected DrawableCatchHitObject LastObject;
+
+        protected new ScrollingHitObjectContainer HitObjectContainer => contentContainer.Playfield.HitObjectContainer;
+
+        protected override Container<Drawable> Content => contentContainer;
+
+        private readonly CatchEditorTestSceneContainer contentContainer;
+
+        protected CatchPlacementBlueprintTestScene()
+        {
+            base.Content.Add(contentContainer = new CatchEditorTestSceneContainer());
+
+            contentContainer.Playfield.Clock = new FramedClock(new ManualClock());
+        }
+
+        [SetUp]
+        public void Setup() => Schedule(() =>
+        {
+            HitObjectContainer.Clear();
+            ResetPlacement();
+            LastObject = null;
+        });
+
+        protected void AddMoveStep(double time, float x) => AddStep($"move to time={time}, x={x}", () =>
+        {
+            float y = HitObjectContainer.PositionAtTime(time);
+            Vector2 pos = HitObjectContainer.ToScreenSpace(new Vector2(x, y + HitObjectContainer.DrawHeight));
+            InputManager.MoveMouseTo(pos);
+        });
+
+        protected void AddClickStep(MouseButton button) => AddStep($"click {button}", () =>
+        {
+            InputManager.Click(button);
+        });
+
+        protected IEnumerable<FruitOutline> FruitOutlines => Content.ChildrenOfType<FruitOutline>();
+
+        // Unused because AddHitObject is overriden
+        protected override Container CreateHitObjectContainer() => new Container();
+
+        protected override void AddHitObject(DrawableHitObject hitObject)
+        {
+            LastObject = (DrawableCatchHitObject)hitObject;
+            contentContainer.Playfield.HitObjectContainer.Add(hitObject);
+        }
+
+        protected override SnapResult SnapForBlueprint(PlacementBlueprint blueprint)
+        {
+            var result = base.SnapForBlueprint(blueprint);
+            result.Time = Math.Round(HitObjectContainer.TimeAtScreenSpacePosition(result.ScreenSpacePosition) / TIME_SNAP) * TIME_SNAP;
+            return result;
+        }
+    }
+}

osu.Game.Rulesets.Catch.Tests/Editor/CatchSelectionBlueprintTestScene.cs

@@ -0,0 +1,24 @@
+// 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.Framework.Graphics.Containers;
+using osu.Game.Rulesets.UI.Scrolling;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Rulesets.Catch.Tests.Editor
+{
+    public abstract class CatchSelectionBlueprintTestScene : SelectionBlueprintTestScene
+    {
+        protected ScrollingHitObjectContainer HitObjectContainer => contentContainer.Playfield.HitObjectContainer;
+
+        protected override Container<Drawable> Content => contentContainer;
+
+        private readonly CatchEditorTestSceneContainer contentContainer;
+
+        protected CatchSelectionBlueprintTestScene()
+        {
+            base.Content.Add(contentContainer = new CatchEditorTestSceneContainer());
+        }
+    }
+}

osu.Game.Rulesets.Catch.Tests/Editor/TestSceneBananaShowerPlacementBlueprint.cs

@@ -0,0 +1,87 @@
+// 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.Testing;
+using osu.Framework.Utils;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Catch.Edit.Blueprints;
+using osu.Game.Rulesets.Catch.Edit.Blueprints.Components;
+using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.Catch.Objects.Drawables;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
+using osuTK.Input;
+
+namespace osu.Game.Rulesets.Catch.Tests.Editor
+{
+    public class TestSceneBananaShowerPlacementBlueprint : CatchPlacementBlueprintTestScene
+    {
+        protected override DrawableHitObject CreateHitObject(HitObject hitObject) => new DrawableBananaShower((BananaShower)hitObject);
+
+        protected override PlacementBlueprint CreateBlueprint() => new BananaShowerPlacementBlueprint();
+
+        protected override void AddHitObject(DrawableHitObject hitObject)
+        {
+            // Create nested bananas (but positions are not randomized because beatmap processing is not done).
+            hitObject.HitObject.ApplyDefaults(new ControlPointInfo(), Beatmap.Value.BeatmapInfo.BaseDifficulty);
+
+            base.AddHitObject(hitObject);
+        }
+
+        [Test]
+        public void TestBasicPlacement()
+        {
+            const double start_time = 100;
+            const double end_time = 500;
+
+            AddMoveStep(start_time, 0);
+            AddClickStep(MouseButton.Left);
+            AddMoveStep(end_time, 0);
+            AddClickStep(MouseButton.Right);
+            AddAssert("banana shower is placed", () => LastObject is DrawableBananaShower);
+            AddAssert("start time is correct", () => Precision.AlmostEquals(LastObject.HitObject.StartTime, start_time));
+            AddAssert("end time is correct", () => Precision.AlmostEquals(LastObject.HitObject.GetEndTime(), end_time));
+        }
+
+        [Test]
+        public void TestReversePlacement()
+        {
+            const double start_time = 100;
+            const double end_time = 500;
+
+            AddMoveStep(end_time, 0);
+            AddClickStep(MouseButton.Left);
+            AddMoveStep(start_time, 0);
+            AddClickStep(MouseButton.Right);
+            AddAssert("start time is correct", () => Precision.AlmostEquals(LastObject.HitObject.StartTime, start_time));
+            AddAssert("end time is correct", () => Precision.AlmostEquals(LastObject.HitObject.GetEndTime(), end_time));
+        }
+
+        [Test]
+        public void TestFinishWithZeroDuration()
+        {
+            AddMoveStep(100, 0);
+            AddClickStep(MouseButton.Left);
+            AddClickStep(MouseButton.Right);
+            AddAssert("banana shower is not placed", () => LastObject == null);
+            AddAssert("state is waiting", () => CurrentBlueprint?.PlacementActive == PlacementBlueprint.PlacementState.Waiting);
+        }
+
+        [Test]
+        public void TestOpacity()
+        {
+            AddMoveStep(100, 0);
+            AddClickStep(MouseButton.Left);
+            AddUntilStep("outline is semitransparent", () => Precision.DefinitelyBigger(1, timeSpanOutline.Alpha));
+            AddMoveStep(200, 0);
+            AddUntilStep("outline is opaque", () => Precision.AlmostEquals(timeSpanOutline.Alpha, 1));
+            AddMoveStep(100, 0);
+            AddUntilStep("outline is semitransparent", () => Precision.DefinitelyBigger(1, timeSpanOutline.Alpha));
+        }
+
+        private TimeSpanOutline timeSpanOutline => Content.ChildrenOfType<TimeSpanOutline>().Single();
+    }
+}

osu.Game.Rulesets.Catch.Tests/Editor/TestSceneFruitPlacementBlueprint.cs

@@ -0,0 +1,44 @@
+// 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.Utils;
+using osu.Game.Rulesets.Catch.Edit.Blueprints;
+using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.Catch.Objects.Drawables;
+using osu.Game.Rulesets.Catch.UI;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
+using osuTK.Input;
+
+namespace osu.Game.Rulesets.Catch.Tests.Editor
+{
+    public class TestSceneFruitPlacementBlueprint : CatchPlacementBlueprintTestScene
+    {
+        protected override DrawableHitObject CreateHitObject(HitObject hitObject) => new DrawableFruit((Fruit)hitObject);
+
+        protected override PlacementBlueprint CreateBlueprint() => new FruitPlacementBlueprint();
+
+        [Test]
+        public void TestFruitPlacementPosition()
+        {
+            const double time = 300;
+            const float x = CatchPlayfield.CENTER_X;
+
+            AddMoveStep(time, x);
+            AddClickStep(MouseButton.Left);
+
+            AddAssert("outline position is correct", () =>
+            {
+                var outline = FruitOutlines.Single();
+                return Precision.AlmostEquals(outline.X, x) &&
+                       Precision.AlmostEquals(outline.Y, HitObjectContainer.PositionAtTime(time));
+            });
+
+            AddAssert("fruit time is correct", () => Precision.AlmostEquals(LastObject.StartTimeBindable.Value, time));
+            AddAssert("fruit position is correct", () => Precision.AlmostEquals(LastObject.X, x));
+        }
+    }
+}

osu.Game.Rulesets.Catch.Tests/Editor/TestSceneJuiceStreamSelectionBlueprint.cs

@@ -0,0 +1,38 @@
+// 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.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Catch.Edit.Blueprints;
+using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+using osuTK;
+
+namespace osu.Game.Rulesets.Catch.Tests.Editor
+{
+    public class TestSceneJuiceStreamSelectionBlueprint : CatchSelectionBlueprintTestScene
+    {
+        public TestSceneJuiceStreamSelectionBlueprint()
+        {
+            var hitObject = new JuiceStream
+            {
+                OriginalX = 100,
+                StartTime = 100,
+                Path = new SliderPath(PathType.PerfectCurve, new[]
+                {
+                    Vector2.Zero,
+                    new Vector2(200, 100),
+                    new Vector2(0, 200),
+                }),
+            };
+            var controlPoint = new ControlPointInfo();
+            controlPoint.Add(0, new TimingControlPoint
+            {
+                BeatLength = 100
+            });
+            hitObject.ApplyDefaults(controlPoint, new BeatmapDifficulty { CircleSize = 0 });
+            AddBlueprint(new JuiceStreamSelectionBlueprint(hitObject));
+        }
+    }
+}

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

@@ -0,0 +1,114 @@
+// 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.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Testing;
+using osu.Framework.Utils;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Catch.Judgements;
+using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.Catch.Objects.Drawables;
+using osu.Game.Rulesets.Catch.Skinning;
+using osu.Game.Rulesets.Catch.UI;
+using osu.Game.Skinning;
+using osu.Game.Tests.Visual;
+using Direction = osu.Game.Rulesets.Catch.UI.Direction;
+
+namespace osu.Game.Rulesets.Catch.Tests
+{
+    public class TestSceneCatchSkinConfiguration : OsuTestScene
+    {
+        [Cached]
+        private readonly DroppedObjectContainer droppedObjectContainer;
+
+        private Catcher catcher;
+
+        private readonly Container container;
+
+        public TestSceneCatchSkinConfiguration()
+        {
+            Add(droppedObjectContainer = new DroppedObjectContainer());
+            Add(container = new Container { RelativeSizeAxes = Axes.Both });
+        }
+
+        [TestCase(false)]
+        [TestCase(true)]
+        public void TestCatcherPlateFlipping(bool flip)
+        {
+            AddStep("setup catcher", () =>
+            {
+                var skin = new TestSkin { FlipCatcherPlate = flip };
+                container.Child = new SkinProvidingContainer(skin)
+                {
+                    Child = catcher = new Catcher(new Container())
+                    {
+                        Anchor = Anchor.Centre
+                    }
+                };
+            });
+
+            Fruit fruit = new Fruit();
+
+            AddStep("catch fruit", () => catchFruit(fruit, 20));
+
+            float position = 0;
+
+            AddStep("record fruit position", () => position = getCaughtObjectPosition(fruit));
+
+            AddStep("face left", () => catcher.VisualDirection = Direction.Left);
+
+            if (flip)
+                AddAssert("fruit position changed", () => !Precision.AlmostEquals(getCaughtObjectPosition(fruit), position));
+            else
+                AddAssert("fruit position unchanged", () => Precision.AlmostEquals(getCaughtObjectPosition(fruit), position));
+
+            AddStep("face right", () => catcher.VisualDirection = Direction.Right);
+
+            AddAssert("fruit position restored", () => Precision.AlmostEquals(getCaughtObjectPosition(fruit), position));
+        }
+
+        private float getCaughtObjectPosition(Fruit fruit)
+        {
+            var caughtObject = catcher.ChildrenOfType<CaughtObject>().Single(c => c.HitObject == fruit);
+            return caughtObject.Parent.ToSpaceOfOtherDrawable(caughtObject.Position, catcher).X;
+        }
+
+        private void catchFruit(Fruit fruit, float x)
+        {
+            fruit.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+            var drawableFruit = new DrawableFruit(fruit) { X = x };
+            var judgement = fruit.CreateJudgement();
+            catcher.OnNewResult(drawableFruit, new CatchJudgementResult(fruit, judgement)
+            {
+                Type = judgement.MaxResult
+            });
+        }
+
+        private class TestSkin : DefaultSkin
+        {
+            public bool FlipCatcherPlate { get; set; }
+
+            public TestSkin()
+                : base(null)
+            {
+            }
+
+            public override IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup)
+            {
+                if (lookup is CatchSkinConfiguration config)
+                {
+                    if (config == CatchSkinConfiguration.FlipCatcherPlate)
+                        return SkinUtils.As<TValue>(new Bindable<bool>(FlipCatcherPlate));
+                }
+
+                return base.GetConfig<TLookup, TValue>(lookup);
+            }
+        }
+    }
+}

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

@@ -194,9 +194,9 @@ namespace osu.Game.Rulesets.Catch.Tests
             AddStep("catch more fruits", () => attemptCatch(() => new Fruit(), 9));
             checkPlate(10);
             AddAssert("caught objects are stacked", () =>
-                catcher.CaughtObjects.All(obj => obj.Y <= Catcher.CAUGHT_FRUIT_VERTICAL_OFFSET) &&
-                catcher.CaughtObjects.Any(obj => obj.Y == Catcher.CAUGHT_FRUIT_VERTICAL_OFFSET) &&
-                catcher.CaughtObjects.Any(obj => obj.Y < -25));
+                catcher.CaughtObjects.All(obj => obj.Y <= 0) &&
+                catcher.CaughtObjects.Any(obj => obj.Y == 0) &&
+                catcher.CaughtObjects.Any(obj => obj.Y < 0));
         }
 
         [Test]

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

@@ -138,7 +138,7 @@ namespace osu.Game.Rulesets.Catch.Tests
 
             AddStep("finish hyper-dashing", () =>
             {
-                catcherArea.MovableCatcher.SetHyperDashState(1);
+                catcherArea.MovableCatcher.SetHyperDashState();
                 catcherArea.MovableCatcher.FinishTransforms();
             });
 

osu.Game.Rulesets.Catch.Tests/osu.Game.Rulesets.Catch.Tests.csproj

@@ -4,7 +4,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <PropertyGroup Label="Project">

osu.Game.Rulesets.Catch/Edit/Blueprints/CatchPlacementBlueprint.cs

@@ -6,6 +6,7 @@ using osu.Game.Rulesets.Catch.Objects;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.UI;
 using osu.Game.Rulesets.UI.Scrolling;
+using osuTK;
 
 namespace osu.Game.Rulesets.Catch.Edit.Blueprints
 {
@@ -23,5 +24,7 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
             : base(new THitObject())
         {
         }
+
+        public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => true;
     }
 }

osu.Game.Rulesets.Catch/Edit/Blueprints/CatchSelectionBlueprint.cs

@@ -13,6 +13,8 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
     public abstract class CatchSelectionBlueprint<THitObject> : HitObjectSelectionBlueprint<THitObject>
         where THitObject : CatchHitObject
     {
+        protected override bool AlwaysShowWhenSelected => true;
+
         public override Vector2 ScreenSpaceSelectionPoint
         {
             get

osu.Game.Rulesets.Catch/Edit/Blueprints/Components/FruitOutline.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 JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -18,7 +19,6 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints.Components
         {
             Anchor = Anchor.BottomLeft;
             Origin = Anchor.Centre;
-            Size = new Vector2(2 * CatchHitObject.OBJECT_RADIUS);
             InternalChild = new BorderPiece();
         }
 
@@ -28,10 +28,10 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints.Components
             Colour = osuColour.Yellow;
         }
 
-        public void UpdateFrom(ScrollingHitObjectContainer hitObjectContainer, CatchHitObject hitObject)
+        public void UpdateFrom(ScrollingHitObjectContainer hitObjectContainer, CatchHitObject hitObject, [CanBeNull] CatchHitObject parent = null)
         {
-            X = hitObject.EffectiveX;
-            Y = hitObjectContainer.PositionAtTime(hitObject.StartTime);
+            X = hitObject.EffectiveX - (parent?.OriginalX ?? 0);
+            Y = hitObjectContainer.PositionAtTime(hitObject.StartTime, parent?.StartTime ?? hitObjectContainer.Time.Current);
             Scale = new Vector2(hitObject.Scale);
         }
     }

osu.Game.Rulesets.Catch/Edit/Blueprints/Components/NestedOutlineContainer.cs

@@ -0,0 +1,53 @@
+// 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 System.Linq;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Primitives;
+using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.UI.Scrolling;
+
+namespace osu.Game.Rulesets.Catch.Edit.Blueprints.Components
+{
+    public class NestedOutlineContainer : CompositeDrawable
+    {
+        private readonly List<CatchHitObject> nestedHitObjects = new List<CatchHitObject>();
+
+        public NestedOutlineContainer()
+        {
+            Anchor = Anchor.BottomLeft;
+        }
+
+        public void UpdatePositionFrom(ScrollingHitObjectContainer hitObjectContainer, CatchHitObject parentHitObject)
+        {
+            X = parentHitObject.OriginalX;
+            Y = hitObjectContainer.PositionAtTime(parentHitObject.StartTime);
+        }
+
+        public void UpdateNestedObjectsFrom(ScrollingHitObjectContainer hitObjectContainer, CatchHitObject parentHitObject)
+        {
+            nestedHitObjects.Clear();
+            nestedHitObjects.AddRange(parentHitObject.NestedHitObjects
+                                                     .OfType<CatchHitObject>()
+                                                     .Where(h => !(h is TinyDroplet)));
+
+            while (nestedHitObjects.Count < InternalChildren.Count)
+                RemoveInternal(InternalChildren[^1]);
+
+            while (InternalChildren.Count < nestedHitObjects.Count)
+                AddInternal(new FruitOutline());
+
+            for (int i = 0; i < nestedHitObjects.Count; i++)
+            {
+                var hitObject = nestedHitObjects[i];
+                var outline = (FruitOutline)InternalChildren[i];
+                outline.UpdateFrom(hitObjectContainer, hitObject, parentHitObject);
+                outline.Scale *= hitObject is Droplet ? 0.5f : 1;
+            }
+        }
+
+        protected override bool ComputeIsMaskedAway(RectangleF maskingBounds) => false;
+    }
+}

osu.Game.Rulesets.Catch/Edit/Blueprints/Components/ScrollingPath.cs

@@ -0,0 +1,83 @@
+// 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 System.Linq;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Lines;
+using osu.Framework.Graphics.Primitives;
+using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.UI.Scrolling;
+using osuTK;
+
+namespace osu.Game.Rulesets.Catch.Edit.Blueprints.Components
+{
+    public class ScrollingPath : CompositeDrawable
+    {
+        private readonly Path drawablePath;
+
+        private readonly List<(double Distance, float X)> vertices = new List<(double, float)>();
+
+        public ScrollingPath()
+        {
+            Anchor = Anchor.BottomLeft;
+
+            InternalChildren = new Drawable[]
+            {
+                drawablePath = new SmoothPath
+                {
+                    PathRadius = 2,
+                    Alpha = 0.5f
+                },
+            };
+        }
+
+        public void UpdatePositionFrom(ScrollingHitObjectContainer hitObjectContainer, CatchHitObject hitObject)
+        {
+            X = hitObject.OriginalX;
+            Y = hitObjectContainer.PositionAtTime(hitObject.StartTime);
+        }
+
+        public void UpdatePathFrom(ScrollingHitObjectContainer hitObjectContainer, JuiceStream hitObject)
+        {
+            double distanceToYFactor = -hitObjectContainer.LengthAtTime(hitObject.StartTime, hitObject.StartTime + 1 / hitObject.Velocity);
+
+            computeDistanceXs(hitObject);
+            drawablePath.Vertices = vertices
+                                    .Select(v => new Vector2(v.X, (float)(v.Distance * distanceToYFactor)))
+                                    .ToArray();
+            drawablePath.OriginPosition = drawablePath.PositionInBoundingBox(Vector2.Zero);
+        }
+
+        private void computeDistanceXs(JuiceStream hitObject)
+        {
+            vertices.Clear();
+
+            var sliderVertices = new List<Vector2>();
+            hitObject.Path.GetPathToProgress(sliderVertices, 0, 1);
+
+            if (sliderVertices.Count == 0)
+                return;
+
+            double distance = 0;
+            Vector2 lastPosition = Vector2.Zero;
+
+            for (int repeat = 0; repeat < hitObject.RepeatCount + 1; repeat++)
+            {
+                foreach (var position in sliderVertices)
+                {
+                    distance += Vector2.Distance(lastPosition, position);
+                    lastPosition = position;
+
+                    vertices.Add((distance, position.X));
+                }
+
+                sliderVertices.Reverse();
+            }
+        }
+
+        // Because this has 0x0 size, the contents are otherwise masked away if the start position is outside the screen.
+        protected override bool ComputeIsMaskedAway(RectangleF maskingBounds) => false;
+    }
+}

osu.Game.Rulesets.Catch/Edit/Blueprints/JuiceStreamSelectionBlueprint.cs

@@ -3,7 +3,10 @@
 
 using System.Linq;
 using osu.Framework.Allocation;
+using osu.Framework.Caching;
+using osu.Framework.Graphics;
 using osu.Framework.Graphics.Primitives;
+using osu.Game.Rulesets.Catch.Edit.Blueprints.Components;
 using osu.Game.Rulesets.Catch.Objects;
 using osu.Game.Rulesets.Objects;
 using osuTK;
@@ -17,9 +20,20 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
         private float minNestedX;
         private float maxNestedX;
 
+        private readonly ScrollingPath scrollingPath;
+
+        private readonly NestedOutlineContainer nestedOutlineContainer;
+
+        private readonly Cached pathCache = new Cached();
+
         public JuiceStreamSelectionBlueprint(JuiceStream hitObject)
             : base(hitObject)
         {
+            InternalChildren = new Drawable[]
+            {
+                scrollingPath = new ScrollingPath(),
+                nestedOutlineContainer = new NestedOutlineContainer()
+            };
         }
 
         [BackgroundDependencyLoader]
@@ -29,7 +43,28 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
             computeObjectBounds();
         }
 
-        private void onDefaultsApplied(HitObject _) => computeObjectBounds();
+        protected override void Update()
+        {
+            base.Update();
+
+            if (!IsSelected) return;
+
+            scrollingPath.UpdatePositionFrom(HitObjectContainer, HitObject);
+            nestedOutlineContainer.UpdatePositionFrom(HitObjectContainer, HitObject);
+
+            if (pathCache.IsValid) return;
+
+            scrollingPath.UpdatePathFrom(HitObjectContainer, HitObject);
+            nestedOutlineContainer.UpdateNestedObjectsFrom(HitObjectContainer, HitObject);
+
+            pathCache.Validate();
+        }
+
+        private void onDefaultsApplied(HitObject _)
+        {
+            computeObjectBounds();
+            pathCache.Invalidate();
+        }
 
         private void computeObjectBounds()
         {

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

@@ -2,6 +2,8 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Catch.Objects;
 using osu.Game.Rulesets.Edit;
@@ -20,6 +22,16 @@ namespace osu.Game.Rulesets.Catch.Edit
         {
         }
 
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            LayerBelowRuleset.Add(new PlayfieldBorder
+            {
+                RelativeSizeAxes = Axes.Both,
+                PlayfieldBorderStyle = { Value = PlayfieldBorderStyle.Corners }
+            });
+        }
+
         protected override DrawableRuleset<CatchHitObject> CreateDrawableRuleset(Ruleset ruleset, IBeatmap beatmap, IReadOnlyList<Mod> mods = null) =>
             new DrawableCatchEditorRuleset(ruleset, beatmap, mods);
 

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

@@ -1,9 +1,12 @@
 // 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 System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Game.Rulesets.Catch.Objects;
+using osu.Game.Rulesets.Catch.UI;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.UI;
 using osu.Game.Rulesets.UI.Scrolling;
@@ -24,23 +27,90 @@ namespace osu.Game.Rulesets.Catch.Edit
             var blueprint = moveEvent.Blueprint;
             Vector2 originalPosition = HitObjectContainer.ToLocalSpace(blueprint.ScreenSpaceSelectionPoint);
             Vector2 targetPosition = HitObjectContainer.ToLocalSpace(blueprint.ScreenSpaceSelectionPoint + moveEvent.ScreenSpaceDelta);
+
             float deltaX = targetPosition.X - originalPosition.X;
+            deltaX = limitMovement(deltaX, EditorBeatmap.SelectedHitObjects);
+
+            if (deltaX == 0)
+            {
+                // Even if there is no positional change, there may be a time change.
+                return true;
+            }
 
             EditorBeatmap.PerformOnSelection(h =>
             {
                 if (!(h is CatchHitObject hitObject)) return;
 
-                if (hitObject is BananaShower) return;
-
-                // TODO: confine in bounds
-                hitObject.OriginalXBindable.Value += deltaX;
+                hitObject.OriginalX += deltaX;
 
                 // Move the nested hit objects to give an instant result before nested objects are recreated.
                 foreach (var nested in hitObject.NestedHitObjects.OfType<CatchHitObject>())
-                    nested.OriginalXBindable.Value += deltaX;
+                    nested.OriginalX += deltaX;
             });
 
             return true;
         }
+
+        /// <summary>
+        /// Limit positional movement of the objects by the constraint that moved objects should stay in bounds.
+        /// </summary>
+        /// <param name="deltaX">The positional movement.</param>
+        /// <param name="movingObjects">The objects to be moved.</param>
+        /// <returns>The positional movement with the restriction applied.</returns>
+        private float limitMovement(float deltaX, IEnumerable<HitObject> movingObjects)
+        {
+            float minX = float.PositiveInfinity;
+            float maxX = float.NegativeInfinity;
+
+            foreach (float x in movingObjects.SelectMany(getOriginalPositions))
+            {
+                minX = Math.Min(minX, x);
+                maxX = Math.Max(maxX, x);
+            }
+
+            // To make an object with position `x` stay in bounds after `deltaX` movement, `0 <= x + deltaX <= WIDTH` should be satisfied.
+            // Subtracting `x`, we get `-x <= deltaX <= WIDTH - x`.
+            // We only need to apply the inequality to extreme values of `x`.
+            float lowerBound = -minX;
+            float upperBound = CatchPlayfield.WIDTH - maxX;
+            // The inequality may be unsatisfiable if the objects were already out of bounds.
+            // In that case, don't move objects at all.
+            if (lowerBound > upperBound)
+                return 0;
+
+            return Math.Clamp(deltaX, lowerBound, upperBound);
+        }
+
+        /// <summary>
+        /// Enumerate X positions that should be contained in-bounds after move offset is applied.
+        /// </summary>
+        private IEnumerable<float> getOriginalPositions(HitObject hitObject)
+        {
+            switch (hitObject)
+            {
+                case Fruit fruit:
+                    yield return fruit.OriginalX;
+
+                    break;
+
+                case JuiceStream juiceStream:
+                    foreach (var nested in juiceStream.NestedHitObjects.OfType<CatchHitObject>())
+                    {
+                        // Even if `OriginalX` is outside the playfield, tiny droplets can be moved inside the playfield after the random offset application.
+                        if (!(nested is TinyDroplet))
+                            yield return nested.OriginalX;
+                    }
+
+                    break;
+
+                case BananaShower _:
+                    // A banana shower occupies the whole screen width.
+                    // If the selection contains a banana shower, the selection cannot be moved horizontally.
+                    yield return 0;
+                    yield return CatchPlayfield.WIDTH;
+
+                    break;
+            }
+        }
     }
 }

osu.Game.Rulesets.Catch/Mods/CatchModDifficultyAdjust.cs

@@ -12,37 +12,29 @@ namespace osu.Game.Rulesets.Catch.Mods
 {
     public class CatchModDifficultyAdjust : ModDifficultyAdjust, IApplicableToBeatmapProcessor
     {
-        [SettingSource("Circle Size", "Override a beatmap's set CS.", FIRST_SETTING_ORDER - 1)]
-        public BindableNumber<float> CircleSize { get; } = new BindableFloatWithLimitExtension
+        [SettingSource("Circle Size", "Override a beatmap's set CS.", FIRST_SETTING_ORDER - 1, SettingControlType = typeof(DifficultyAdjustSettingsControl))]
+        public DifficultyBindable CircleSize { get; } = new DifficultyBindable
         {
             Precision = 0.1f,
             MinValue = 1,
             MaxValue = 10,
-            Default = 5,
-            Value = 5,
+            ExtendedMaxValue = 11,
+            ReadCurrentFromDifficulty = diff => diff.CircleSize,
         };
 
-        [SettingSource("Approach Rate", "Override a beatmap's set AR.", LAST_SETTING_ORDER + 1)]
-        public BindableNumber<float> ApproachRate { get; } = new BindableFloatWithLimitExtension
+        [SettingSource("Approach Rate", "Override a beatmap's set AR.", LAST_SETTING_ORDER + 1, SettingControlType = typeof(DifficultyAdjustSettingsControl))]
+        public DifficultyBindable ApproachRate { get; } = new DifficultyBindable
         {
             Precision = 0.1f,
             MinValue = 1,
             MaxValue = 10,
-            Default = 5,
-            Value = 5,
+            ExtendedMaxValue = 11,
+            ReadCurrentFromDifficulty = diff => diff.ApproachRate,
         };
 
         [SettingSource("Spicy Patterns", "Adjust the patterns as if Hard Rock is enabled.")]
         public BindableBool HardRockOffsets { get; } = new BindableBool();
 
-        protected override void ApplyLimits(bool extended)
-        {
-            base.ApplyLimits(extended);
-
-            CircleSize.MaxValue = extended ? 11 : 10;
-            ApproachRate.MaxValue = extended ? 11 : 10;
-        }
-
         public override string SettingDescription
         {
             get
@@ -61,20 +53,12 @@ namespace osu.Game.Rulesets.Catch.Mods
             }
         }
 
-        protected override void TransferSettings(BeatmapDifficulty difficulty)
-        {
-            base.TransferSettings(difficulty);
-
-            TransferSetting(CircleSize, difficulty.CircleSize);
-            TransferSetting(ApproachRate, difficulty.ApproachRate);
-        }
-
         protected override void ApplySettings(BeatmapDifficulty difficulty)
         {
             base.ApplySettings(difficulty);
 
-            ApplySetting(CircleSize, cs => difficulty.CircleSize = cs);
-            ApplySetting(ApproachRate, ar => difficulty.ApproachRate = ar);
+            if (CircleSize.Value != null) difficulty.CircleSize = CircleSize.Value.Value;
+            if (ApproachRate.Value != null) difficulty.ApproachRate = ApproachRate.Value.Value;
         }
 
         public void ApplyToBeatmapProcessor(IBeatmapProcessor beatmapProcessor)

osu.Game.Rulesets.Catch/Objects/CatchHitObject.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 Newtonsoft.Json;
 using osu.Framework.Bindables;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
@@ -20,6 +21,11 @@ namespace osu.Game.Rulesets.Catch.Objects
         /// <summary>
         /// The horizontal position of the hit object between 0 and <see cref="CatchPlayfield.WIDTH"/>.
         /// </summary>
+        /// <remarks>
+        /// Only setter is exposed.
+        /// Use <see cref="OriginalX"/> or <see cref="EffectiveX"/> to get the horizontal position.
+        /// </remarks>
+        [JsonIgnore]
         public float X
         {
             set => OriginalXBindable.Value = value;
@@ -34,6 +40,7 @@ namespace osu.Game.Rulesets.Catch.Objects
         /// </summary>
         public float XOffset
         {
+            get => XOffsetBindable.Value;
             set => XOffsetBindable.Value = value;
         }
 
@@ -44,7 +51,11 @@ namespace osu.Game.Rulesets.Catch.Objects
         /// This value is the original <see cref="X"/> value specified in the beatmap, not affected by the beatmap processing.
         /// Use <see cref="EffectiveX"/> for a gameplay.
         /// </remarks>
-        public float OriginalX => OriginalXBindable.Value;
+        public float OriginalX
+        {
+            get => OriginalXBindable.Value;
+            set => OriginalXBindable.Value = value;
+        }
 
         /// <summary>
         /// The effective horizontal position of the hit object between 0 and <see cref="CatchPlayfield.WIDTH"/>.
@@ -53,9 +64,9 @@ namespace osu.Game.Rulesets.Catch.Objects
         /// This value is the original <see cref="X"/> value plus the offset applied by the beatmap processing.
         /// Use <see cref="OriginalX"/> if a value not affected by the offset is desired.
         /// </remarks>
-        public float EffectiveX => OriginalXBindable.Value + XOffsetBindable.Value;
+        public float EffectiveX => OriginalX + XOffset;
 
-        public double TimePreempt = 1000;
+        public double TimePreempt { get; set; } = 1000;
 
         public readonly Bindable<int> IndexInBeatmapBindable = new Bindable<int>();
 

osu.Game.Rulesets.Catch/Objects/JuiceStream.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
+using Newtonsoft.Json;
 using osu.Game.Audio;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
@@ -25,7 +26,10 @@ namespace osu.Game.Rulesets.Catch.Objects
 
         public int RepeatCount { get; set; }
 
+        [JsonIgnore]
         public double Velocity { get; private set; }
+
+        [JsonIgnore]
         public double TickDistance { get; private set; }
 
         /// <summary>
@@ -113,6 +117,7 @@ namespace osu.Game.Rulesets.Catch.Objects
 
         public float EndX => OriginalX + this.CurvePositionAt(1).X;
 
+        [JsonIgnore]
         public double Duration
         {
             get => this.SpanCount() * Path.Distance / Velocity;

osu.Game.Rulesets.Catch/Objects/PalpableCatchHitObject.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
+using Newtonsoft.Json;
 using osu.Framework.Bindables;
 using osu.Game.Rulesets.Objects.Types;
 using osuTK.Graphics;
@@ -33,6 +34,7 @@ namespace osu.Game.Rulesets.Catch.Objects
         /// <summary>
         /// The target fruit if we are to initiate a hyperdash.
         /// </summary>
+        [JsonIgnore]
         public CatchHitObject HyperDashTarget
         {
             get => hyperDashTarget;

osu.Game.Rulesets.Catch/Skinning/CatchSkinConfiguration.cs

@@ -0,0 +1,13 @@
+// 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.
+
+namespace osu.Game.Rulesets.Catch.Skinning
+{
+    public enum CatchSkinConfiguration
+    {
+        /// <summary>
+        /// Whether the contents of the catcher plate should be visually flipped when the catcher direction is changed.
+        /// </summary>
+        FlipCatcherPlate
+    }
+}

osu.Game.Rulesets.Catch/Skinning/Legacy/CatchLegacySkinTransformer.cs

@@ -103,6 +103,19 @@ namespace osu.Game.Rulesets.Catch.Skinning.Legacy
 
                     result.Value = LegacyColourCompatibility.DisallowZeroAlpha(result.Value);
                     return (IBindable<TValue>)result;
+
+                case CatchSkinConfiguration config:
+                    switch (config)
+                    {
+                        case CatchSkinConfiguration.FlipCatcherPlate:
+                            // Don't flip catcher plate contents if the catcher is provided by this legacy skin.
+                            if (GetDrawableComponent(new CatchSkinComponent(CatchSkinComponents.Catcher)) != null)
+                                return (IBindable<TValue>)new Bindable<bool>();
+
+                            break;
+                    }
+
+                    break;
             }
 
             return base.GetConfig<TLookup, TValue>(lookup);

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

@@ -56,11 +56,6 @@ namespace osu.Game.Rulesets.Catch.UI
         /// </summary>
         public double Speed => (Dashing ? 1 : 0.5) * BASE_SPEED * hyperDashModifier;
 
-        /// <summary>
-        /// The amount by which caught fruit should be offset from the plate surface to make them look visually "caught".
-        /// </summary>
-        public const float CAUGHT_FRUIT_VERTICAL_OFFSET = -5;
-
         /// <summary>
         /// The amount by which caught fruit should be scaled down to fit on the plate.
         /// </summary>
@@ -84,8 +79,8 @@ namespace osu.Game.Rulesets.Catch.UI
 
         public CatcherAnimationState CurrentState
         {
-            get => body.AnimationState.Value;
-            private set => body.AnimationState.Value = value;
+            get => Body.AnimationState.Value;
+            private set => Body.AnimationState.Value = value;
         }
 
         /// <summary>
@@ -108,18 +103,22 @@ namespace osu.Game.Rulesets.Catch.UI
             }
         }
 
-        public Direction VisualDirection
-        {
-            get => Scale.X > 0 ? Direction.Right : Direction.Left;
-            set => Scale = new Vector2((value == Direction.Right ? 1 : -1) * Math.Abs(Scale.X), Scale.Y);
-        }
+        /// <summary>
+        /// The currently facing direction.
+        /// </summary>
+        public Direction VisualDirection { get; set; } = Direction.Right;
+
+        /// <summary>
+        /// Whether the contents of the catcher plate should be visually flipped when the catcher direction is changed.
+        /// </summary>
+        private bool flipCatcherPlate;
 
         /// <summary>
         /// Width of the area that can be used to attempt catches during gameplay.
         /// </summary>
         private readonly float catchWidth;
 
-        private readonly SkinnableCatcher body;
+        internal readonly SkinnableCatcher Body;
 
         private Color4 hyperDashColour = DEFAULT_HYPER_DASH_COLOUR;
         private Color4 hyperDashEndGlowColour = DEFAULT_HYPER_DASH_COLOUR;
@@ -157,8 +156,10 @@ namespace osu.Game.Rulesets.Catch.UI
                 {
                     Anchor = Anchor.TopCentre,
                     Origin = Anchor.BottomCentre,
+                    // offset fruit vertically to better place "above" the plate.
+                    Y = -5
                 },
-                body = new SkinnableCatcher(),
+                Body = new SkinnableCatcher(),
                 hitExplosionContainer = new HitExplosionContainer
                 {
                     Anchor = Anchor.TopCentre,
@@ -347,6 +348,8 @@ namespace osu.Game.Rulesets.Catch.UI
             trails.HyperDashTrailsColour = hyperDashColour;
             trails.EndGlowSpritesColour = hyperDashEndGlowColour;
 
+            flipCatcherPlate = skin.GetConfig<CatchSkinConfiguration, bool>(CatchSkinConfiguration.FlipCatcherPlate)?.Value ?? true;
+
             runHyperDashStateTransition(HyperDashing);
         }
 
@@ -354,6 +357,10 @@ namespace osu.Game.Rulesets.Catch.UI
         {
             base.Update();
 
+            var scaleFromDirection = new Vector2((int)VisualDirection, 1);
+            Body.Scale = scaleFromDirection;
+            caughtObjectContainer.Scale = hitExplosionContainer.Scale = flipCatcherPlate ? scaleFromDirection : Vector2.One;
+
             // Correct overshooting.
             if ((hyperDashDirection > 0 && hyperDashTargetPosition < X) ||
                 (hyperDashDirection < 0 && hyperDashTargetPosition > X))
@@ -388,9 +395,6 @@ namespace osu.Game.Rulesets.Catch.UI
             float adjustedRadius = displayRadius * lenience_adjust;
             float checkDistance = MathF.Pow(adjustedRadius, 2);
 
-            // offset fruit vertically to better place "above" the plate.
-            position.Y += CAUGHT_FRUIT_VERTICAL_OFFSET;
-
             while (caughtObjectContainer.Any(f => Vector2Extensions.DistanceSquared(f.Position, position) < checkDistance))
             {
                 position.X += RNG.NextSingle(-adjustedRadius, adjustedRadius);
@@ -465,7 +469,7 @@ namespace osu.Game.Rulesets.Catch.UI
                     break;
 
                 case DroppedObjectAnimation.Explode:
-                    var originalX = droppedObjectTarget.ToSpaceOfOtherDrawable(d.DrawPosition, caughtObjectContainer).X * Scale.X;
+                    float originalX = droppedObjectTarget.ToSpaceOfOtherDrawable(d.DrawPosition, caughtObjectContainer).X * caughtObjectContainer.Scale.X;
                     d.MoveToY(d.Y - 50, 250, Easing.OutSine).Then().MoveToY(d.Y + 50, 500, Easing.InSine);
                     d.MoveToX(d.X + originalX * 6, 1000);
                     d.FadeOut(750);

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

@@ -121,7 +121,7 @@ namespace osu.Game.Rulesets.Catch.UI
             CatcherTrail sprite = trailPool.Get();
 
             sprite.AnimationState = catcher.CurrentState;
-            sprite.Scale = catcher.Scale;
+            sprite.Scale = catcher.Scale * catcher.Body.Scale;
             sprite.Position = catcher.Position;
 
             target.Add(sprite);

osu.Game.Rulesets.Mania.Tests/osu.Game.Rulesets.Mania.Tests.csproj

@@ -4,7 +4,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <PropertyGroup Label="Project">

osu.Game.Rulesets.Osu.Tests/Editor/Checks/CheckTooShortSlidersTest.cs

@@ -0,0 +1,145 @@
+// 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 System.Linq;
+using NUnit.Framework;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu.Edit.Checks;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Tests.Beatmaps;
+using osuTK;
+
+namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
+{
+    [TestFixture]
+    public class CheckTooShortSlidersTest
+    {
+        private CheckTooShortSliders check;
+
+        [SetUp]
+        public void Setup()
+        {
+            check = new CheckTooShortSliders();
+        }
+
+        [Test]
+        public void TestLongSlider()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(100, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertOk(new List<HitObject> { slider });
+        }
+
+        [Test]
+        public void TestShortSlider()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(25, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertOk(new List<HitObject> { slider });
+        }
+
+        [Test]
+        public void TestTooShortSliderExpert()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(10, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertOk(new List<HitObject> { slider }, DifficultyRating.Expert);
+        }
+
+        [Test]
+        public void TestTooShortSlider()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(10, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertTooShort(new List<HitObject> { slider });
+        }
+
+        [Test]
+        public void TestTooShortSliderWithRepeats()
+        {
+            // Would be ok if we looked at the duration, but not if we look at the span duration.
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 2,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(10, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertTooShort(new List<HitObject> { slider });
+        }
+
+        private void assertOk(List<HitObject> hitObjects, DifficultyRating difficultyRating = DifficultyRating.Easy)
+        {
+            Assert.That(check.Run(getContext(hitObjects, difficultyRating)), Is.Empty);
+        }
+
+        private void assertTooShort(List<HitObject> hitObjects, DifficultyRating difficultyRating = DifficultyRating.Easy)
+        {
+            var issues = check.Run(getContext(hitObjects, difficultyRating)).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.First().Template is CheckTooShortSliders.IssueTemplateTooShort);
+        }
+
+        private BeatmapVerifierContext getContext(List<HitObject> hitObjects, DifficultyRating difficultyRating)
+        {
+            var beatmap = new Beatmap<HitObject> { HitObjects = hitObjects };
+
+            return new BeatmapVerifierContext(beatmap, new TestWorkingBeatmap(beatmap), difficultyRating);
+        }
+    }
+}

osu.Game.Rulesets.Osu.Tests/Editor/Checks/CheckTooShortSpinnersTest.cs

@@ -0,0 +1,116 @@
+// 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 System.Linq;
+using NUnit.Framework;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu.Edit.Checks;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Tests.Beatmaps;
+
+namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
+{
+    [TestFixture]
+    public class CheckTooShortSpinnersTest
+    {
+        private CheckTooShortSpinners check;
+        private BeatmapDifficulty difficulty;
+
+        [SetUp]
+        public void Setup()
+        {
+            check = new CheckTooShortSpinners();
+            difficulty = new BeatmapDifficulty();
+        }
+
+        [Test]
+        public void TestLongSpinner()
+        {
+            Spinner spinner = new Spinner { StartTime = 0, Duration = 4000 };
+            spinner.ApplyDefaults(new ControlPointInfo(), difficulty);
+
+            assertOk(new List<HitObject> { spinner }, difficulty);
+        }
+
+        [Test]
+        public void TestShortSpinner()
+        {
+            Spinner spinner = new Spinner { StartTime = 0, Duration = 750 };
+            spinner.ApplyDefaults(new ControlPointInfo(), difficulty);
+
+            assertOk(new List<HitObject> { spinner }, difficulty);
+        }
+
+        [Test]
+        public void TestVeryShortSpinner()
+        {
+            // Spinners at a certain duration only get 1000 points if approached by auto at a certain angle, making it difficult to determine.
+            Spinner spinner = new Spinner { StartTime = 0, Duration = 475 };
+            spinner.ApplyDefaults(new ControlPointInfo(), difficulty);
+
+            assertVeryShort(new List<HitObject> { spinner }, difficulty);
+        }
+
+        [Test]
+        public void TestTooShortSpinner()
+        {
+            Spinner spinner = new Spinner { StartTime = 0, Duration = 400 };
+            spinner.ApplyDefaults(new ControlPointInfo(), difficulty);
+
+            assertTooShort(new List<HitObject> { spinner }, difficulty);
+        }
+
+        [Test]
+        public void TestTooShortSpinnerVaryingOd()
+        {
+            const double duration = 450;
+
+            var difficultyLowOd = new BeatmapDifficulty { OverallDifficulty = 1 };
+            Spinner spinnerLowOd = new Spinner { StartTime = 0, Duration = duration };
+            spinnerLowOd.ApplyDefaults(new ControlPointInfo(), difficultyLowOd);
+
+            var difficultyHighOd = new BeatmapDifficulty { OverallDifficulty = 10 };
+            Spinner spinnerHighOd = new Spinner { StartTime = 0, Duration = duration };
+            spinnerHighOd.ApplyDefaults(new ControlPointInfo(), difficultyHighOd);
+
+            assertOk(new List<HitObject> { spinnerLowOd }, difficultyLowOd);
+            assertTooShort(new List<HitObject> { spinnerHighOd }, difficultyHighOd);
+        }
+
+        private void assertOk(List<HitObject> hitObjects, BeatmapDifficulty beatmapDifficulty)
+        {
+            Assert.That(check.Run(getContext(hitObjects, beatmapDifficulty)), Is.Empty);
+        }
+
+        private void assertVeryShort(List<HitObject> hitObjects, BeatmapDifficulty beatmapDifficulty)
+        {
+            var issues = check.Run(getContext(hitObjects, beatmapDifficulty)).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.First().Template is CheckTooShortSpinners.IssueTemplateVeryShort);
+        }
+
+        private void assertTooShort(List<HitObject> hitObjects, BeatmapDifficulty beatmapDifficulty)
+        {
+            var issues = check.Run(getContext(hitObjects, beatmapDifficulty)).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.First().Template is CheckTooShortSpinners.IssueTemplateTooShort);
+        }
+
+        private BeatmapVerifierContext getContext(List<HitObject> hitObjects, BeatmapDifficulty beatmapDifficulty)
+        {
+            var beatmap = new Beatmap<HitObject>
+            {
+                HitObjects = hitObjects,
+                BeatmapInfo = new BeatmapInfo { BaseDifficulty = beatmapDifficulty }
+            };
+
+            return new BeatmapVerifierContext(beatmap, new TestWorkingBeatmap(beatmap));
+        }
+    }
+}

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

@@ -121,7 +121,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                 {
                     case OsuSkinConfiguration osuLookup:
                         if (osuLookup == OsuSkinConfiguration.CursorCentre)
-                            return SkinUtils.As<TValue>(new BindableBool(false));
+                            return SkinUtils.As<TValue>(new BindableBool());
 
                         break;
                 }

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

@@ -37,11 +37,13 @@ namespace osu.Game.Rulesets.Osu.Tests
         private readonly BindableBool snakingIn = new BindableBool();
         private readonly BindableBool snakingOut = new BindableBool();
 
+        private IBeatmap beatmap;
+
         private const double duration_of_span = 3605;
         private const double fade_in_modifier = -1200;
 
         protected override WorkingBeatmap CreateWorkingBeatmap(IBeatmap beatmap, Storyboard storyboard = null)
-            => new ClockBackedTestWorkingBeatmap(beatmap, storyboard, new FramedClock(new ManualClock { Rate = 1 }), audioManager);
+            => new ClockBackedTestWorkingBeatmap(this.beatmap = beatmap, storyboard, new FramedClock(new ManualClock { Rate = 1 }), audioManager);
 
         [BackgroundDependencyLoader]
         private void load(RulesetConfigCache configCache)
@@ -51,8 +53,16 @@ namespace osu.Game.Rulesets.Osu.Tests
             config.BindWith(OsuRulesetSetting.SnakingOutSliders, snakingOut);
         }
 
+        private Slider slider;
         private DrawableSlider drawableSlider;
 
+        [SetUp]
+        public void Setup() => Schedule(() =>
+        {
+            slider = null;
+            drawableSlider = null;
+        });
+
         [SetUpSteps]
         public override void SetUpSteps()
         {
@@ -67,21 +77,19 @@ namespace osu.Game.Rulesets.Osu.Tests
             base.SetUpSteps();
             AddUntilStep("wait for track to start running", () => Beatmap.Value.Track.IsRunning);
 
-            double startTime = hitObjects[sliderIndex].StartTime;
-            addSeekStep(startTime);
-            retrieveDrawableSlider((Slider)hitObjects[sliderIndex]);
+            retrieveSlider(sliderIndex);
             setSnaking(true);
 
-            ensureSnakingIn(startTime + fade_in_modifier);
+            addEnsureSnakingInSteps(() => slider.StartTime + fade_in_modifier);
 
             for (int i = 0; i < sliderIndex; i++)
             {
                 // non-final repeats should not snake out
-                ensureNoSnakingOut(startTime, i);
+                addEnsureNoSnakingOutStep(() => slider.StartTime, i);
             }
 
             // final repeat should snake out
-            ensureSnakingOut(startTime, sliderIndex);
+            addEnsureSnakingOutSteps(() => slider.StartTime, sliderIndex);
         }
 
         [TestCase(0)]
@@ -93,17 +101,15 @@ namespace osu.Game.Rulesets.Osu.Tests
             base.SetUpSteps();
             AddUntilStep("wait for track to start running", () => Beatmap.Value.Track.IsRunning);
 
-            double startTime = hitObjects[sliderIndex].StartTime;
-            addSeekStep(startTime);
-            retrieveDrawableSlider((Slider)hitObjects[sliderIndex]);
+            retrieveSlider(sliderIndex);
             setSnaking(false);
 
-            ensureNoSnakingIn(startTime + fade_in_modifier);
+            addEnsureNoSnakingInSteps(() => slider.StartTime + fade_in_modifier);
 
             for (int i = 0; i <= sliderIndex; i++)
             {
                 // no snaking out ever, including final repeat
-                ensureNoSnakingOut(startTime, i);
+                addEnsureNoSnakingOutStep(() => slider.StartTime, i);
             }
         }
 
@@ -116,7 +122,7 @@ namespace osu.Game.Rulesets.Osu.Tests
 
             // repeat might have a chance to update its position depending on where in the frame its hit,
             // so some leniency is allowed here instead of checking strict equality
-            checkPositionChange(16600, sliderRepeat, positionAlmostSame);
+            addCheckPositionChangeSteps(() => 16600, getSliderRepeat, positionAlmostSame);
         }
 
         [Test]
@@ -126,38 +132,41 @@ namespace osu.Game.Rulesets.Osu.Tests
             setSnaking(true);
             base.SetUpSteps();
 
-            checkPositionChange(16600, sliderRepeat, positionDecreased);
+            addCheckPositionChangeSteps(() => 16600, getSliderRepeat, positionDecreased);
         }
 
-        private void retrieveDrawableSlider(Slider slider) => AddUntilStep($"retrieve slider @ {slider.StartTime}", () =>
-            (drawableSlider = (DrawableSlider)Player.DrawableRuleset.Playfield.AllHitObjects.SingleOrDefault(d => d.HitObject == slider)) != null);
-
-        private void ensureSnakingIn(double startTime) => checkPositionChange(startTime, sliderEnd, positionIncreased);
-        private void ensureNoSnakingIn(double startTime) => checkPositionChange(startTime, sliderEnd, positionRemainsSame);
-
-        private void ensureSnakingOut(double startTime, int repeatIndex)
+        private void retrieveSlider(int index)
         {
-            var repeatTime = timeAtRepeat(startTime, repeatIndex);
+            AddStep("retrieve slider at index", () => slider = (Slider)beatmap.HitObjects[index]);
+            addSeekStep(() => slider);
+            AddUntilStep("retrieve drawable slider", () =>
+                (drawableSlider = (DrawableSlider)Player.DrawableRuleset.Playfield.AllHitObjects.SingleOrDefault(d => d.HitObject == slider)) != null);
+        }
 
+        private void addEnsureSnakingInSteps(Func<double> startTime) => addCheckPositionChangeSteps(startTime, getSliderEnd, positionIncreased);
+        private void addEnsureNoSnakingInSteps(Func<double> startTime) => addCheckPositionChangeSteps(startTime, getSliderEnd, positionRemainsSame);
+
+        private void addEnsureSnakingOutSteps(Func<double> startTime, int repeatIndex)
+        {
             if (repeatIndex % 2 == 0)
-                checkPositionChange(repeatTime, sliderStart, positionIncreased);
+                addCheckPositionChangeSteps(timeAtRepeat(startTime, repeatIndex), getSliderStart, positionIncreased);
             else
-                checkPositionChange(repeatTime, sliderEnd, positionDecreased);
+                addCheckPositionChangeSteps(timeAtRepeat(startTime, repeatIndex), getSliderEnd, positionDecreased);
         }
 
-        private void ensureNoSnakingOut(double startTime, int repeatIndex) =>
-            checkPositionChange(timeAtRepeat(startTime, repeatIndex), positionAtRepeat(repeatIndex), positionRemainsSame);
+        private void addEnsureNoSnakingOutStep(Func<double> startTime, int repeatIndex)
+            => addCheckPositionChangeSteps(timeAtRepeat(startTime, repeatIndex), positionAtRepeat(repeatIndex), positionRemainsSame);
 
-        private double timeAtRepeat(double startTime, int repeatIndex) => startTime + 100 + duration_of_span * repeatIndex;
-        private Func<Vector2> positionAtRepeat(int repeatIndex) => repeatIndex % 2 == 0 ? (Func<Vector2>)sliderStart : sliderEnd;
+        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 List<Vector2> sliderCurve => ((PlaySliderBody)drawableSlider.Body.Drawable).CurrentCurve;
-        private Vector2 sliderStart() => sliderCurve.First();
-        private Vector2 sliderEnd() => sliderCurve.Last();
+        private List<Vector2> getSliderCurve() => ((PlaySliderBody)drawableSlider.Body.Drawable).CurrentCurve;
+        private Vector2 getSliderStart() => getSliderCurve().First();
+        private Vector2 getSliderEnd() => getSliderCurve().Last();
 
-        private Vector2 sliderRepeat()
+        private Vector2 getSliderRepeat()
         {
-            var drawable = Player.DrawableRuleset.Playfield.AllHitObjects.SingleOrDefault(d => d.HitObject == hitObjects[1]);
+            var drawable = Player.DrawableRuleset.Playfield.AllHitObjects.SingleOrDefault(d => d.HitObject == beatmap.HitObjects[1]);
             var repeat = drawable.ChildrenOfType<Container<DrawableSliderRepeat>>().First().Children.First();
             return repeat.Position;
         }
@@ -167,7 +176,7 @@ namespace osu.Game.Rulesets.Osu.Tests
         private bool positionDecreased(Vector2 previous, Vector2 current) => current.X < previous.X && current.Y < previous.Y;
         private bool positionAlmostSame(Vector2 previous, Vector2 current) => Precision.AlmostEquals(previous, current, 1);
 
-        private void checkPositionChange(double startTime, Func<Vector2> positionToCheck, Func<Vector2, Vector2, bool> positionAssertion)
+        private void addCheckPositionChangeSteps(Func<double> startTime, Func<Vector2> positionToCheck, Func<Vector2, Vector2, bool> positionAssertion)
         {
             Vector2 previousPosition = Vector2.Zero;
 
@@ -176,7 +185,7 @@ namespace osu.Game.Rulesets.Osu.Tests
 
             addSeekStep(startTime);
             AddStep($"save {positionDescription} position", () => previousPosition = positionToCheck.Invoke());
-            addSeekStep(startTime + 100);
+            addSeekStep(() => startTime() + 100);
             AddAssert($"{positionDescription} {assertionDescription}", () =>
             {
                 var currentPosition = positionToCheck.Invoke();
@@ -193,19 +202,21 @@ namespace osu.Game.Rulesets.Osu.Tests
             });
         }
 
-        private void addSeekStep(double time)
+        private void addSeekStep(Func<Slider> slider)
         {
-            AddStep($"seek to {time}", () => Player.GameplayClockContainer.Seek(time));
-
-            AddUntilStep("wait for seek to finish", () => Precision.AlmostEquals(time, Player.DrawableRuleset.FrameStableClock.CurrentTime, 100));
+            AddStep("seek to slider", () => Player.GameplayClockContainer.Seek(slider().StartTime));
+            AddUntilStep("wait for seek to finish", () => Precision.AlmostEquals(slider().StartTime, Player.DrawableRuleset.FrameStableClock.CurrentTime, 100));
         }
 
-        protected override IBeatmap CreateBeatmap(RulesetInfo ruleset) => new Beatmap
+        private void addSeekStep(Func<double> time)
         {
-            HitObjects = hitObjects
-        };
+            AddStep("seek to time", () => Player.GameplayClockContainer.Seek(time()));
+            AddUntilStep("wait for seek to finish", () => Precision.AlmostEquals(time(), Player.DrawableRuleset.FrameStableClock.CurrentTime, 100));
+        }
 
-        private readonly List<HitObject> hitObjects = new List<HitObject>
+        protected override IBeatmap CreateBeatmap(RulesetInfo ruleset) => new Beatmap { HitObjects = createHitObjects() };
+
+        private static List<HitObject> createHitObjects() => new List<HitObject>
         {
             new Slider
             {

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

@@ -5,7 +5,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="Moq" Version="4.16.1" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <PropertyGroup Label="Project">

osu.Game.Rulesets.Osu/Edit/Checks/CheckTooShortSliders.cs

@@ -0,0 +1,48 @@
+// 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 osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Edit.Checks.Components;
+using osu.Game.Rulesets.Osu.Objects;
+
+namespace osu.Game.Rulesets.Osu.Edit.Checks
+{
+    public class CheckTooShortSliders : ICheck
+    {
+        /// <summary>
+        /// The shortest acceptable duration between the head and tail of the slider (so ignoring repeats).
+        /// </summary>
+        private const double span_duration_threshold = 125; // 240 BPM 1/2
+
+        public CheckMetadata Metadata { get; } = new CheckMetadata(CheckCategory.Spread, "Too short sliders");
+
+        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
+        {
+            new IssueTemplateTooShort(this)
+        };
+
+        public IEnumerable<Issue> Run(BeatmapVerifierContext context)
+        {
+            if (context.InterpretedDifficulty > DifficultyRating.Easy)
+                yield break;
+
+            foreach (var hitObject in context.Beatmap.HitObjects)
+            {
+                if (hitObject is Slider slider && slider.SpanDuration < span_duration_threshold)
+                    yield return new IssueTemplateTooShort(this).Create(slider);
+            }
+        }
+
+        public class IssueTemplateTooShort : IssueTemplate
+        {
+            public IssueTemplateTooShort(ICheck check)
+                : base(check, IssueType.Problem, "This slider is too short ({0:0} ms), expected at least {1:0} ms.")
+            {
+            }
+
+            public Issue Create(Slider slider) => new Issue(slider, this, slider.SpanDuration, span_duration_threshold);
+        }
+    }
+}

osu.Game.Rulesets.Osu/Edit/Checks/CheckTooShortSpinners.cs

@@ -0,0 +1,61 @@
+// 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 osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Edit.Checks.Components;
+using osu.Game.Rulesets.Osu.Objects;
+
+namespace osu.Game.Rulesets.Osu.Edit.Checks
+{
+    public class CheckTooShortSpinners : ICheck
+    {
+        public CheckMetadata Metadata { get; } = new CheckMetadata(CheckCategory.Spread, "Too short spinners");
+
+        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
+        {
+            new IssueTemplateTooShort(this)
+        };
+
+        public IEnumerable<Issue> Run(BeatmapVerifierContext context)
+        {
+            double od = context.Beatmap.BeatmapInfo.BaseDifficulty.OverallDifficulty;
+
+            // These are meant to reflect the duration necessary for auto to score at least 1000 points on the spinner.
+            // It's difficult to eliminate warnings here, as auto achieving 1000 points depends on the approach angle on some spinners.
+            double warningThreshold = 500 + (od < 5 ? (5 - od) * -21.8 : (od - 5) * 20); // Anything above this is always ok.
+            double problemThreshold = 450 + (od < 5 ? (5 - od) * -17 : (od - 5) * 17); // Anything below this is never ok.
+
+            foreach (var hitObject in context.Beatmap.HitObjects)
+            {
+                if (!(hitObject is Spinner spinner))
+                    continue;
+
+                if (spinner.Duration < problemThreshold)
+                    yield return new IssueTemplateTooShort(this).Create(spinner);
+                else if (spinner.Duration < warningThreshold)
+                    yield return new IssueTemplateVeryShort(this).Create(spinner);
+            }
+        }
+
+        public class IssueTemplateTooShort : IssueTemplate
+        {
+            public IssueTemplateTooShort(ICheck check)
+                : base(check, IssueType.Problem, "This spinner is too short. Auto cannot achieve 1000 points on this.")
+            {
+            }
+
+            public Issue Create(Spinner spinner) => new Issue(spinner, this);
+        }
+
+        public class IssueTemplateVeryShort : IssueTemplate
+        {
+            public IssueTemplateVeryShort(ICheck check)
+                : base(check, IssueType.Warning, "This spinner may be too short. Ensure auto can achieve 1000 points on this.")
+            {
+            }
+
+            public Issue Create(Spinner spinner) => new Issue(spinner, this);
+        }
+    }
+}

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

@@ -15,10 +15,12 @@ namespace osu.Game.Rulesets.Osu.Edit
         {
             // Compose
             new CheckOffscreenObjects(),
+            new CheckTooShortSpinners(),
 
             // Spread
             new CheckTimeDistanceEquality(),
-            new CheckLowDiffOverlaps()
+            new CheckLowDiffOverlaps(),
+            new CheckTooShortSliders(),
         };
 
         public IEnumerable<Issue> Run(BeatmapVerifierContext context)

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

@@ -0,0 +1,16 @@
+// 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.
+
+namespace osu.Game.Rulesets.Osu.Mods
+{
+    /// <summary>
+    /// Marker interface for any mod which completely hides the approach circles.
+    /// Used for incompatibility with <see cref="IRequiresApproachCircles"/>.
+    /// </summary>
+    /// <remarks>
+    /// Note that this is only a marker interface for incompatibility purposes, it does not change any gameplay behaviour.
+    /// </remarks>
+    public interface IHidesApproachCircles
+    {
+    }
+}

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

@@ -1,12 +0,0 @@
-// 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.
-
-namespace osu.Game.Rulesets.Osu.Mods
-{
-    /// <summary>
-    /// Any mod which affects the animation or visibility of approach circles. Should be used for incompatibility purposes.
-    /// </summary>
-    public interface IMutateApproachCircles
-    {
-    }
-}

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

@@ -0,0 +1,16 @@
+// 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.
+
+namespace osu.Game.Rulesets.Osu.Mods
+{
+    /// <summary>
+    /// Marker interface for any mod which requires the approach circles to be visible.
+    /// Used for incompatibility with <see cref="IHidesApproachCircles"/>.
+    /// </summary>
+    /// <remarks>
+    /// Note that this is only a marker interface for incompatibility purposes, it does not change any gameplay behaviour.
+    /// </remarks>
+    public interface IRequiresApproachCircles
+    {
+    }
+}

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

@@ -12,7 +12,7 @@ using osu.Game.Rulesets.Osu.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModApproachDifferent : Mod, IApplicableToDrawableHitObject, IMutateApproachCircles
+    public class OsuModApproachDifferent : Mod, IApplicableToDrawableHitObject, IRequiresApproachCircles
     {
         public override string Name => "Approach Different";
         public override string Acronym => "AD";
@@ -20,7 +20,7 @@ namespace osu.Game.Rulesets.Osu.Mods
         public override double ScoreMultiplier => 1;
         public override IconUsage? Icon { get; } = FontAwesome.Regular.Circle;
 
-        public override Type[] IncompatibleMods => new[] { typeof(IMutateApproachCircles) };
+        public override Type[] IncompatibleMods => new[] { typeof(IHidesApproachCircles) };
 
         [SettingSource("Initial size", "Change the initial size of the approach circle, relative to hit circles.", 0)]
         public BindableFloat Scale { get; } = new BindableFloat(4)

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

@@ -158,17 +158,17 @@ namespace osu.Game.Rulesets.Osu.Mods
                 var firstObj = beatmap.HitObjects[0];
                 var startDelay = firstObj.StartTime - firstObj.TimePreempt;
 
-                using (BeginAbsoluteSequence(startDelay + break_close_late, true))
+                using (BeginAbsoluteSequence(startDelay + break_close_late))
                     leaveBreak();
 
                 foreach (var breakInfo in beatmap.Breaks)
                 {
                     if (breakInfo.HasEffect)
                     {
-                        using (BeginAbsoluteSequence(breakInfo.StartTime - break_open_early, true))
+                        using (BeginAbsoluteSequence(breakInfo.StartTime - break_open_early))
                         {
                             enterBreak();
-                            using (BeginDelayedSequence(breakInfo.Duration + break_open_early + break_close_late, true))
+                            using (BeginDelayedSequence(breakInfo.Duration + break_open_early + break_close_late))
                                 leaveBreak();
                         }
                     }

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

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Linq;
-using osu.Framework.Bindables;
 using osu.Game.Beatmaps;
 using osu.Game.Configuration;
 using osu.Game.Rulesets.Mods;
@@ -11,34 +10,26 @@ namespace osu.Game.Rulesets.Osu.Mods
 {
     public class OsuModDifficultyAdjust : ModDifficultyAdjust
     {
-        [SettingSource("Circle Size", "Override a beatmap's set CS.", FIRST_SETTING_ORDER - 1)]
-        public BindableNumber<float> CircleSize { get; } = new BindableFloatWithLimitExtension
+        [SettingSource("Circle Size", "Override a beatmap's set CS.", FIRST_SETTING_ORDER - 1, SettingControlType = typeof(DifficultyAdjustSettingsControl))]
+        public DifficultyBindable CircleSize { get; } = new DifficultyBindable
         {
             Precision = 0.1f,
             MinValue = 0,
             MaxValue = 10,
-            Default = 5,
-            Value = 5,
+            ExtendedMaxValue = 11,
+            ReadCurrentFromDifficulty = diff => diff.CircleSize,
         };
 
-        [SettingSource("Approach Rate", "Override a beatmap's set AR.", LAST_SETTING_ORDER + 1)]
-        public BindableNumber<float> ApproachRate { get; } = new BindableFloatWithLimitExtension
+        [SettingSource("Approach Rate", "Override a beatmap's set AR.", LAST_SETTING_ORDER + 1, SettingControlType = typeof(DifficultyAdjustSettingsControl))]
+        public DifficultyBindable ApproachRate { get; } = new DifficultyBindable
         {
             Precision = 0.1f,
             MinValue = 0,
             MaxValue = 10,
-            Default = 5,
-            Value = 5,
+            ExtendedMaxValue = 11,
+            ReadCurrentFromDifficulty = diff => diff.ApproachRate,
         };
 
-        protected override void ApplyLimits(bool extended)
-        {
-            base.ApplyLimits(extended);
-
-            CircleSize.MaxValue = extended ? 11 : 10;
-            ApproachRate.MaxValue = extended ? 11 : 10;
-        }
-
         public override string SettingDescription
         {
             get
@@ -55,20 +46,12 @@ namespace osu.Game.Rulesets.Osu.Mods
             }
         }
 
-        protected override void TransferSettings(BeatmapDifficulty difficulty)
-        {
-            base.TransferSettings(difficulty);
-
-            TransferSetting(CircleSize, difficulty.CircleSize);
-            TransferSetting(ApproachRate, difficulty.ApproachRate);
-        }
-
         protected override void ApplySettings(BeatmapDifficulty difficulty)
         {
             base.ApplySettings(difficulty);
 
-            ApplySetting(CircleSize, cs => difficulty.CircleSize = cs);
-            ApplySetting(ApproachRate, ar => difficulty.ApproachRate = ar);
+            if (CircleSize.Value != null) difficulty.CircleSize = CircleSize.Value.Value;
+            if (ApproachRate.Value != null) difficulty.ApproachRate = ApproachRate.Value.Value;
         }
     }
 }

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

@@ -15,12 +15,12 @@ using osu.Game.Rulesets.Osu.Skinning;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModHidden : ModHidden, IMutateApproachCircles
+    public class OsuModHidden : ModHidden, IHidesApproachCircles
     {
         public override string Description => @"Play with no approach circles and fading circles/sliders.";
         public override double ScoreMultiplier => 1.06;
 
-        public override Type[] IncompatibleMods => new[] { typeof(IMutateApproachCircles) };
+        public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles), typeof(OsuModSpinIn) };
 
         private const double fade_in_duration_multiplier = 0.4;
         private const double fade_out_duration_multiplier = 0.3;

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

@@ -14,7 +14,7 @@ namespace osu.Game.Rulesets.Osu.Mods
     /// <summary>
     /// Adjusts the size of hit objects during their fade in animation.
     /// </summary>
-    public abstract class OsuModObjectScaleTween : ModWithVisibilityAdjustment, IMutateApproachCircles
+    public abstract class OsuModObjectScaleTween : ModWithVisibilityAdjustment, IHidesApproachCircles
     {
         public override ModType Type => ModType.Fun;
 
@@ -24,7 +24,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 
         protected virtual float EndScale => 1;
 
-        public override Type[] IncompatibleMods => new[] { typeof(IMutateApproachCircles) };
+        public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles), typeof(OsuModSpinIn) };
 
         protected override void ApplyIncreasedVisibilityState(DrawableHitObject hitObject, ArmedState state)
         {

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

@@ -12,7 +12,7 @@ using osuTK;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModSpinIn : ModWithVisibilityAdjustment, IMutateApproachCircles
+    public class OsuModSpinIn : ModWithVisibilityAdjustment, IHidesApproachCircles
     {
         public override string Name => "Spin In";
         public override string Acronym => "SI";
@@ -21,8 +21,9 @@ namespace osu.Game.Rulesets.Osu.Mods
         public override string Description => "Circles spin in. No approach circles.";
         public override double ScoreMultiplier => 1;
 
-        // todo: this mod should be able to be compatible with hidden with a bit of further implementation.
-        public override Type[] IncompatibleMods => new[] { typeof(IMutateApproachCircles) };
+        // todo: this mod needs to be incompatible with "hidden" due to forcing the circle to remain opaque,
+        // further implementation will be required for supporting that.
+        public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles), typeof(OsuModObjectScaleTween), typeof(OsuModHidden) };
 
         private const int rotate_offset = 360;
         private const float rotate_starting_width = 2;
@@ -43,7 +44,7 @@ namespace osu.Game.Rulesets.Osu.Mods
             switch (drawable)
             {
                 case DrawableHitCircle circle:
-                    using (circle.BeginAbsoluteSequence(h.StartTime - h.TimePreempt, true))
+                    using (circle.BeginAbsoluteSequence(h.StartTime - h.TimePreempt))
                     {
                         circle.ApproachCircle.Hide();
 

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

@@ -11,7 +11,7 @@ using osu.Game.Rulesets.Osu.Skinning.Default;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModTraceable : ModWithVisibilityAdjustment, IMutateApproachCircles
+    public class OsuModTraceable : ModWithVisibilityAdjustment, IRequiresApproachCircles
     {
         public override string Name => "Traceable";
         public override string Acronym => "TC";
@@ -19,7 +19,7 @@ namespace osu.Game.Rulesets.Osu.Mods
         public override string Description => "Put your faith in the approach circles...";
         public override double ScoreMultiplier => 1;
 
-        public override Type[] IncompatibleMods => new[] { typeof(IMutateApproachCircles) };
+        public override Type[] IncompatibleMods => new[] { typeof(IHidesApproachCircles) };
 
         protected override void ApplyIncreasedVisibilityState(DrawableHitObject hitObject, ArmedState state)
         {
@@ -60,7 +60,7 @@ namespace osu.Game.Rulesets.Osu.Mods
         private void applyCirclePieceState(DrawableOsuHitObject hitObject, IDrawable hitCircle = null)
         {
             var h = hitObject.HitObject;
-            using (hitObject.BeginAbsoluteSequence(h.StartTime - h.TimePreempt, true))
+            using (hitObject.BeginAbsoluteSequence(h.StartTime - h.TimePreempt))
                 (hitCircle ?? hitObject).Hide();
         }
 

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

@@ -50,7 +50,7 @@ namespace osu.Game.Rulesets.Osu.Mods
                     double appearTime = hitObject.StartTime - hitObject.TimePreempt - 1;
                     double moveDuration = hitObject.TimePreempt + 1;
 
-                    using (drawable.BeginAbsoluteSequence(appearTime, true))
+                    using (drawable.BeginAbsoluteSequence(appearTime))
                     {
                         drawable
                             .MoveToOffset(appearOffset)

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

@@ -53,7 +53,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 
             for (int i = 0; i < amountWiggles; i++)
             {
-                using (drawable.BeginAbsoluteSequence(osuObject.StartTime - osuObject.TimePreempt + i * wiggle_duration, true))
+                using (drawable.BeginAbsoluteSequence(osuObject.StartTime - osuObject.TimePreempt + i * wiggle_duration))
                     wiggle();
             }
 
@@ -65,7 +65,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 
             for (int i = 0; i < amountWiggles; i++)
             {
-                using (drawable.BeginAbsoluteSequence(osuObject.StartTime + i * wiggle_duration, true))
+                using (drawable.BeginAbsoluteSequence(osuObject.StartTime + i * wiggle_duration))
                     wiggle();
             }
         }

osu.Game.Rulesets.Osu/Replays/OsuAutoGenerator.cs

@@ -233,35 +233,43 @@ namespace osu.Game.Rulesets.Osu.Replays
 
             // Wait until Auto could "see and react" to the next note.
             double waitTime = h.StartTime - Math.Max(0.0, h.TimePreempt - getReactionTime(h.StartTime - h.TimePreempt));
+            bool hasWaited = false;
 
             if (waitTime > lastFrame.Time)
             {
                 lastFrame = new OsuReplayFrame(waitTime, lastFrame.Position) { Actions = lastFrame.Actions };
+                hasWaited = true;
                 AddFrameToReplay(lastFrame);
             }
 
-            Vector2 lastPosition = lastFrame.Position;
-
             double timeDifference = ApplyModsToTimeDelta(lastFrame.Time, h.StartTime);
+            OsuReplayFrame lastLastFrame = Frames.Count >= 2 ? (OsuReplayFrame)Frames[^2] : null;
 
-            // Only "snap" to hitcircles if they are far enough apart. As the time between hitcircles gets shorter the snapping threshold goes up.
-            if (timeDifference > 0 && // Sanity checks
-                ((lastPosition - targetPos).Length > h.Radius * (1.5 + 100.0 / timeDifference) || // Either the distance is big enough
-                 timeDifference >= 266)) // ... or the beats are slow enough to tap anyway.
+            if (timeDifference > 0)
             {
-                // Perform eased movement
+                // If the last frame is a key-up frame and there has been no wait period, adjust the last frame's position such that it begins eased movement instantaneously.
+                if (lastLastFrame != null && lastFrame is OsuKeyUpReplayFrame && !hasWaited)
+                {
+                    // [lastLastFrame] ... [lastFrame] ... [current frame]
+                    // We want to find the cursor position at lastFrame, so interpolate between lastLastFrame and the new target position.
+                    lastFrame.Position = Interpolation.ValueAt(lastFrame.Time, lastFrame.Position, targetPos, lastLastFrame.Time, h.StartTime, easing);
+                }
+
+                Vector2 lastPosition = lastFrame.Position;
+
+                // Perform the rest of the eased movement until the target position is reached.
                 for (double time = lastFrame.Time + GetFrameDelay(lastFrame.Time); time < h.StartTime; time += GetFrameDelay(time))
                 {
                     Vector2 currentPosition = Interpolation.ValueAt(time, lastPosition, targetPos, lastFrame.Time, h.StartTime, easing);
                     AddFrameToReplay(new OsuReplayFrame((int)time, new Vector2(currentPosition.X, currentPosition.Y)) { Actions = lastFrame.Actions });
                 }
+            }
 
-                buttonIndex = 0;
-            }
-            else
-            {
+            // Start alternating once the time separation is too small (faster than ~225BPM).
+            if (timeDifference > 0 && timeDifference < 266)
                 buttonIndex++;
-            }
+            else
+                buttonIndex = 0;
         }
 
         /// <summary>
@@ -284,7 +292,7 @@ namespace osu.Game.Rulesets.Osu.Replays
             // TODO: Why do we delay 1 ms if the object is a spinner? There already is KEY_UP_DELAY from hEndTime.
             double hEndTime = h.GetEndTime() + KEY_UP_DELAY;
             int endDelay = h is Spinner ? 1 : 0;
-            var endFrame = new OsuReplayFrame(hEndTime + endDelay, new Vector2(h.StackedEndPosition.X, h.StackedEndPosition.Y));
+            var endFrame = new OsuKeyUpReplayFrame(hEndTime + endDelay, new Vector2(h.StackedEndPosition.X, h.StackedEndPosition.Y));
 
             // Decrement because we want the previous frame, not the next one
             int index = FindInsertionIndex(startFrame) - 1;
@@ -381,5 +389,13 @@ namespace osu.Game.Rulesets.Osu.Replays
         }
 
         #endregion
+
+        private class OsuKeyUpReplayFrame : OsuReplayFrame
+        {
+            public OsuKeyUpReplayFrame(double time, Vector2 position)
+                : base(time, position)
+            {
+            }
+        }
     }
 }

osu.Game.Rulesets.Osu/Skinning/Default/DefaultSpinnerDisc.cs

@@ -130,18 +130,18 @@ namespace osu.Game.Rulesets.Osu.Skinning.Default
 
             Spinner spinner = drawableSpinner.HitObject;
 
-            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt, true))
+            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt))
             {
                 this.ScaleTo(initial_scale);
                 this.RotateTo(0);
 
-                using (BeginDelayedSequence(spinner.TimePreempt / 2, true))
+                using (BeginDelayedSequence(spinner.TimePreempt / 2))
                 {
                     // constant ambient rotation to give the spinner "spinning" character.
                     this.RotateTo((float)(25 * spinner.Duration / 2000), spinner.TimePreempt + spinner.Duration);
                 }
 
-                using (BeginDelayedSequence(spinner.TimePreempt + spinner.Duration + drawableHitObject.Result.TimeOffset, true))
+                using (BeginDelayedSequence(spinner.TimePreempt + spinner.Duration + drawableHitObject.Result.TimeOffset))
                 {
                     switch (state)
                     {
@@ -157,17 +157,17 @@ namespace osu.Game.Rulesets.Osu.Skinning.Default
                 }
             }
 
-            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt, true))
+            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt))
             {
                 centre.ScaleTo(0);
                 mainContainer.ScaleTo(0);
 
-                using (BeginDelayedSequence(spinner.TimePreempt / 2, true))
+                using (BeginDelayedSequence(spinner.TimePreempt / 2))
                 {
                     centre.ScaleTo(0.3f, spinner.TimePreempt / 4, Easing.OutQuint);
                     mainContainer.ScaleTo(0.2f, spinner.TimePreempt / 4, Easing.OutQuint);
 
-                    using (BeginDelayedSequence(spinner.TimePreempt / 2, true))
+                    using (BeginDelayedSequence(spinner.TimePreempt / 2))
                     {
                         centre.ScaleTo(0.5f, spinner.TimePreempt / 2, Easing.OutQuint);
                         mainContainer.ScaleTo(1, spinner.TimePreempt / 2, Easing.OutQuint);
@@ -176,7 +176,7 @@ namespace osu.Game.Rulesets.Osu.Skinning.Default
             }
 
             // transforms we have from completing the spinner will be rolled back, so reapply immediately.
-            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt, true))
+            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt))
                 updateComplete(state == ArmedState.Hit, 0);
         }
 

osu.Game.Rulesets.Osu/Skinning/Default/SliderBall.cs

@@ -86,6 +86,7 @@ namespace osu.Game.Rulesets.Osu.Skinning.Default
         public override void ApplyTransformsAt(double time, bool propagateChildren = false)
         {
             // For the same reasons as above w.r.t rewinding, we shouldn't propagate to children here either.
+            // ReSharper disable once RedundantArgumentDefaultValue - removing the "redundant" default value triggers BaseMethodCallWithDefaultParameter
             base.ApplyTransformsAt(time, false);
         }
 

osu.Game.Rulesets.Osu/Skinning/Legacy/LegacyNewStyleSpinner.cs

@@ -100,17 +100,17 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
                 case DrawableSpinner d:
                     Spinner spinner = d.HitObject;
 
-                    using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt, true))
+                    using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt))
                         this.FadeOut();
 
-                    using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimeFadeIn / 2, true))
+                    using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimeFadeIn / 2))
                         this.FadeInFromZero(spinner.TimeFadeIn / 2);
 
-                    using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt, true))
+                    using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt))
                     {
                         fixedMiddle.FadeColour(Color4.White);
 
-                        using (BeginDelayedSequence(spinner.TimePreempt, true))
+                        using (BeginDelayedSequence(spinner.TimePreempt))
                             fixedMiddle.FadeColour(Color4.Red, spinner.Duration);
                     }
 

osu.Game.Rulesets.Osu/Skinning/Legacy/LegacyOldStyleSpinner.cs

@@ -89,10 +89,10 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
 
             Spinner spinner = d.HitObject;
 
-            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt, true))
+            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimePreempt))
                 this.FadeOut();
 
-            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimeFadeIn / 2, true))
+            using (BeginAbsoluteSequence(spinner.StartTime - spinner.TimeFadeIn / 2))
                 this.FadeInFromZero(spinner.TimeFadeIn / 2);
         }
 

osu.Game.Rulesets.Osu/Skinning/Legacy/LegacySpinner.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
 
         /// <remarks>
         /// All constants are in osu!stable's gamefield space, which is shifted 16px downwards.
-        /// This offset is negated in both osu!stable and osu!lazer to bring all constants into window-space.
+        /// This offset is negated to bring all constants into window-space.
         /// Note: SPINNER_Y_CENTRE + SPINNER_TOP_OFFSET - Position.Y = 240 (=480/2, or half the window-space in osu!stable)
         /// </remarks>
         protected const float SPINNER_TOP_OFFSET = 45f - 16f;
@@ -140,7 +140,7 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
             {
                 double startTime = Math.Min(Time.Current, DrawableSpinner.HitStateUpdateTime - 400);
 
-                using (BeginAbsoluteSequence(startTime, true))
+                using (BeginAbsoluteSequence(startTime))
                 {
                     clear.FadeInFromZero(400, Easing.Out);
 
@@ -150,7 +150,7 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
                 }
 
                 const double fade_out_duration = 50;
-                using (BeginAbsoluteSequence(DrawableSpinner.HitStateUpdateTime - fade_out_duration, true))
+                using (BeginAbsoluteSequence(DrawableSpinner.HitStateUpdateTime - fade_out_duration))
                     clear.FadeOut(fade_out_duration);
             }
             else
@@ -182,14 +182,14 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
 
                     double spinFadeOutLength = Math.Min(400, d.HitObject.Duration);
 
-                    using (BeginAbsoluteSequence(drawableHitObject.HitStateUpdateTime - spinFadeOutLength, true))
+                    using (BeginAbsoluteSequence(drawableHitObject.HitStateUpdateTime - spinFadeOutLength))
                         spin.FadeOutFromOne(spinFadeOutLength);
                     break;
 
                 case DrawableSpinnerTick d:
                     if (state == ArmedState.Hit)
                     {
-                        using (BeginAbsoluteSequence(d.HitStateUpdateTime, true))
+                        using (BeginAbsoluteSequence(d.HitStateUpdateTime))
                             spin.FadeOut(300);
                     }
 

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

@@ -4,7 +4,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
   </ItemGroup>
   <PropertyGroup Label="Project">

osu.Game.Rulesets.Taiko/Mods/TaikoModDifficultyAdjust.cs

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Linq;
-using osu.Framework.Bindables;
 using osu.Game.Beatmaps;
 using osu.Game.Configuration;
 using osu.Game.Rulesets.Mods;
@@ -11,14 +10,13 @@ namespace osu.Game.Rulesets.Taiko.Mods
 {
     public class TaikoModDifficultyAdjust : ModDifficultyAdjust
     {
-        [SettingSource("Scroll Speed", "Adjust a beatmap's set scroll speed", LAST_SETTING_ORDER + 1)]
-        public BindableNumber<float> ScrollSpeed { get; } = new BindableFloat
+        [SettingSource("Scroll Speed", "Adjust a beatmap's set scroll speed", LAST_SETTING_ORDER + 1, SettingControlType = typeof(DifficultyAdjustSettingsControl))]
+        public DifficultyBindable ScrollSpeed { get; } = new DifficultyBindable
         {
             Precision = 0.05f,
             MinValue = 0.25f,
             MaxValue = 4,
-            Default = 1,
-            Value = 1,
+            ReadCurrentFromDifficulty = _ => 1,
         };
 
         public override string SettingDescription
@@ -39,7 +37,7 @@ namespace osu.Game.Rulesets.Taiko.Mods
         {
             base.ApplySettings(difficulty);
 
-            ApplySetting(ScrollSpeed, scroll => difficulty.SliderMultiplier *= scroll);
+            if (ScrollSpeed.Value != null) difficulty.SliderMultiplier *= ScrollSpeed.Value.Value;
         }
     }
 }

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableSwell.cs

@@ -227,7 +227,7 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables
         {
             base.UpdateStartTimeStateTransforms();
 
-            using (BeginDelayedSequence(-ring_appear_offset, true))
+            using (BeginDelayedSequence(-ring_appear_offset))
                 targetRing.ScaleTo(target_ring_scale, 400, Easing.OutQuint);
         }
 

osu.Game.Tests/Beatmaps/SliderEventGenerationTest.cs

@@ -16,7 +16,7 @@ namespace osu.Game.Tests.Beatmaps
         [Test]
         public void TestSingleSpan()
         {
-            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, span_duration / 2, span_duration, 1, null, default).ToArray();
+            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, span_duration / 2, span_duration, 1, null).ToArray();
 
             Assert.That(events[0].Type, Is.EqualTo(SliderEventType.Head));
             Assert.That(events[0].Time, Is.EqualTo(start_time));
@@ -31,7 +31,7 @@ namespace osu.Game.Tests.Beatmaps
         [Test]
         public void TestRepeat()
         {
-            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, span_duration / 2, span_duration, 2, null, default).ToArray();
+            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, span_duration / 2, span_duration, 2, null).ToArray();
 
             Assert.That(events[0].Type, Is.EqualTo(SliderEventType.Head));
             Assert.That(events[0].Time, Is.EqualTo(start_time));
@@ -52,7 +52,7 @@ namespace osu.Game.Tests.Beatmaps
         [Test]
         public void TestNonEvenTicks()
         {
-            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, 300, span_duration, 2, null, default).ToArray();
+            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, 300, span_duration, 2, null).ToArray();
 
             Assert.That(events[0].Type, Is.EqualTo(SliderEventType.Head));
             Assert.That(events[0].Time, Is.EqualTo(start_time));
@@ -85,7 +85,7 @@ namespace osu.Game.Tests.Beatmaps
         [Test]
         public void TestLegacyLastTickOffset()
         {
-            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, span_duration / 2, span_duration, 1, 100, default).ToArray();
+            var events = SliderEventGenerator.Generate(start_time, span_duration, 1, span_duration / 2, span_duration, 1, 100).ToArray();
 
             Assert.That(events[2].Type, Is.EqualTo(SliderEventType.LegacyLastTick));
             Assert.That(events[2].Time, Is.EqualTo(900));
@@ -97,7 +97,7 @@ namespace osu.Game.Tests.Beatmaps
             const double velocity = 5;
             const double min_distance = velocity * 10;
 
-            var events = SliderEventGenerator.Generate(start_time, span_duration, velocity, velocity, span_duration, 2, 0, default).ToArray();
+            var events = SliderEventGenerator.Generate(start_time, span_duration, velocity, velocity, span_duration, 2, 0).ToArray();
 
             Assert.Multiple(() =>
             {

osu.Game.Tests/Database/TestRealmKeyBindingStore.cs

@@ -38,19 +38,28 @@ namespace osu.Game.Tests.Database
         [Test]
         public void TestDefaultsPopulationAndQuery()
         {
-            Assert.That(query().Count, Is.EqualTo(0));
+            Assert.That(queryCount(), Is.EqualTo(0));
 
             KeyBindingContainer testContainer = new TestKeyBindingContainer();
 
             keyBindingStore.Register(testContainer);
 
-            Assert.That(query().Count, Is.EqualTo(3));
+            Assert.That(queryCount(), Is.EqualTo(3));
 
-            Assert.That(query().Where(k => k.ActionInt == (int)GlobalAction.Back).Count, Is.EqualTo(1));
-            Assert.That(query().Where(k => k.ActionInt == (int)GlobalAction.Select).Count, Is.EqualTo(2));
+            Assert.That(queryCount(GlobalAction.Back), Is.EqualTo(1));
+            Assert.That(queryCount(GlobalAction.Select), Is.EqualTo(2));
         }
 
-        private IQueryable<RealmKeyBinding> query() => realmContextFactory.Context.All<RealmKeyBinding>();
+        private int queryCount(GlobalAction? match = null)
+        {
+            using (var usage = realmContextFactory.GetForRead())
+            {
+                var results = usage.Realm.All<RealmKeyBinding>();
+                if (match.HasValue)
+                    results = results.Where(k => k.ActionInt == (int)match.Value);
+                return results.Count();
+            }
+        }
 
         [Test]
         public void TestUpdateViaQueriedReference()
@@ -59,25 +68,28 @@ namespace osu.Game.Tests.Database
 
             keyBindingStore.Register(testContainer);
 
-            var backBinding = query().Single(k => k.ActionInt == (int)GlobalAction.Back);
-
-            Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.Escape }));
-
-            var tsr = ThreadSafeReference.Create(backBinding);
-
-            using (var usage = realmContextFactory.GetForWrite())
+            using (var primaryUsage = realmContextFactory.GetForRead())
             {
-                var binding = usage.Realm.ResolveReference(tsr);
-                binding.KeyCombination = new KeyCombination(InputKey.BackSpace);
+                var backBinding = primaryUsage.Realm.All<RealmKeyBinding>().Single(k => k.ActionInt == (int)GlobalAction.Back);
 
-                usage.Commit();
+                Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.Escape }));
+
+                var tsr = ThreadSafeReference.Create(backBinding);
+
+                using (var usage = realmContextFactory.GetForWrite())
+                {
+                    var binding = usage.Realm.ResolveReference(tsr);
+                    binding.KeyCombination = new KeyCombination(InputKey.BackSpace);
+
+                    usage.Commit();
+                }
+
+                Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
+
+                // check still correct after re-query.
+                backBinding = primaryUsage.Realm.All<RealmKeyBinding>().Single(k => k.ActionInt == (int)GlobalAction.Back);
+                Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
             }
-
-            Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
-
-            // check still correct after re-query.
-            backBinding = query().Single(k => k.ActionInt == (int)GlobalAction.Back);
-            Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
         }
 
         [TearDown]

osu.Game.Tests/Editing/Checks/CheckZeroLengthObjectsTest.cs

@@ -0,0 +1,94 @@
+// 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 System.Linq;
+using Moq;
+using NUnit.Framework;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Edit.Checks;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Tests.Beatmaps;
+using osuTK;
+
+namespace osu.Game.Tests.Editing.Checks
+{
+    [TestFixture]
+    public class CheckZeroLengthObjectsTest
+    {
+        private CheckZeroLengthObjects check;
+
+        [SetUp]
+        public void Setup()
+        {
+            check = new CheckZeroLengthObjects();
+        }
+
+        [Test]
+        public void TestCircle()
+        {
+            assertOk(new List<HitObject>
+            {
+                new HitCircle { StartTime = 1000, Position = new Vector2(0, 0) }
+            });
+        }
+
+        [Test]
+        public void TestRegularSlider()
+        {
+            assertOk(new List<HitObject>
+            {
+                getSliderMock(1000).Object
+            });
+        }
+
+        [Test]
+        public void TestZeroLengthSlider()
+        {
+            assertZeroLength(new List<HitObject>
+            {
+                getSliderMock(0).Object
+            });
+        }
+
+        [Test]
+        public void TestNegativeLengthSlider()
+        {
+            assertZeroLength(new List<HitObject>
+            {
+                getSliderMock(-1000).Object
+            });
+        }
+
+        private Mock<Slider> getSliderMock(double duration)
+        {
+            var mockSlider = new Mock<Slider>();
+            mockSlider.As<IHasDuration>().Setup(d => d.Duration).Returns(duration);
+
+            return mockSlider;
+        }
+
+        private void assertOk(List<HitObject> hitObjects)
+        {
+            Assert.That(check.Run(getContext(hitObjects)), Is.Empty);
+        }
+
+        private void assertZeroLength(List<HitObject> hitObjects)
+        {
+            var issues = check.Run(getContext(hitObjects)).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.First().Template is CheckZeroLengthObjects.IssueTemplateZeroLength);
+        }
+
+        private BeatmapVerifierContext getContext(List<HitObject> hitObjects)
+        {
+            var beatmap = new Beatmap<HitObject> { HitObjects = hitObjects };
+
+            return new BeatmapVerifierContext(beatmap, new TestWorkingBeatmap(beatmap));
+        }
+    }
+}

osu.Game.Tests/Localisation/BeatmapMetadataRomanisationTest.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 NUnit.Framework;
+using osu.Game.Beatmaps;
+
+namespace osu.Game.Tests.Localisation
+{
+    [TestFixture]
+    public class BeatmapMetadataRomanisationTest
+    {
+        [Test]
+        public void TestRomanisation()
+        {
+            var metadata = new BeatmapMetadata
+            {
+                Artist = "Romanised Artist",
+                ArtistUnicode = "Unicode Artist",
+                Title = "Romanised title",
+                TitleUnicode = "Unicode Title"
+            };
+            var romanisableString = metadata.ToRomanisableString();
+
+            Assert.AreEqual(metadata.ToString(), romanisableString.Romanised);
+            Assert.AreEqual($"{metadata.ArtistUnicode} - {metadata.TitleUnicode}", romanisableString.Original);
+        }
+
+        [Test]
+        public void TestRomanisationNoUnicode()
+        {
+            var metadata = new BeatmapMetadata
+            {
+                Artist = "Romanised Artist",
+                Title = "Romanised title"
+            };
+            var romanisableString = metadata.ToRomanisableString();
+
+            Assert.AreEqual(romanisableString.Romanised, romanisableString.Original);
+        }
+    }
+}

osu.Game.Tests/Mods/ModDifficultyAdjustTest.cs

@@ -0,0 +1,165 @@
+// 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.Beatmaps;
+using osu.Game.Online.API;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Difficulty;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.UI;
+
+namespace osu.Game.Tests.Mods
+{
+    [TestFixture]
+    public class ModDifficultyAdjustTest
+    {
+        private TestModDifficultyAdjust testMod;
+
+        [SetUp]
+        public void Setup()
+        {
+            testMod = new TestModDifficultyAdjust();
+        }
+
+        [Test]
+        public void TestUnchangedSettingsFollowAppliedDifficulty()
+        {
+            var result = applyDifficulty(new BeatmapDifficulty
+            {
+                DrainRate = 10,
+                OverallDifficulty = 10
+            });
+
+            Assert.That(result.DrainRate, Is.EqualTo(10));
+            Assert.That(result.OverallDifficulty, Is.EqualTo(10));
+
+            result = applyDifficulty(new BeatmapDifficulty
+            {
+                DrainRate = 1,
+                OverallDifficulty = 1
+            });
+
+            Assert.That(result.DrainRate, Is.EqualTo(1));
+            Assert.That(result.OverallDifficulty, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestChangedSettingsOverrideAppliedDifficulty()
+        {
+            testMod.OverallDifficulty.Value = 4;
+
+            var result = applyDifficulty(new BeatmapDifficulty
+            {
+                DrainRate = 10,
+                OverallDifficulty = 10
+            });
+
+            Assert.That(result.DrainRate, Is.EqualTo(10));
+            Assert.That(result.OverallDifficulty, Is.EqualTo(4));
+
+            result = applyDifficulty(new BeatmapDifficulty
+            {
+                DrainRate = 1,
+                OverallDifficulty = 1
+            });
+
+            Assert.That(result.DrainRate, Is.EqualTo(1));
+            Assert.That(result.OverallDifficulty, Is.EqualTo(4));
+        }
+
+        [Test]
+        public void TestChangedSettingsRetainedWhenSameValueIsApplied()
+        {
+            testMod.OverallDifficulty.Value = 4;
+
+            // Apply and de-apply the same value as the mod.
+            applyDifficulty(new BeatmapDifficulty { OverallDifficulty = 4 });
+            var result = applyDifficulty(new BeatmapDifficulty { OverallDifficulty = 10 });
+
+            Assert.That(result.OverallDifficulty, Is.EqualTo(4));
+        }
+
+        [Test]
+        public void TestChangedSettingSerialisedWhenSameValueIsApplied()
+        {
+            applyDifficulty(new BeatmapDifficulty { OverallDifficulty = 4 });
+            testMod.OverallDifficulty.Value = 4;
+
+            var result = (TestModDifficultyAdjust)new APIMod(testMod).ToMod(new TestRuleset());
+
+            Assert.That(result.OverallDifficulty.Value, Is.EqualTo(4));
+        }
+
+        [Test]
+        public void TestChangedSettingsRevertedToDefault()
+        {
+            applyDifficulty(new BeatmapDifficulty
+            {
+                DrainRate = 10,
+                OverallDifficulty = 10
+            });
+
+            testMod.OverallDifficulty.Value = 4;
+            testMod.ResetSettingsToDefaults();
+
+            Assert.That(testMod.DrainRate.Value, Is.Null);
+            Assert.That(testMod.OverallDifficulty.Value, Is.Null);
+
+            var applied = applyDifficulty(new BeatmapDifficulty
+            {
+                DrainRate = 10,
+                OverallDifficulty = 10
+            });
+
+            Assert.That(applied.OverallDifficulty, Is.EqualTo(10));
+        }
+
+        /// <summary>
+        /// Applies a <see cref="BeatmapDifficulty"/> to the mod and returns a new <see cref="BeatmapDifficulty"/>
+        /// representing the result if the mod were applied to a fresh <see cref="BeatmapDifficulty"/> instance.
+        /// </summary>
+        private BeatmapDifficulty applyDifficulty(BeatmapDifficulty difficulty)
+        {
+            // ensure that ReadFromDifficulty doesn't pollute the values.
+            var newDifficulty = difficulty.Clone();
+
+            testMod.ReadFromDifficulty(difficulty);
+
+            testMod.ApplyToDifficulty(newDifficulty);
+            return newDifficulty;
+        }
+
+        private class TestModDifficultyAdjust : ModDifficultyAdjust
+        {
+        }
+
+        private class TestRuleset : Ruleset
+        {
+            public override IEnumerable<Mod> GetModsFor(ModType type)
+            {
+                if (type == ModType.DifficultyIncrease)
+                    yield return new TestModDifficultyAdjust();
+            }
+
+            public override DrawableRuleset CreateDrawableRulesetWith(IBeatmap beatmap, IReadOnlyList<Mod> mods = null)
+            {
+                throw new System.NotImplementedException();
+            }
+
+            public override IBeatmapConverter CreateBeatmapConverter(IBeatmap beatmap)
+            {
+                throw new System.NotImplementedException();
+            }
+
+            public override DifficultyCalculator CreateDifficultyCalculator(WorkingBeatmap beatmap)
+            {
+                throw new System.NotImplementedException();
+            }
+
+            public override string Description => string.Empty;
+            public override string ShortName => string.Empty;
+        }
+    }
+}

osu.Game.Tests/NonVisual/CustomDataDirectoryTest.cs

@@ -184,6 +184,9 @@ namespace osu.Game.Tests.NonVisual
                     Assert.DoesNotThrow(() => osu.Migrate(customPath2));
                     Assert.That(File.Exists(Path.Combine(customPath2, database_filename)));
 
+                    // some files may have been left behind for whatever reason, but that's not what we're testing here.
+                    customPath = prepareCustomPath();
+
                     Assert.DoesNotThrow(() => osu.Migrate(customPath));
                     Assert.That(File.Exists(Path.Combine(customPath, database_filename)));
                 }

osu.Game.Tests/NonVisual/FirstAvailableHitWindowsTest.cs

@@ -0,0 +1,123 @@
+// 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 System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using NUnit.Framework;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Rulesets.Judgements;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu;
+using osu.Game.Rulesets.Scoring;
+using osu.Game.Rulesets.UI;
+using osu.Game.Scoring;
+
+namespace osu.Game.Tests.NonVisual
+{
+    public class FirstAvailableHitWindowsTest
+    {
+        private TestDrawableRuleset testDrawableRuleset;
+
+        [SetUp]
+        public void Setup()
+        {
+            testDrawableRuleset = new TestDrawableRuleset();
+        }
+
+        [Test]
+        public void TestResultIfOnlyParentHitWindowIsEmpty()
+        {
+            var testObject = new TestHitObject(HitWindows.Empty);
+            HitObject nested = new TestHitObject(new HitWindows());
+            testObject.AddNested(nested);
+            testDrawableRuleset.HitObjects = new List<HitObject> { testObject };
+
+            Assert.AreSame(testDrawableRuleset.FirstAvailableHitWindows, nested.HitWindows);
+        }
+
+        [Test]
+        public void TestResultIfParentHitWindowsIsNotEmpty()
+        {
+            var testObject = new TestHitObject(new HitWindows());
+            HitObject nested = new TestHitObject(new HitWindows());
+            testObject.AddNested(nested);
+            testDrawableRuleset.HitObjects = new List<HitObject> { testObject };
+
+            Assert.AreSame(testDrawableRuleset.FirstAvailableHitWindows, testObject.HitWindows);
+        }
+
+        [Test]
+        public void TestResultIfParentAndChildHitWindowsAreEmpty()
+        {
+            var firstObject = new TestHitObject(HitWindows.Empty);
+            HitObject nested = new TestHitObject(HitWindows.Empty);
+            firstObject.AddNested(nested);
+
+            var secondObject = new TestHitObject(new HitWindows());
+            testDrawableRuleset.HitObjects = new List<HitObject> { firstObject, secondObject };
+
+            Assert.AreSame(testDrawableRuleset.FirstAvailableHitWindows, secondObject.HitWindows);
+        }
+
+        [Test]
+        public void TestResultIfAllHitWindowsAreEmpty()
+        {
+            var firstObject = new TestHitObject(HitWindows.Empty);
+            HitObject nested = new TestHitObject(HitWindows.Empty);
+            firstObject.AddNested(nested);
+
+            testDrawableRuleset.HitObjects = new List<HitObject> { firstObject };
+
+            Assert.IsNull(testDrawableRuleset.FirstAvailableHitWindows);
+        }
+
+        [SuppressMessage("ReSharper", "UnassignedGetOnlyAutoProperty")]
+        private class TestDrawableRuleset : DrawableRuleset
+        {
+            public List<HitObject> HitObjects;
+            public override IEnumerable<HitObject> Objects => HitObjects;
+
+            public override event Action<JudgementResult> NewResult;
+            public override event Action<JudgementResult> RevertResult;
+
+            public override Playfield Playfield { get; }
+            public override Container Overlays { get; }
+            public override Container FrameStableComponents { get; }
+            public override IFrameStableClock FrameStableClock { get; }
+            internal override bool FrameStablePlayback { get; set; }
+            public override IReadOnlyList<Mod> Mods { get; }
+
+            public override double GameplayStartTime { get; }
+            public override GameplayCursorContainer Cursor { get; }
+
+            public TestDrawableRuleset()
+                : base(new OsuRuleset())
+            {
+                // won't compile without this.
+                NewResult?.Invoke(null);
+                RevertResult?.Invoke(null);
+            }
+
+            public override void SetReplayScore(Score replayScore) => throw new NotImplementedException();
+
+            public override void SetRecordTarget(Score score) => throw new NotImplementedException();
+
+            public override void RequestResume(Action continueResume) => throw new NotImplementedException();
+
+            public override void CancelResume() => throw new NotImplementedException();
+        }
+
+        public class TestHitObject : HitObject
+        {
+            public TestHitObject(HitWindows hitWindows)
+            {
+                HitWindows = hitWindows;
+                HitWindows.SetDifficulty(0.5f);
+            }
+
+            public new void AddNested(HitObject nested) => base.AddNested(nested);
+        }
+    }
+}

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

@@ -7,6 +7,7 @@ using NUnit.Framework;
 using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Testing;
 using osu.Game.Online.Multiplayer;
+using osu.Game.Online.Rooms;
 using osu.Game.Tests.Visual.Multiplayer;
 using osu.Game.Users;
 
@@ -50,7 +51,10 @@ namespace osu.Game.Tests.NonVisual.Multiplayer
 
             AddStep("create room initially in gameplay", () =>
             {
-                Room.RoomID.Value = null;
+                var newRoom = new Room();
+                newRoom.CopyFrom(SelectedRoom.Value);
+
+                newRoom.RoomID.Value = null;
                 Client.RoomSetupAction = room =>
                 {
                     room.State = MultiplayerRoomState.Playing;
@@ -61,7 +65,7 @@ namespace osu.Game.Tests.NonVisual.Multiplayer
                     });
                 };
 
-                RoomManager.CreateRoom(Room);
+                RoomManager.CreateRoom(newRoom);
             });
 
             AddUntilStep("wait for room join", () => Client.Room != null);

osu.Game.Tests/OnlinePlay/TestSceneCatchUpSyncManager.cs

@@ -31,32 +31,24 @@ namespace osu.Game.Tests.OnlinePlay
         }
 
         [Test]
-        public void TestMasterClockStartsWhenAllPlayerClocksHaveFrames()
+        public void TestPlayerClocksStartWhenAllHaveFrames()
         {
             setWaiting(() => player1, false);
-            assertMasterState(false);
             assertPlayerClockState(() => player1, false);
             assertPlayerClockState(() => player2, false);
 
             setWaiting(() => player2, false);
-            assertMasterState(true);
             assertPlayerClockState(() => player1, true);
             assertPlayerClockState(() => player2, true);
         }
 
         [Test]
-        public void TestMasterClockDoesNotStartWhenNoneReadyForMaximumDelayTime()
-        {
-            AddWaitStep($"wait {CatchUpSyncManager.MAXIMUM_START_DELAY} milliseconds", (int)Math.Ceiling(CatchUpSyncManager.MAXIMUM_START_DELAY / TimePerAction));
-            assertMasterState(false);
-        }
-
-        [Test]
-        public void TestMasterClockStartsWhenAnyReadyForMaximumDelayTime()
+        public void TestReadyPlayersStartWhenReadyForMaximumDelayTime()
         {
             setWaiting(() => player1, false);
             AddWaitStep($"wait {CatchUpSyncManager.MAXIMUM_START_DELAY} milliseconds", (int)Math.Ceiling(CatchUpSyncManager.MAXIMUM_START_DELAY / TimePerAction));
-            assertMasterState(true);
+            assertPlayerClockState(() => player1, true);
+            assertPlayerClockState(() => player2, false);
         }
 
         [Test]
@@ -153,9 +145,6 @@ namespace osu.Game.Tests.OnlinePlay
         private void setPlayerClockTime(Func<TestSpectatorPlayerClock> playerClock, double offsetFromMaster)
             => AddStep($"set player clock {playerClock().Id} = master - {offsetFromMaster}", () => playerClock().Seek(master.CurrentTime - offsetFromMaster));
 
-        private void assertMasterState(bool running)
-            => AddAssert($"master clock {(running ? "is" : "is not")} running", () => master.IsRunning == running);
-
         private void assertCatchingUp(Func<TestSpectatorPlayerClock> playerClock, bool catchingUp) =>
             AddAssert($"player clock {playerClock().Id} {(catchingUp ? "is" : "is not")} catching up", () => playerClock().IsCatchingUp == catchingUp);
 
@@ -201,6 +190,11 @@ namespace osu.Game.Tests.OnlinePlay
 
         private class TestManualClock : ManualClock, IAdjustableClock
         {
+            public TestManualClock()
+            {
+                IsRunning = true;
+            }
+
             public void Start() => IsRunning = true;
 
             public void Stop() => IsRunning = false;

osu.Game.Tests/Resources/Shaders/sh_TestFragment.fs

@@ -0,0 +1,11 @@
+#include "sh_Utils.h"
+
+varying mediump vec2 v_TexCoord;
+varying mediump vec4 v_TexRect;
+
+void main(void)
+{
+    float hueValue = v_TexCoord.x / (v_TexRect[2] - v_TexRect[0]);
+    gl_FragColor = hsv2rgb(vec4(hueValue, 1, 1, 1));
+}
+

osu.Game.Tests/Resources/Shaders/sh_TestVertex.vs

@@ -0,0 +1,31 @@
+#include "sh_Utils.h"
+
+attribute highp vec2 m_Position;
+attribute lowp vec4 m_Colour;
+attribute mediump vec2 m_TexCoord;
+attribute mediump vec4 m_TexRect;
+attribute mediump vec2 m_BlendRange;
+
+varying highp vec2 v_MaskingPosition;
+varying lowp vec4 v_Colour;
+varying mediump vec2 v_TexCoord;
+varying mediump vec4 v_TexRect;
+varying mediump vec2 v_BlendRange;
+
+uniform highp mat4 g_ProjMatrix;
+uniform highp mat3 g_ToMaskingSpace;
+
+void main(void)
+{
+    // Transform from screen space to masking space.
+    highp vec3 maskingPos = g_ToMaskingSpace * vec3(m_Position, 1.0);
+    v_MaskingPosition = maskingPos.xy / maskingPos.z;
+
+    v_Colour = m_Colour;
+    v_TexCoord = m_TexCoord;
+    v_TexRect = m_TexRect;
+    v_BlendRange = m_BlendRange;
+
+    gl_Position = gProjMatrix * vec4(m_Position, 1.0, 1.0);
+}
+

osu.Game.Tests/Rulesets/TestSceneDrawableRulesetDependencies.cs

@@ -13,8 +13,10 @@ using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.OpenGL.Textures;
+using osu.Framework.Graphics.Shaders;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Textures;
+using osu.Framework.IO.Stores;
 using osu.Framework.Testing;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Rulesets.UI;
@@ -31,12 +33,14 @@ namespace osu.Game.Tests.Rulesets
             DrawableWithDependencies drawable = null;
             TestTextureStore textureStore = null;
             TestSampleStore sampleStore = null;
+            TestShaderManager shaderManager = null;
 
             AddStep("add dependencies", () =>
             {
                 Child = drawable = new DrawableWithDependencies();
                 textureStore = drawable.ParentTextureStore;
                 sampleStore = drawable.ParentSampleStore;
+                shaderManager = drawable.ParentShaderManager;
             });
 
             AddStep("clear children", Clear);
@@ -52,12 +56,14 @@ namespace osu.Game.Tests.Rulesets
 
             AddAssert("parent texture store not disposed", () => !textureStore.IsDisposed);
             AddAssert("parent sample store not disposed", () => !sampleStore.IsDisposed);
+            AddAssert("parent shader manager not disposed", () => !shaderManager.IsDisposed);
         }
 
         private class DrawableWithDependencies : CompositeDrawable
         {
             public TestTextureStore ParentTextureStore { get; private set; }
             public TestSampleStore ParentSampleStore { get; private set; }
+            public TestShaderManager ParentShaderManager { get; private set; }
 
             public DrawableWithDependencies()
             {
@@ -70,6 +76,7 @@ namespace osu.Game.Tests.Rulesets
 
                 dependencies.CacheAs<TextureStore>(ParentTextureStore = new TestTextureStore());
                 dependencies.CacheAs<ISampleStore>(ParentSampleStore = new TestSampleStore());
+                dependencies.CacheAs<ShaderManager>(ParentShaderManager = new TestShaderManager());
 
                 return new DrawableRulesetDependencies(new OsuRuleset(), dependencies);
             }
@@ -135,5 +142,23 @@ namespace osu.Game.Tests.Rulesets
 
             public int PlaybackConcurrency { get; set; }
         }
+
+        private class TestShaderManager : ShaderManager
+        {
+            public TestShaderManager()
+                : base(new ResourceStore<byte[]>())
+            {
+            }
+
+            public override byte[] LoadRaw(string name) => null;
+
+            public bool IsDisposed { get; private set; }
+
+            protected override void Dispose(bool disposing)
+            {
+                base.Dispose(disposing);
+                IsDisposed = true;
+            }
+        }
     }
 }

osu.Game.Tests/Rulesets/TestSceneRulesetSkinProvidingContainer.cs

@@ -2,14 +2,15 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Audio.Sample;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.OpenGL.Textures;
 using osu.Framework.Graphics.Textures;
+using osu.Framework.Testing;
 using osu.Game.Audio;
 using osu.Game.Rulesets;
 using osu.Game.Skinning;
@@ -18,14 +19,21 @@ using osu.Game.Tests.Visual;
 
 namespace osu.Game.Tests.Rulesets
 {
+    [HeadlessTest]
     public class TestSceneRulesetSkinProvidingContainer : OsuTestScene
     {
         private SkinRequester requester;
 
         protected override Ruleset CreateRuleset() => new TestSceneRulesetDependencies.TestRuleset();
 
-        [Cached(typeof(ISkinSource))]
-        private readonly ISkinSource testSource = new TestSkinProvider();
+        [Test]
+        public void TestRulesetResources()
+        {
+            setupProviderStep();
+
+            AddAssert("ruleset texture retrieved via skin", () => requester.GetTexture("test-image") != null);
+            AddAssert("ruleset sample retrieved via skin", () => requester.GetSample(new SampleInfo("test-sample")) != null);
+        }
 
         [Test]
         public void TestEarlyAddedSkinRequester()
@@ -38,7 +46,7 @@ namespace osu.Game.Tests.Rulesets
 
                 rulesetSkinProvider.Add(requester = new SkinRequester());
 
-                requester.OnLoadAsync += () => textureOnLoad = requester.GetTexture(TestSkinProvider.TEXTURE_NAME);
+                requester.OnLoadAsync += () => textureOnLoad = requester.GetTexture("test-image");
 
                 Child = rulesetSkinProvider;
             });
@@ -46,6 +54,15 @@ namespace osu.Game.Tests.Rulesets
             AddAssert("requester got correct initial texture", () => textureOnLoad != null);
         }
 
+        private void setupProviderStep()
+        {
+            AddStep("setup provider", () =>
+            {
+                Child = new RulesetSkinProvidingContainer(Ruleset.Value.CreateInstance(), Beatmap.Value.Beatmap, Beatmap.Value.Skin)
+                    .WithChild(requester = new SkinRequester());
+            });
+        }
+
         private class SkinRequester : Drawable, ISkin
         {
             private ISkinSource skin;
@@ -68,28 +85,5 @@ namespace osu.Game.Tests.Rulesets
 
             public IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup) => skin.GetConfig<TLookup, TValue>(lookup);
         }
-
-        private class TestSkinProvider : ISkinSource
-        {
-            public const string TEXTURE_NAME = "some-texture";
-
-            public Drawable GetDrawableComponent(ISkinComponent component) => throw new NotImplementedException();
-
-            public Texture GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT) => componentName == TEXTURE_NAME ? Texture.WhitePixel : null;
-
-            public ISample GetSample(ISampleInfo sampleInfo) => throw new NotImplementedException();
-
-            public IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup) => throw new NotImplementedException();
-
-            public event Action SourceChanged
-            {
-                add { }
-                remove { }
-            }
-
-            public ISkin FindProvider(Func<ISkin, bool> lookupFunction) => lookupFunction(this) ? this : null;
-
-            public IEnumerable<ISkin> AllSources => new[] { this };
-        }
     }
 }

osu.Game.Tests/Skins/TestSceneSkinProvidingContainer.cs

@@ -0,0 +1,94 @@
+// 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 System.Linq;
+using NUnit.Framework;
+using osu.Framework.Audio.Sample;
+using osu.Framework.Bindables;
+using osu.Framework.Extensions.IEnumerableExtensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.OpenGL.Textures;
+using osu.Framework.Graphics.Textures;
+using osu.Framework.Testing;
+using osu.Game.Audio;
+using osu.Game.Skinning;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Tests.Skins
+{
+    [HeadlessTest]
+    public class TestSceneSkinProvidingContainer : OsuTestScene
+    {
+        /// <summary>
+        /// Ensures that the first inserted skin after resetting (via source change)
+        /// is always prioritised over others when providing the same resource.
+        /// </summary>
+        [Test]
+        public void TestPriorityPreservation()
+        {
+            TestSkinProvidingContainer provider = null;
+            TestSkin mostPrioritisedSource = null;
+
+            AddStep("setup sources", () =>
+            {
+                var sources = new List<TestSkin>();
+                for (int i = 0; i < 10; i++)
+                    sources.Add(new TestSkin());
+
+                mostPrioritisedSource = sources.First();
+
+                Child = provider = new TestSkinProvidingContainer(sources);
+            });
+
+            AddAssert("texture provided by expected skin", () =>
+            {
+                return provider.FindProvider(s => s.GetTexture(TestSkin.TEXTURE_NAME) != null) == mostPrioritisedSource;
+            });
+
+            AddStep("trigger source change", () => provider.TriggerSourceChanged());
+
+            AddAssert("texture still provided by expected skin", () =>
+            {
+                return provider.FindProvider(s => s.GetTexture(TestSkin.TEXTURE_NAME) != null) == mostPrioritisedSource;
+            });
+        }
+
+        private class TestSkinProvidingContainer : SkinProvidingContainer
+        {
+            private readonly IEnumerable<ISkin> sources;
+
+            public TestSkinProvidingContainer(IEnumerable<ISkin> sources)
+            {
+                this.sources = sources;
+            }
+
+            public new void TriggerSourceChanged() => base.TriggerSourceChanged();
+
+            protected override void OnSourceChanged()
+            {
+                ResetSources();
+                sources.ForEach(AddSource);
+            }
+        }
+
+        private class TestSkin : ISkin
+        {
+            public const string TEXTURE_NAME = "virtual-texture";
+
+            public Drawable GetDrawableComponent(ISkinComponent component) => throw new System.NotImplementedException();
+
+            public Texture GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT)
+            {
+                if (componentName == TEXTURE_NAME)
+                    return Texture.WhitePixel;
+
+                return null;
+            }
+
+            public ISample GetSample(ISampleInfo sampleInfo) => throw new System.NotImplementedException();
+
+            public IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup) => throw new System.NotImplementedException();
+        }
+    }
+}

osu.Game.Tests/Testing/TestSceneRulesetDependencies.cs

@@ -7,6 +7,7 @@ using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Audio.Sample;
 using osu.Framework.Configuration.Tracking;
+using osu.Framework.Graphics.Shaders;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.IO.Stores;
 using osu.Framework.Testing;
@@ -45,6 +46,14 @@ namespace osu.Game.Tests.Testing
                 Dependencies.Get<ISampleStore>().Get(@"test-sample") != null);
         }
 
+        [Test]
+        public void TestRetrieveShader()
+        {
+            AddAssert("ruleset shaders retrieved", () =>
+                Dependencies.Get<ShaderManager>().LoadRaw(@"sh_TestVertex.vs") != null &&
+                Dependencies.Get<ShaderManager>().LoadRaw(@"sh_TestFragment.fs") != null);
+        }
+
         [Test]
         public void TestResolveConfigManager()
         {

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

@@ -11,7 +11,6 @@ using osu.Game.Rulesets.Scoring;
 using osu.Game.Screens.Play;
 using osu.Game.Screens.Play.Break;
 using osu.Game.Screens.Ranking;
-using osuTK.Input;
 
 namespace osu.Game.Tests.Visual.Gameplay
 {
@@ -36,18 +35,6 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("rewind", () => Player.GameplayClockContainer.Seek(-80000));
             AddUntilStep("key counter reset", () => Player.HUDOverlay.KeyCounter.Children.All(kc => kc.CountPresses == 0));
 
-            double? time = null;
-
-            AddStep("store time", () => time = Player.GameplayClockContainer.GameplayClock.CurrentTime);
-
-            // test seek via keyboard
-            AddStep("seek with right arrow key", () => InputManager.Key(Key.Right));
-            AddAssert("time seeked forward", () => Player.GameplayClockContainer.GameplayClock.CurrentTime > time + 2000);
-
-            AddStep("store time", () => time = Player.GameplayClockContainer.GameplayClock.CurrentTime);
-            AddStep("seek with left arrow key", () => InputManager.Key(Key.Left));
-            AddAssert("time seeked backward", () => Player.GameplayClockContainer.GameplayClock.CurrentTime < time);
-
             seekToBreak(0);
             seekToBreak(1);
 

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

@@ -114,11 +114,6 @@ namespace osu.Game.Tests.Visual.Gameplay
         {
             public bool ResultsCreated { get; private set; }
 
-            public FakeRankingPushPlayer()
-                : base(true, true)
-            {
-            }
-
             protected override ResultsScreen CreateResults(ScoreInfo score)
             {
                 var results = base.CreateResults(score);

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

@@ -87,7 +87,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             showOverlay();
 
             AddStep("Up arrow", () => InputManager.Key(Key.Up));
-            AddAssert("Last button selected", () => pauseOverlay.Buttons.Last().Selected.Value);
+            AddAssert("Last button selected", () => pauseOverlay.Buttons.Last().State == SelectionState.Selected);
         }
 
         /// <summary>
@@ -99,7 +99,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             showOverlay();
 
             AddStep("Down arrow", () => InputManager.Key(Key.Down));
-            AddAssert("First button selected", () => getButton(0).Selected.Value);
+            AddAssert("First button selected", () => getButton(0).State == SelectionState.Selected);
         }
 
         /// <summary>
@@ -111,11 +111,11 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("Show overlay", () => failOverlay.Show());
 
             AddStep("Up arrow", () => InputManager.Key(Key.Up));
-            AddAssert("Last button selected", () => failOverlay.Buttons.Last().Selected.Value);
+            AddAssert("Last button selected", () => failOverlay.Buttons.Last().State == SelectionState.Selected);
             AddStep("Up arrow", () => InputManager.Key(Key.Up));
-            AddAssert("First button selected", () => failOverlay.Buttons.First().Selected.Value);
+            AddAssert("First button selected", () => failOverlay.Buttons.First().State == SelectionState.Selected);
             AddStep("Up arrow", () => InputManager.Key(Key.Up));
-            AddAssert("Last button selected", () => failOverlay.Buttons.Last().Selected.Value);
+            AddAssert("Last button selected", () => failOverlay.Buttons.Last().State == SelectionState.Selected);
         }
 
         /// <summary>
@@ -127,11 +127,11 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("Show overlay", () => failOverlay.Show());
 
             AddStep("Down arrow", () => InputManager.Key(Key.Down));
-            AddAssert("First button selected", () => failOverlay.Buttons.First().Selected.Value);
+            AddAssert("First button selected", () => failOverlay.Buttons.First().State == SelectionState.Selected);
             AddStep("Down arrow", () => InputManager.Key(Key.Down));
-            AddAssert("Last button selected", () => failOverlay.Buttons.Last().Selected.Value);
+            AddAssert("Last button selected", () => failOverlay.Buttons.Last().State == SelectionState.Selected);
             AddStep("Down arrow", () => InputManager.Key(Key.Down));
-            AddAssert("First button selected", () => failOverlay.Buttons.First().Selected.Value);
+            AddAssert("First button selected", () => failOverlay.Buttons.First().State == SelectionState.Selected);
         }
 
         /// <summary>
@@ -145,7 +145,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("Hover first button", () => InputManager.MoveMouseTo(failOverlay.Buttons.First()));
             AddStep("Hide overlay", () => failOverlay.Hide());
 
-            AddAssert("Overlay state is reset", () => !failOverlay.Buttons.Any(b => b.Selected.Value));
+            AddAssert("Overlay state is reset", () => failOverlay.Buttons.All(b => b.State == SelectionState.NotSelected));
         }
 
         /// <summary>
@@ -162,11 +162,11 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("Hide overlay", () => pauseOverlay.Hide());
             showOverlay();
 
-            AddAssert("First button not selected", () => !getButton(0).Selected.Value);
+            AddAssert("First button not selected", () => getButton(0).State == SelectionState.NotSelected);
 
             AddStep("Move slightly", () => InputManager.MoveMouseTo(InputManager.CurrentState.Mouse.Position + new Vector2(1)));
 
-            AddAssert("First button selected", () => getButton(0).Selected.Value);
+            AddAssert("First button selected", () => getButton(0).State == SelectionState.Selected);
         }
 
         /// <summary>
@@ -179,8 +179,8 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             AddStep("Down arrow", () => InputManager.Key(Key.Down));
             AddStep("Hover second button", () => InputManager.MoveMouseTo(getButton(1)));
-            AddAssert("First button not selected", () => !getButton(0).Selected.Value);
-            AddAssert("Second button selected", () => getButton(1).Selected.Value);
+            AddAssert("First button not selected", () => getButton(0).State == SelectionState.NotSelected);
+            AddAssert("Second button selected", () => getButton(1).State == SelectionState.Selected);
         }
 
         /// <summary>
@@ -196,8 +196,8 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             AddStep("Hover second button", () => InputManager.MoveMouseTo(getButton(1)));
             AddStep("Up arrow", () => InputManager.Key(Key.Up));
-            AddAssert("Second button not selected", () => !getButton(1).Selected.Value);
-            AddAssert("First button selected", () => getButton(0).Selected.Value);
+            AddAssert("Second button not selected", () => getButton(1).State == SelectionState.NotSelected);
+            AddAssert("First button selected", () => getButton(0).State == SelectionState.Selected);
         }
 
         /// <summary>
@@ -211,7 +211,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("Hover second button", () => InputManager.MoveMouseTo(getButton(1)));
             AddStep("Unhover second button", () => InputManager.MoveMouseTo(Vector2.Zero));
             AddStep("Down arrow", () => InputManager.Key(Key.Down));
-            AddAssert("First button selected", () => getButton(0).Selected.Value); // Initial state condition
+            AddAssert("First button selected", () => getButton(0).State == SelectionState.Selected); // Initial state condition
         }
 
         /// <summary>
@@ -282,7 +282,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             showOverlay();
 
             AddAssert("No button selected",
-                () => pauseOverlay.Buttons.All(button => !button.Selected.Value));
+                () => pauseOverlay.Buttons.All(button => button.State == SelectionState.NotSelected));
         }
 
         private void showOverlay() => AddStep("Show overlay", () => pauseOverlay.Show());

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

@@ -0,0 +1,246 @@
+// 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 System.Linq;
+using NUnit.Framework;
+using osu.Framework.Screens;
+using osu.Game.Beatmaps;
+using osu.Game.Online.API;
+using osu.Game.Online.Rooms;
+using osu.Game.Online.Solo;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu;
+using osu.Game.Rulesets.Osu.Judgements;
+using osu.Game.Rulesets.Scoring;
+using osu.Game.Screens.Ranking;
+using osu.Game.Tests.Beatmaps;
+
+namespace osu.Game.Tests.Visual.Gameplay
+{
+    public class TestScenePlayerScoreSubmission : PlayerTestScene
+    {
+        protected override bool AllowFail => allowFail;
+
+        private bool allowFail;
+
+        private Func<RulesetInfo, IBeatmap> createCustomBeatmap;
+        private Func<Ruleset> createCustomRuleset;
+
+        private DummyAPIAccess dummyAPI => (DummyAPIAccess)API;
+
+        protected override bool HasCustomSteps => true;
+
+        protected override TestPlayer CreatePlayer(Ruleset ruleset) => new TestPlayer(false);
+
+        protected override Ruleset CreatePlayerRuleset() => createCustomRuleset?.Invoke() ?? new OsuRuleset();
+
+        protected override IBeatmap CreateBeatmap(RulesetInfo ruleset) => createCustomBeatmap?.Invoke(ruleset) ?? createTestBeatmap(ruleset);
+
+        private IBeatmap createTestBeatmap(RulesetInfo ruleset)
+        {
+            var beatmap = (TestBeatmap)base.CreateBeatmap(ruleset);
+
+            beatmap.HitObjects = beatmap.HitObjects.Take(10).ToList();
+
+            return beatmap;
+        }
+
+        [Test]
+        public void TestNoSubmissionOnResultsWithNoToken()
+        {
+            prepareTokenResponse(false);
+
+            createPlayerTest();
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            AddUntilStep("wait for track to start running", () => Beatmap.Value.Track.IsRunning);
+
+            addFakeHit();
+
+            AddStep("seek to completion", () => Player.GameplayClockContainer.Seek(Player.DrawableRuleset.Objects.Last().GetEndTime()));
+
+            AddUntilStep("results displayed", () => Player.GetChildScreen() is ResultsScreen);
+
+            AddAssert("ensure no submission", () => Player.SubmittedScore == null);
+        }
+
+        [Test]
+        public void TestSubmissionOnResults()
+        {
+            prepareTokenResponse(true);
+
+            createPlayerTest();
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            AddUntilStep("wait for track to start running", () => Beatmap.Value.Track.IsRunning);
+
+            addFakeHit();
+
+            AddStep("seek to completion", () => Player.GameplayClockContainer.Seek(Player.DrawableRuleset.Objects.Last().GetEndTime()));
+
+            AddUntilStep("results displayed", () => Player.GetChildScreen() is ResultsScreen);
+            AddAssert("ensure passing submission", () => Player.SubmittedScore?.ScoreInfo.Passed == true);
+        }
+
+        [Test]
+        public void TestNoSubmissionOnExitWithNoToken()
+        {
+            prepareTokenResponse(false);
+
+            createPlayerTest();
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            AddUntilStep("wait for track to start running", () => Beatmap.Value.Track.IsRunning);
+
+            addFakeHit();
+
+            AddStep("exit", () => Player.Exit());
+            AddAssert("ensure no submission", () => Player.SubmittedScore == null);
+        }
+
+        [Test]
+        public void TestNoSubmissionOnEmptyFail()
+        {
+            prepareTokenResponse(true);
+
+            createPlayerTest(true);
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            AddUntilStep("wait for fail", () => Player.HasFailed);
+            AddStep("exit", () => Player.Exit());
+
+            AddAssert("ensure no submission", () => Player.SubmittedScore == null);
+        }
+
+        [Test]
+        public void TestSubmissionOnFail()
+        {
+            prepareTokenResponse(true);
+
+            createPlayerTest(true);
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            addFakeHit();
+
+            AddUntilStep("wait for fail", () => Player.HasFailed);
+            AddStep("exit", () => Player.Exit());
+
+            AddAssert("ensure failing submission", () => Player.SubmittedScore?.ScoreInfo.Passed == false);
+        }
+
+        [Test]
+        public void TestNoSubmissionOnEmptyExit()
+        {
+            prepareTokenResponse(true);
+
+            createPlayerTest();
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            AddStep("exit", () => Player.Exit());
+            AddAssert("ensure no submission", () => Player.SubmittedScore == null);
+        }
+
+        [Test]
+        public void TestSubmissionOnExit()
+        {
+            prepareTokenResponse(true);
+
+            createPlayerTest();
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            addFakeHit();
+
+            AddStep("exit", () => Player.Exit());
+            AddAssert("ensure failing submission", () => Player.SubmittedScore?.ScoreInfo.Passed == false);
+        }
+
+        [Test]
+        public void TestNoSubmissionOnLocalBeatmap()
+        {
+            prepareTokenResponse(true);
+
+            createPlayerTest(false, r =>
+            {
+                var beatmap = createTestBeatmap(r);
+                beatmap.BeatmapInfo.OnlineBeatmapID = null;
+                return beatmap;
+            });
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            addFakeHit();
+
+            AddStep("exit", () => Player.Exit());
+            AddAssert("ensure no submission", () => Player.SubmittedScore == null);
+        }
+
+        [Test]
+        public void TestNoSubmissionOnCustomRuleset()
+        {
+            prepareTokenResponse(true);
+
+            createPlayerTest(false, createRuleset: () => new OsuRuleset { RulesetInfo = { ID = 10 } });
+
+            AddUntilStep("wait for token request", () => Player.TokenCreationRequested);
+
+            addFakeHit();
+
+            AddStep("exit", () => Player.Exit());
+            AddAssert("ensure no submission", () => Player.SubmittedScore == null);
+        }
+
+        private void createPlayerTest(bool allowFail = false, Func<RulesetInfo, IBeatmap> createBeatmap = null, Func<Ruleset> createRuleset = null)
+        {
+            CreateTest(() => AddStep("set up requirements", () =>
+            {
+                this.allowFail = allowFail;
+                createCustomBeatmap = createBeatmap;
+                createCustomRuleset = createRuleset;
+            }));
+        }
+
+        private void prepareTokenResponse(bool validToken)
+        {
+            AddStep("Prepare test API", () =>
+            {
+                dummyAPI.HandleRequest = request =>
+                {
+                    switch (request)
+                    {
+                        case CreateSoloScoreRequest tokenRequest:
+                            if (validToken)
+                                tokenRequest.TriggerSuccess(new APIScoreToken { ID = 1234 });
+                            else
+                                tokenRequest.TriggerFailure(new APIException("something went wrong!", null));
+                            return true;
+                    }
+
+                    return false;
+                };
+            });
+        }
+
+        private void addFakeHit()
+        {
+            AddUntilStep("wait for first result", () => Player.Results.Count > 0);
+
+            AddStep("force successfuly hit", () =>
+            {
+                Player.ScoreProcessor.RevertResult(Player.Results.First());
+                Player.ScoreProcessor.ApplyResult(new OsuJudgementResult(Beatmap.Value.Beatmap.HitObjects.First(), new OsuJudgement())
+                {
+                    Type = HitResult.Great,
+                });
+            });
+        }
+    }
+}

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

@@ -0,0 +1,87 @@
+// 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 NUnit.Framework;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Osu;
+using osuTK.Input;
+
+namespace osu.Game.Tests.Visual.Gameplay
+{
+    public class TestSceneReplayPlayer : RateAdjustedBeatmapTestScene
+    {
+        protected TestReplayPlayer Player;
+
+        public override void SetUpSteps()
+        {
+            base.SetUpSteps();
+
+            AddStep("Initialise player", () => Player = CreatePlayer(new OsuRuleset()));
+            AddStep("Load player", () => LoadScreen(Player));
+            AddUntilStep("player loaded", () => Player.IsLoaded);
+        }
+
+        [Test]
+        public void TestPause()
+        {
+            double? lastTime = null;
+
+            AddUntilStep("wait for first hit", () => Player.ScoreProcessor.TotalScore.Value > 0);
+
+            AddStep("Pause playback", () => InputManager.Key(Key.Space));
+
+            AddUntilStep("Time stopped progressing", () =>
+            {
+                double current = Player.GameplayClockContainer.CurrentTime;
+                bool changed = lastTime != current;
+                lastTime = current;
+
+                return !changed;
+            });
+
+            AddWaitStep("wait some", 10);
+
+            AddAssert("Time still stopped", () => lastTime == Player.GameplayClockContainer.CurrentTime);
+        }
+
+        [Test]
+        public void TestSeekBackwards()
+        {
+            double? lastTime = null;
+
+            AddUntilStep("wait for first hit", () => Player.ScoreProcessor.TotalScore.Value > 0);
+
+            AddStep("Seek backwards", () =>
+            {
+                lastTime = Player.GameplayClockContainer.CurrentTime;
+                InputManager.Key(Key.Left);
+            });
+
+            AddAssert("Jumped backwards", () => Player.GameplayClockContainer.CurrentTime - lastTime < 0);
+        }
+
+        [Test]
+        public void TestSeekForwards()
+        {
+            double? lastTime = null;
+
+            AddUntilStep("wait for first hit", () => Player.ScoreProcessor.TotalScore.Value > 0);
+
+            AddStep("Seek forwards", () =>
+            {
+                lastTime = Player.GameplayClockContainer.CurrentTime;
+                InputManager.Key(Key.Right);
+            });
+
+            AddAssert("Jumped forwards", () => Player.GameplayClockContainer.CurrentTime - lastTime > 500);
+        }
+
+        protected TestReplayPlayer CreatePlayer(Ruleset ruleset)
+        {
+            Beatmap.Value = CreateWorkingBeatmap(ruleset.RulesetInfo);
+            SelectedMods.Value = new[] { ruleset.GetAutoplayMod() };
+
+            return new TestReplayPlayer(false);
+        }
+    }
+}

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

@@ -75,7 +75,7 @@ namespace osu.Game.Tests.Visual.Gameplay
                         Children = new[]
                         {
                             new ExposedSkinnableDrawable("default", _ => new DefaultBox()),
-                            new ExposedSkinnableDrawable("available", _ => new DefaultBox(), ConfineMode.ScaleToFit),
+                            new ExposedSkinnableDrawable("available", _ => new DefaultBox()),
                             new ExposedSkinnableDrawable("available", _ => new DefaultBox(), ConfineMode.NoScaling)
                         }
                     },
@@ -168,7 +168,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             public void Disable()
             {
                 allow = false;
-                OnSourceChanged();
+                TriggerSourceChanged();
             }
 
             public SwitchableSkinProvidingContainer(ISkin skin)

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

@@ -2,8 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
@@ -41,8 +39,6 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Resolved]
         private OsuGameBase game { get; set; }
 
-        private int nextFrame;
-
         private BeatmapSetInfo importedBeatmap;
 
         private int importedBeatmapId;
@@ -51,8 +47,6 @@ namespace osu.Game.Tests.Visual.Gameplay
         {
             base.SetUpSteps();
 
-            AddStep("reset sent frames", () => nextFrame = 0);
-
             AddStep("import beatmap", () =>
             {
                 importedBeatmap = ImportBeatmapTest.LoadOszIntoOsu(game, virtualTrack: true).Result;
@@ -105,7 +99,8 @@ namespace osu.Game.Tests.Visual.Gameplay
             waitForPlayer();
             checkPaused(true);
 
-            sendFrames(1000); // send enough frames to ensure play won't be paused
+            // send enough frames to ensure play won't be paused
+            sendFrames(100);
 
             checkPaused(false);
         }
@@ -114,12 +109,12 @@ namespace osu.Game.Tests.Visual.Gameplay
         public void TestSpectatingDuringGameplay()
         {
             start();
+            sendFrames(300);
 
             loadSpectatingScreen();
             waitForPlayer();
 
-            AddStep("advance frame count", () => nextFrame = 300);
-            sendFrames();
+            sendFrames(300);
 
             AddUntilStep("playing from correct point in time", () => player.ChildrenOfType<DrawableRuleset>().First().FrameStableClock.CurrentTime > 30000);
         }
@@ -220,11 +215,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
         private void sendFrames(int count = 10)
         {
-            AddStep("send frames", () =>
-            {
-                testSpectatorClient.SendFrames(streamingUser.Id, nextFrame, count);
-                nextFrame += count;
-            });
+            AddStep("send frames", () => testSpectatorClient.SendFrames(streamingUser.Id, count));
         }
 
         private void loadSpectatingScreen()
@@ -232,14 +223,5 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddStep("load screen", () => LoadScreen(spectatorScreen = new SoloSpectator(streamingUser)));
             AddUntilStep("wait for screen load", () => spectatorScreen.LoadState == LoadState.Loaded);
         }
-
-        internal class TestUserLookupCache : UserLookupCache
-        {
-            protected override Task<User> ComputeValueAsync(int lookup, CancellationToken token = default) => Task.FromResult(new User
-            {
-                Id = lookup,
-                Username = $"User {lookup}"
-            });
-        }
     }
 }

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

@@ -179,7 +179,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             foreach (var legacyFrame in frames.Frames)
             {
                 var frame = new TestReplayFrame();
-                frame.FromLegacy(legacyFrame, null, null);
+                frame.FromLegacy(legacyFrame, null);
                 replay.Frames.Add(frame);
             }
         }

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

@@ -1,61 +0,0 @@
-// 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 osu.Framework.Allocation;
-using osu.Game.Beatmaps;
-using osu.Game.Online.Rooms;
-using osu.Game.Rulesets;
-using osu.Game.Screens.OnlinePlay;
-using osu.Game.Users;
-
-namespace osu.Game.Tests.Visual.Multiplayer
-{
-    public abstract class RoomManagerTestScene : RoomTestScene
-    {
-        [Cached(Type = typeof(IRoomManager))]
-        protected TestRoomManager RoomManager { get; } = new TestRoomManager();
-
-        public override void SetUpSteps()
-        {
-            base.SetUpSteps();
-
-            AddStep("clear rooms", () => RoomManager.Rooms.Clear());
-        }
-
-        protected void AddRooms(int count, RulesetInfo ruleset = null)
-        {
-            AddStep("add rooms", () =>
-            {
-                for (int i = 0; i < count; i++)
-                {
-                    var room = new Room
-                    {
-                        RoomID = { Value = i },
-                        Name = { Value = $"Room {i}" },
-                        Host = { Value = new User { Username = "Host" } },
-                        EndDate = { Value = DateTimeOffset.Now + TimeSpan.FromSeconds(10) },
-                        Category = { Value = i % 2 == 0 ? RoomCategory.Spotlight : RoomCategory.Normal }
-                    };
-
-                    if (ruleset != null)
-                    {
-                        room.Playlist.Add(new PlaylistItem
-                        {
-                            Ruleset = { Value = ruleset },
-                            Beatmap =
-                            {
-                                Value = new BeatmapInfo
-                                {
-                                    Metadata = new BeatmapMetadata()
-                                }
-                            }
-                        });
-                    }
-
-                    RoomManager.Rooms.Add(room);
-                }
-            });
-        }
-    }
-}

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

@@ -1,35 +0,0 @@
-// 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 osu.Framework.Bindables;
-using osu.Game.Online.Rooms;
-using osu.Game.Screens.OnlinePlay;
-
-namespace osu.Game.Tests.Visual.Multiplayer
-{
-    public class TestRoomManager : IRoomManager
-    {
-        public event Action RoomsUpdated
-        {
-            add { }
-            remove { }
-        }
-
-        public readonly BindableList<Room> Rooms = new BindableList<Room>();
-
-        public IBindable<bool> InitialRoomsReceived { get; } = new Bindable<bool>(true);
-
-        IBindableList<Room> IRoomManager.Rooms => Rooms;
-
-        public void CreateRoom(Room room, Action<Room> onSuccess = null, Action<string> onError = null) => Rooms.Add(room);
-
-        public void JoinRoom(Room room, Action<Room> onSuccess = null, Action<string> onError = null)
-        {
-        }
-
-        public void PartRoom()
-        {
-        }
-    }
-}

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

@@ -4,17 +4,21 @@
 using System;
 using NUnit.Framework;
 using osu.Framework.Graphics;
+using osu.Game.Online.Rooms;
 using osu.Game.Online.Rooms.RoomStatuses;
 using osu.Game.Screens.OnlinePlay.Lounge.Components;
+using osu.Game.Tests.Visual.OnlinePlay;
 using osu.Game.Users;
 
 namespace osu.Game.Tests.Visual.Multiplayer
 {
-    public class TestSceneLoungeRoomInfo : RoomTestScene
+    public class TestSceneLoungeRoomInfo : OnlinePlayTestScene
     {
         [SetUp]
         public new void Setup() => Schedule(() =>
         {
+            SelectedRoom.Value = new Room();
+
             Child = new RoomInfo
             {
                 Anchor = Anchor.Centre,
@@ -23,15 +27,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
             };
         });
 
-        public override void SetUpSteps()
-        {
-            // Todo: Temp
-        }
-
         [Test]
         public void TestNonSelectedRoom()
         {
-            AddStep("set null room", () => Room.RoomID.Value = null);
+            AddStep("set null room", () => SelectedRoom.Value.RoomID.Value = null);
         }
 
         [Test]
@@ -39,11 +38,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
         {
             AddStep("set open room", () =>
             {
-                Room.RoomID.Value = 0;
-                Room.Name.Value = "Room 0";
-                Room.Host.Value = new User { Username = "peppy", Id = 2 };
-                Room.EndDate.Value = DateTimeOffset.Now.AddMonths(1);
-                Room.Status.Value = new RoomStatusOpen();
+                SelectedRoom.Value.RoomID.Value = 0;
+                SelectedRoom.Value.Name.Value = "Room 0";
+                SelectedRoom.Value.Host.Value = new User { Username = "peppy", Id = 2 };
+                SelectedRoom.Value.EndDate.Value = DateTimeOffset.Now.AddMonths(1);
+                SelectedRoom.Value.Status.Value = new RoomStatusOpen();
             });
         }
     }

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

@@ -3,24 +3,26 @@
 
 using System.Linq;
 using NUnit.Framework;
-using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Graphics;
 using osu.Game.Online.Rooms;
 using osu.Game.Rulesets.Catch;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Screens.OnlinePlay.Lounge.Components;
+using osu.Game.Tests.Visual.OnlinePlay;
 using osuTK.Graphics;
 using osuTK.Input;
 
 namespace osu.Game.Tests.Visual.Multiplayer
 {
-    public class TestSceneLoungeRoomsContainer : RoomManagerTestScene
+    public class TestSceneLoungeRoomsContainer : OnlinePlayTestScene
     {
+        protected new BasicTestRoomManager RoomManager => (BasicTestRoomManager)base.RoomManager;
+
         private RoomsContainer container;
 
-        [BackgroundDependencyLoader]
-        private void load()
+        [SetUp]
+        public new void Setup() => Schedule(() =>
         {
             Child = container = new RoomsContainer
             {
@@ -29,12 +31,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 Width = 0.5f,
                 JoinRequested = joinRequested
             };
-        }
+        });
 
         [Test]
         public void TestBasicListChanges()
         {
-            AddRooms(3);
+            AddStep("add rooms", () => RoomManager.AddRooms(3));
 
             AddAssert("has 3 rooms", () => container.Rooms.Count == 3);
             AddStep("remove first room", () => RoomManager.Rooms.Remove(RoomManager.Rooms.FirstOrDefault()));
@@ -51,7 +53,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestKeyboardNavigation()
         {
-            AddRooms(3);
+            AddStep("add rooms", () => RoomManager.AddRooms(3));
 
             AddAssert("no selection", () => checkRoomSelected(null));
 
@@ -72,7 +74,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestClickDeselection()
         {
-            AddRooms(1);
+            AddStep("add room", () => RoomManager.AddRooms(1));
 
             AddAssert("no selection", () => checkRoomSelected(null));
 
@@ -91,7 +93,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestStringFiltering()
         {
-            AddRooms(4);
+            AddStep("add rooms", () => RoomManager.AddRooms(4));
 
             AddUntilStep("4 rooms visible", () => container.Rooms.Count(r => r.IsPresent) == 4);
 
@@ -107,21 +109,21 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [Test]
         public void TestRulesetFiltering()
         {
-            AddRooms(2, new OsuRuleset().RulesetInfo);
-            AddRooms(3, new CatchRuleset().RulesetInfo);
+            AddStep("add rooms", () => RoomManager.AddRooms(2, new OsuRuleset().RulesetInfo));
+            AddStep("add rooms", () => RoomManager.AddRooms(3, new CatchRuleset().RulesetInfo));
 
+            // Todo: What even is this case...?
+            AddStep("set empty filter criteria", () => container.Filter(null));
             AddUntilStep("5 rooms visible", () => container.Rooms.Count(r => r.IsPresent) == 5);
 
             AddStep("filter osu! rooms", () => container.Filter(new FilterCriteria { Ruleset = new OsuRuleset().RulesetInfo }));
-
             AddUntilStep("2 rooms visible", () => container.Rooms.Count(r => r.IsPresent) == 2);
 
             AddStep("filter catch rooms", () => container.Filter(new FilterCriteria { Ruleset = new CatchRuleset().RulesetInfo }));
-
             AddUntilStep("3 rooms visible", () => container.Rooms.Count(r => r.IsPresent) == 3);
         }
 
-        private bool checkRoomSelected(Room room) => Room == room;
+        private bool checkRoomSelected(Room room) => SelectedRoom.Value == room;
 
         private void joinRequested(Room room) => room.Status.Value = new JoinedRoomStatus();
 

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

@@ -11,11 +11,12 @@ using osu.Game.Rulesets.Osu;
 using osu.Game.Rulesets.Osu.Mods;
 using osu.Game.Screens.OnlinePlay.Components;
 using osu.Game.Tests.Beatmaps;
+using osu.Game.Tests.Visual.OnlinePlay;
 using osuTK;
 
 namespace osu.Game.Tests.Visual.Multiplayer
 {
-    public class TestSceneMatchBeatmapDetailArea : RoomTestScene
+    public class TestSceneMatchBeatmapDetailArea : OnlinePlayTestScene
     {
         [Resolved]
         private BeatmapManager beatmapManager { get; set; }
@@ -26,6 +27,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
         [SetUp]
         public new void Setup() => Schedule(() =>
         {
+            SelectedRoom.Value = new Room();
+
             Child = new MatchBeatmapDetailArea
             {
                 Anchor = Anchor.Centre,
@@ -37,9 +40,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         private void createNewItem()
         {
-            Room.Playlist.Add(new PlaylistItem
+            SelectedRoom.Value.Playlist.Add(new PlaylistItem
             {
-                ID = Room.Playlist.Count,
+                ID = SelectedRoom.Value.Playlist.Count,
                 Beatmap = { Value = new TestBeatmap(new OsuRuleset().RulesetInfo).BeatmapInfo },
                 Ruleset = { Value = new OsuRuleset().RulesetInfo },
                 RequiredMods =

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

@@ -7,46 +7,49 @@ using osu.Game.Online.Rooms;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Rulesets.Osu.Mods;
 using osu.Game.Screens.OnlinePlay.Match.Components;
+using osu.Game.Tests.Visual.OnlinePlay;
 using osu.Game.Users;
 
 namespace osu.Game.Tests.Visual.Multiplayer
 {
-    public class TestSceneMatchHeader : RoomTestScene
+    public class TestSceneMatchHeader : OnlinePlayTestScene
     {
-        public TestSceneMatchHeader()
-        {
-            Child = new Header();
-        }
-
         [SetUp]
         public new void Setup() => Schedule(() =>
         {
-            Room.Playlist.Add(new PlaylistItem
+            SelectedRoom.Value = new Room
             {
-                Beatmap =
+                Name = { Value = "A very awesome room" },
+                Host = { Value = new User { Id = 2, Username = "peppy" } },
+                Playlist =
                 {
-                    Value = new BeatmapInfo
+                    new PlaylistItem
                     {
-                        Metadata = new BeatmapMetadata
+                        Beatmap =
                         {
-                            Title = "Title",
-                            Artist = "Artist",
-                            AuthorString = "Author",
+                            Value = new BeatmapInfo
+                            {
+                                Metadata = new BeatmapMetadata
+                                {
+                                    Title = "Title",
+                                    Artist = "Artist",
+                                    AuthorString = "Author",
+                                },
+                                Version = "Version",
+                                Ruleset = new OsuRuleset().RulesetInfo
+                            }
                         },
-                        Version = "Version",
-                        Ruleset = new OsuRuleset().RulesetInfo
+                        RequiredMods =
+                        {
+                            new OsuModDoubleTime(),
+                            new OsuModNoFail(),
+                            new OsuModRelax(),
+                        }
                     }
-                },
-                RequiredMods =
-                {
-                    new OsuModDoubleTime(),
-                    new OsuModNoFail(),
-                    new OsuModRelax(),
                 }
-            });
+            };
 
-            Room.Name.Value = "A very awesome room";
-            Room.Host.Value = new User { Id = 2, Username = "peppy" };
+            Child = new Header();
         });
     }
 }

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

@@ -2,72 +2,74 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
-using Newtonsoft.Json;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Online.API;
+using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Online.Rooms;
 using osu.Game.Screens.OnlinePlay.Match.Components;
+using osu.Game.Tests.Visual.OnlinePlay;
 using osu.Game.Users;
 using osuTK;
 
 namespace osu.Game.Tests.Visual.Multiplayer
 {
-    public class TestSceneMatchLeaderboard : RoomTestScene
+    public class TestSceneMatchLeaderboard : OnlinePlayTestScene
     {
-        protected override bool UseOnlineAPI => true;
-
-        public TestSceneMatchLeaderboard()
-        {
-            Add(new MatchLeaderboard
-            {
-                Origin = Anchor.Centre,
-                Anchor = Anchor.Centre,
-                Size = new Vector2(550f, 450f),
-                Scope = MatchLeaderboardScope.Overall,
-            });
-        }
-
         [BackgroundDependencyLoader]
-        private void load(IAPIProvider api)
+        private void load()
         {
-            var req = new GetRoomScoresRequest();
-            req.Success += v => { };
-            req.Failure += _ => { };
+            ((DummyAPIAccess)API).HandleRequest = r =>
+            {
+                switch (r)
+                {
+                    case GetRoomLeaderboardRequest leaderboardRequest:
+                        leaderboardRequest.TriggerSuccess(new APILeaderboard
+                        {
+                            Leaderboard = new List<APIUserScoreAggregate>
+                            {
+                                new APIUserScoreAggregate
+                                {
+                                    UserID = 2,
+                                    User = new User { Id = 2, Username = "peppy" },
+                                    TotalScore = 995533,
+                                    RoomID = 3,
+                                    CompletedBeatmaps = 1,
+                                    TotalAttempts = 6,
+                                    Accuracy = 0.9851
+                                },
+                                new APIUserScoreAggregate
+                                {
+                                    UserID = 1040328,
+                                    User = new User { Id = 1040328, Username = "smoogipoo" },
+                                    TotalScore = 981100,
+                                    RoomID = 3,
+                                    CompletedBeatmaps = 1,
+                                    TotalAttempts = 9,
+                                    Accuracy = 0.937
+                                }
+                            }
+                        });
+                        return true;
+                }
 
-            api.Queue(req);
+                return false;
+            };
         }
 
         [SetUp]
         public new void Setup() => Schedule(() =>
         {
-            Room.RoomID.Value = 3;
+            SelectedRoom.Value = new Room { RoomID = { Value = 3 } };
+
+            Child = new MatchLeaderboard
+            {
+                Origin = Anchor.Centre,
+                Anchor = Anchor.Centre,
+                Size = new Vector2(550f, 450f),
+                Scope = MatchLeaderboardScope.Overall,
+            };
         });
-
-        private class GetRoomScoresRequest : APIRequest<List<RoomScore>>
-        {
-            protected override string Target => "rooms/3/leaderboard";
-        }
-
-        private class RoomScore
-        {
-            [JsonProperty("user")]
-            public User User { get; set; }
-
-            [JsonProperty("accuracy")]
-            public double Accuracy { get; set; }
-
-            [JsonProperty("total_score")]
-            public int TotalScore { get; set; }
-
-            [JsonProperty("pp")]
-            public double PP { get; set; }
-
-            [JsonProperty("attempts")]
-            public int TotalAttempts { get; set; }
-
-            [JsonProperty("completed")]
-            public int CompletedAttempts { get; set; }
-        }
     }
 }

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

@@ -3,74 +3,40 @@
 
 using System.Collections.Generic;
 using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
-using osu.Framework.Allocation;
-using osu.Framework.Graphics;
-using osu.Framework.Graphics.Containers;
 using osu.Framework.Testing;
 using osu.Framework.Timing;
-using osu.Game.Database;
-using osu.Game.Online.Spectator;
 using osu.Game.Rulesets.Osu.Scoring;
 using osu.Game.Screens.OnlinePlay.Multiplayer.Spectate;
 using osu.Game.Screens.Play.HUD;
-using osu.Game.Tests.Visual.Spectator;
-using osu.Game.Users;
 
 namespace osu.Game.Tests.Visual.Multiplayer
 {
     public class TestSceneMultiSpectatorLeaderboard : MultiplayerTestScene
     {
-        [Cached(typeof(SpectatorClient))]
-        private TestSpectatorClient spectatorClient = new TestSpectatorClient();
-
-        [Cached(typeof(UserLookupCache))]
-        private UserLookupCache lookupCache = new TestUserLookupCache();
-
-        protected override Container<Drawable> Content => content;
-        private readonly Container content;
-
-        private readonly Dictionary<int, ManualClock> clocks = new Dictionary<int, ManualClock>
-        {
-            { PLAYER_1_ID, new ManualClock() },
-            { PLAYER_2_ID, new ManualClock() }
-        };
-
-        public TestSceneMultiSpectatorLeaderboard()
-        {
-            base.Content.AddRange(new Drawable[]
-            {
-                spectatorClient,
-                lookupCache,
-                content = new Container { RelativeSizeAxes = Axes.Both }
-            });
-        }
+        private Dictionary<int, ManualClock> clocks;
+        private MultiSpectatorLeaderboard leaderboard;
 
         [SetUpSteps]
         public new void SetUpSteps()
         {
-            MultiSpectatorLeaderboard leaderboard = null;
-
             AddStep("reset", () =>
             {
                 Clear();
 
-                foreach (var (userId, clock) in clocks)
+                clocks = new Dictionary<int, ManualClock>
                 {
-                    spectatorClient.EndPlay(userId);
-                    clock.CurrentTime = 0;
-                }
+                    { PLAYER_1_ID, new ManualClock() },
+                    { PLAYER_2_ID, new ManualClock() }
+                };
+
+                foreach (var (userId, _) in clocks)
+                    SpectatorClient.StartPlay(userId, 0);
             });
 
             AddStep("create leaderboard", () =>
             {
-                foreach (var (userId, _) in clocks)
-                    spectatorClient.StartPlay(userId, 0);
-
                 Beatmap.Value = CreateWorkingBeatmap(Ruleset.Value);
-
                 var playable = Beatmap.Value.GetPlayableBeatmap(Ruleset.Value);
                 var scoreProcessor = new OsuScoreProcessor();
                 scoreProcessor.ApplyBeatmap(playable);
@@ -96,10 +62,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 // For player 2, send frames in sets of 10.
                 for (int i = 0; i < 100; i++)
                 {
-                    spectatorClient.SendFrames(PLAYER_1_ID, i, 1);
+                    SpectatorClient.SendFrames(PLAYER_1_ID, 1);
 
                     if (i % 10 == 0)
-                        spectatorClient.SendFrames(PLAYER_2_ID, i, 10);
+                        SpectatorClient.SendFrames(PLAYER_2_ID, 10);
                 }
             });
 
@@ -145,17 +111,5 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         private void assertCombo(int userId, int expectedCombo)
             => AddUntilStep($"player {userId} has {expectedCombo} combo", () => this.ChildrenOfType<GameplayLeaderboardScore>().Single(s => s.User?.Id == userId).Combo.Value == expectedCombo);
-
-        private class TestUserLookupCache : UserLookupCache
-        {
-            protected override Task<User> ComputeValueAsync(int lookup, CancellationToken token = default)
-            {
-                return Task.FromResult(new User
-                {
-                    Id = lookup,
-                    Username = $"User {lookup}"
-                });
-            }
-        }
     }
 }

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

@@ -3,31 +3,20 @@
 
 using System.Collections.Generic;
 using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Testing;
 using osu.Game.Beatmaps;
-using osu.Game.Database;
-using osu.Game.Online.Spectator;
+using osu.Game.Rulesets.UI;
 using osu.Game.Screens.OnlinePlay.Multiplayer.Spectate;
 using osu.Game.Screens.Play;
 using osu.Game.Tests.Beatmaps.IO;
-using osu.Game.Tests.Visual.Spectator;
-using osu.Game.Users;
 
 namespace osu.Game.Tests.Visual.Multiplayer
 {
     public class TestSceneMultiSpectatorScreen : MultiplayerTestScene
     {
-        [Cached(typeof(SpectatorClient))]
-        private TestSpectatorClient spectatorClient = new TestSpectatorClient();
-
-        [Cached(typeof(UserLookupCache))]
-        private UserLookupCache lookupCache = new TestUserLookupCache();
-
         [Resolved]
         private OsuGameBase game { get; set; }
 
@@ -37,7 +26,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private MultiSpectatorScreen spectatorScreen;
 
         private readonly List<int> playingUserIds = new List<int>();
-        private readonly Dictionary<int, int> nextFrame = new Dictionary<int, int>();
 
         private BeatmapSetInfo importedSet;
         private BeatmapInfo importedBeatmap;
@@ -51,25 +39,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
             importedBeatmapId = importedBeatmap.OnlineBeatmapID ?? -1;
         }
 
-        public override void SetUpSteps()
-        {
-            base.SetUpSteps();
-
-            AddStep("reset sent frames", () => nextFrame.Clear());
-
-            AddStep("add streaming client", () =>
-            {
-                Remove(spectatorClient);
-                Add(spectatorClient);
-            });
-
-            AddStep("finish previous gameplay", () =>
-            {
-                foreach (var id in playingUserIds)
-                    spectatorClient.EndPlay(id);
-                playingUserIds.Clear();
-            });
-        }
+        [SetUp]
+        public new void Setup() => Schedule(() => playingUserIds.Clear());
 
         [Test]
         public void TestDelayedStart()
@@ -80,18 +51,16 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 Client.CurrentMatchPlayingUserIds.Add(PLAYER_2_ID);
                 playingUserIds.Add(PLAYER_1_ID);
                 playingUserIds.Add(PLAYER_2_ID);
-                nextFrame[PLAYER_1_ID] = 0;
-                nextFrame[PLAYER_2_ID] = 0;
             });
 
             loadSpectateScreen(false);
 
             AddWaitStep("wait a bit", 10);
-            AddStep("load player first_player_id", () => spectatorClient.StartPlay(PLAYER_1_ID, importedBeatmapId));
+            AddStep("load player first_player_id", () => SpectatorClient.StartPlay(PLAYER_1_ID, importedBeatmapId));
             AddUntilStep("one player added", () => spectatorScreen.ChildrenOfType<Player>().Count() == 1);
 
             AddWaitStep("wait a bit", 10);
-            AddStep("load player second_player_id", () => spectatorClient.StartPlay(PLAYER_2_ID, importedBeatmapId));
+            AddStep("load player second_player_id", () => SpectatorClient.StartPlay(PLAYER_2_ID, importedBeatmapId));
             AddUntilStep("two players added", () => spectatorScreen.ChildrenOfType<Player>().Count() == 2);
         }
 
@@ -107,6 +76,23 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddWaitStep("wait a bit", 20);
         }
 
+        [Test]
+        public void TestTimeDoesNotProgressWhileAllPlayersPaused()
+        {
+            start(new[] { PLAYER_1_ID, PLAYER_2_ID });
+            loadSpectateScreen();
+
+            sendFrames(PLAYER_1_ID, 40);
+            sendFrames(PLAYER_2_ID, 20);
+
+            checkPaused(PLAYER_2_ID, true);
+            checkPausedInstant(PLAYER_1_ID, false);
+            AddAssert("master clock still running", () => this.ChildrenOfType<MasterGameplayClockContainer>().Single().IsRunning);
+
+            checkPaused(PLAYER_1_ID, true);
+            AddUntilStep("master clock paused", () => !this.ChildrenOfType<MasterGameplayClockContainer>().Single().IsRunning);
+        }
+
         [Test]
         public void TestPlayersMustStartSimultaneously()
         {
@@ -151,7 +137,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             // Send initial frames for both players. A few more for player 1.
             sendFrames(PLAYER_1_ID, 20);
-            sendFrames(PLAYER_2_ID, 10);
+            sendFrames(PLAYER_2_ID);
             checkPausedInstant(PLAYER_1_ID, false);
             checkPausedInstant(PLAYER_2_ID, false);
 
@@ -182,7 +168,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             // Send initial frames for both players. A few more for player 1.
             sendFrames(PLAYER_1_ID, 1000);
-            sendFrames(PLAYER_2_ID, 10);
+            sendFrames(PLAYER_2_ID, 30);
             checkPausedInstant(PLAYER_1_ID, false);
             checkPausedInstant(PLAYER_2_ID, false);
 
@@ -208,10 +194,10 @@ namespace osu.Game.Tests.Visual.Multiplayer
             assertMuted(PLAYER_1_ID, true);
             assertMuted(PLAYER_2_ID, true);
 
-            sendFrames(PLAYER_1_ID, 10);
+            sendFrames(PLAYER_1_ID);
             sendFrames(PLAYER_2_ID, 20);
-            assertMuted(PLAYER_1_ID, false);
-            assertMuted(PLAYER_2_ID, true);
+            checkPaused(PLAYER_1_ID, false);
+            assertOneNotMuted();
 
             checkPaused(PLAYER_1_ID, true);
             assertMuted(PLAYER_1_ID, true);
@@ -229,6 +215,36 @@ namespace osu.Game.Tests.Visual.Multiplayer
             assertMuted(PLAYER_2_ID, true);
         }
 
+        [Test]
+        public void TestSpectatingDuringGameplay()
+        {
+            var players = new[] { PLAYER_1_ID, PLAYER_2_ID };
+
+            start(players);
+            sendFrames(players, 300);
+
+            loadSpectateScreen();
+            sendFrames(players, 300);
+
+            AddUntilStep("playing from correct point in time", () => this.ChildrenOfType<DrawableRuleset>().All(r => r.FrameStableClock.CurrentTime > 30000));
+        }
+
+        [Test]
+        public void TestSpectatingDuringGameplayWithLateFrames()
+        {
+            start(new[] { PLAYER_1_ID, PLAYER_2_ID });
+            sendFrames(new[] { PLAYER_1_ID, PLAYER_2_ID }, 300);
+
+            loadSpectateScreen();
+            sendFrames(PLAYER_1_ID, 300);
+
+            AddWaitStep("wait maximum start delay seconds", (int)(CatchUpSyncManager.MAXIMUM_START_DELAY / TimePerAction));
+            checkPaused(PLAYER_1_ID, false);
+
+            sendFrames(PLAYER_2_ID, 300);
+            AddUntilStep("player 2 playing from correct point in time", () => getPlayer(PLAYER_2_ID).ChildrenOfType<DrawableRuleset>().Single().FrameStableClock.CurrentTime > 30000);
+        }
+
         private void loadSpectateScreen(bool waitForPlayerLoad = true)
         {
             AddStep("load screen", () =>
@@ -242,8 +258,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddUntilStep("wait for screen load", () => spectatorScreen.LoadState == LoadState.Loaded && (!waitForPlayerLoad || spectatorScreen.AllPlayersLoaded));
         }
 
-        private void start(int userId, int? beatmapId = null) => start(new[] { userId }, beatmapId);
-
         private void start(int[] userIds, int? beatmapId = null)
         {
             AddStep("start play", () =>
@@ -251,23 +265,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 foreach (int id in userIds)
                 {
                     Client.CurrentMatchPlayingUserIds.Add(id);
-                    spectatorClient.StartPlay(id, beatmapId ?? importedBeatmapId);
+                    SpectatorClient.StartPlay(id, beatmapId ?? importedBeatmapId);
                     playingUserIds.Add(id);
-                    nextFrame[id] = 0;
                 }
             });
         }
 
-        private void finish(int userId)
-        {
-            AddStep("end play", () =>
-            {
-                spectatorClient.EndPlay(userId);
-                playingUserIds.Remove(userId);
-                nextFrame.Remove(userId);
-            });
-        }
-
         private void sendFrames(int userId, int count = 10) => sendFrames(new[] { userId }, count);
 
         private void sendFrames(int[] userIds, int count = 10)
@@ -275,10 +278,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddStep("send frames", () =>
             {
                 foreach (int id in userIds)
-                {
-                    spectatorClient.SendFrames(id, nextFrame[id], count);
-                    nextFrame[id] += count;
-                }
+                    SpectatorClient.SendFrames(id, count);
             });
         }
 
@@ -286,7 +286,14 @@ namespace osu.Game.Tests.Visual.Multiplayer
             => AddUntilStep($"{userId} is {(state ? "paused" : "playing")}", () => getPlayer(userId).ChildrenOfType<GameplayClockContainer>().First().GameplayClock.IsRunning != state);
 
         private void checkPausedInstant(int userId, bool state)
-            => AddAssert($"{userId} is {(state ? "paused" : "playing")}", () => getPlayer(userId).ChildrenOfType<GameplayClockContainer>().First().GameplayClock.IsRunning != state);
+        {
+            checkPaused(userId, state);
+
+            // Todo: The following should work, but is broken because SpectatorScreen retrieves the WorkingBeatmap via the BeatmapManager, bypassing the test scene clock and running real-time.
+            // AddAssert($"{userId} is {(state ? "paused" : "playing")}", () => getPlayer(userId).ChildrenOfType<GameplayClockContainer>().First().GameplayClock.IsRunning != state);
+        }
+
+        private void assertOneNotMuted() => AddAssert("one player not muted", () => spectatorScreen.ChildrenOfType<PlayerArea>().Count(p => !p.Mute) == 1);
 
         private void assertMuted(int userId, bool muted)
             => AddAssert($"{userId} {(muted ? "is" : "is not")} muted", () => getInstance(userId).Mute == muted);
@@ -297,17 +304,5 @@ namespace osu.Game.Tests.Visual.Multiplayer
         private Player getPlayer(int userId) => getInstance(userId).ChildrenOfType<Player>().Single();
 
         private PlayerArea getInstance(int userId) => spectatorScreen.ChildrenOfType<PlayerArea>().Single(p => p.UserId == userId);
-
-        internal class TestUserLookupCache : UserLookupCache
-        {
-            protected override Task<User> ComputeValueAsync(int lookup, CancellationToken token = default)
-            {
-                return Task.FromResult(new User
-                {
-                    Id = lookup,
-                    Username = $"User {lookup}"
-                });
-            }
-        }
     }
 }