Reduce warning/suggestion count to zero.

osu.Desktop.VisualTests/Tests/TestCasePlayer.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
 using System.Collections.Generic;
+using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Screens.Testing;
 using osu.Game.Beatmaps;
@@ -38,7 +39,7 @@ namespace osu.Desktop.VisualTests.Tests
 
             WorkingBeatmap beatmap = null;
 
-            var beatmapInfo = db.Query<BeatmapInfo>().Where(b => b.Mode == PlayMode.Osu).FirstOrDefault();
+            var beatmapInfo = db.Query<BeatmapInfo>().FirstOrDefault(b => b.Mode == PlayMode.Osu);
             if (beatmapInfo != null)
                 beatmap = db.GetWorkingBeatmap(beatmapInfo);
 

osu.Desktop.VisualTests/Tests/TestCaseReplay.cs

@@ -3,11 +3,8 @@
 
 using System;
 using System.IO;
-using osu.Framework.Allocation;
 using osu.Framework.Input.Handlers;
-using osu.Framework.Platform;
 using osu.Game.Beatmaps;
-using osu.Game.Database;
 using osu.Game.Modes;
 using osu.Game.Screens.Play;
 
@@ -20,16 +17,9 @@ namespace osu.Desktop.VisualTests.Tests
         private InputHandler replay;
 
         private Func<Stream> getReplayStream;
-        private ScoreDatabase scoreDatabase;
 
         public override string Description => @"Testing replay playback.";
 
-        [BackgroundDependencyLoader]
-        private void load(Storage storage)
-        {
-            scoreDatabase = new ScoreDatabase(storage);
-        }
-
         protected override Player CreatePlayer(WorkingBeatmap beatmap)
         {
             var player = base.CreatePlayer(beatmap);

osu.Desktop/Overlays/VersionManager.cs

@@ -189,7 +189,7 @@ namespace osu.Desktop.Overlays
 
         private class UpdateProgressNotification : ProgressNotification
         {
-            protected override Notification CreateCompletionNotification() => new ProgressCompletionNotification(this)
+            protected override Notification CreateCompletionNotification() => new ProgressCompletionNotification()
             {
                 Text = @"Update ready to install. Click to restart!",
                 Activated = () =>

osu.Game.Modes.Osu/Objects/Drawables/DrawableSlider.cs

@@ -24,10 +24,11 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
         private SliderBody body;
         private SliderBall ball;
 
-        private SliderBouncer bouncer1, bouncer2;
+        private SliderBouncer bouncer2;
 
         public DrawableSlider(Slider s) : base(s)
         {
+            SliderBouncer bouncer1;
             slider = s;
 
             Children = new Drawable[]
@@ -124,8 +125,8 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
 
         protected override void CheckJudgement(bool userTriggered)
         {
-            var j = Judgement as OsuJudgementInfo;
+            var j = (OsuJudgementInfo)Judgement;
-            var sc = initialCircle.Judgement as OsuJudgementInfo;
+            var sc = (OsuJudgementInfo)initialCircle.Judgement;
 
             if (!userTriggered && Time.Current >= HitObject.EndTime)
             {

osu.Game.Modes.Osu/OsuAutoReplay.cs

@@ -65,12 +65,13 @@ namespace osu.Game.Modes.Osu
         private double applyModsToTime(double v) => v;
         private double applyModsToRate(double v) => v;
 
+        public bool DelayedMovements; // ModManager.CheckActive(Mods.Relax2);
+
         private void createAutoReplay()
         {
             int buttonIndex = 0;
 
-            bool delayedMovements = false;// ModManager.CheckActive(Mods.Relax2);
+            EasingTypes preferredEasing = DelayedMovements ? EasingTypes.InOutCubic : EasingTypes.Out;
-            EasingTypes preferredEasing = delayedMovements ? EasingTypes.InOutCubic : EasingTypes.Out;
 
             addFrameToReplay(new LegacyReplayFrame(-100000, 256, 500, LegacyButtonState.None));
             addFrameToReplay(new LegacyReplayFrame(beatmap.HitObjects[0].StartTime - 1500, 256, 500, LegacyButtonState.None));
@@ -85,7 +86,7 @@ namespace osu.Game.Modes.Osu
 
             for (int i = 0; i < beatmap.HitObjects.Count; i++)
             {
-                OsuHitObject h = beatmap.HitObjects[i] as OsuHitObject;
+                OsuHitObject h = (OsuHitObject)beatmap.HitObjects[i];
 
                 //if (h.EndTime < InputManager.ReplayStartTime)
                 //{
@@ -95,9 +96,9 @@ namespace osu.Game.Modes.Osu
 
                 int endDelay = h is Spinner ? 1 : 0;
 
-                if (delayedMovements && i > 0)
+                if (DelayedMovements && i > 0)
                 {
-                    OsuHitObject last = beatmap.HitObjects[i - 1] as OsuHitObject;
+                    OsuHitObject last = (OsuHitObject)beatmap.HitObjects[i - 1];
 
                     //Make the cursor stay at a hitObject as long as possible (mainly for autopilot).
                     if (h.StartTime - h.HitWindowFor(OsuScoreResult.Miss) > last.EndTime + h.HitWindowFor(OsuScoreResult.Hit50) + 50)

osu.Game/Database/ScoreDatabase.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.IO;
+using System.Linq;
 using osu.Framework.Platform;
 using osu.Game.IO.Legacy;
 using osu.Game.IPC;
@@ -18,6 +19,7 @@ namespace osu.Game.Database
 
         private const string replay_folder = @"replays";
 
+        // ReSharper disable once NotAccessedField.Local (we should keep a reference to this so it is not finalised)
         private ScoreIPCChannel ipc;
 
         public ScoreDatabase(Storage storage, IIpcHost importHost = null, BeatmapDatabase beatmaps = null)
@@ -45,7 +47,7 @@ namespace osu.Game.Database
                 var version = sr.ReadInt32();
                 /* score.FileChecksum = */
                 var beatmapHash = sr.ReadString();
-                score.Beatmap = beatmaps.Query<BeatmapInfo>().Where(b => b.Hash == beatmapHash).FirstOrDefault();
+                score.Beatmap = beatmaps.Query<BeatmapInfo>().FirstOrDefault(b => b.Hash == beatmapHash);
                 /* score.PlayerName = */
                 sr.ReadString();
                 /* var localScoreChecksum = */

osu.Game/IO/Legacy/SerializationReader.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Reflection;
 using System.Runtime.Serialization;
@@ -184,6 +185,9 @@ namespace osu.Game.IO.Legacy
             {
                 if (formatter == null)
                     initialize();
+
+                Debug.Assert(formatter != null, "formatter != null");
+
                 return formatter.Deserialize(stream);
             }
 
@@ -203,46 +207,39 @@ namespace osu.Game.IO.Legacy
                     List<Type> tmpTypes = new List<Type>();
                     Type genType = null;
 
-                    try
+                    if (typeName.Contains("System.Collections.Generic") && typeName.Contains("[["))
                     {
-                        if (typeName.Contains("System.Collections.Generic") && typeName.Contains("[["))
+                        string[] splitTyps = typeName.Split('[');
-                        {
-                            string[] splitTyps = typeName.Split('[');
 
-                            foreach (string typ in splitTyps)
+                        foreach (string typ in splitTyps)
+                        {
+                            if (typ.Contains("Version"))
                             {
-                                if (typ.Contains("Version"))
+                                string asmTmp = typ.Substring(typ.IndexOf(',') + 1);
-                                {
+                                string asmName = asmTmp.Remove(asmTmp.IndexOf(']')).Trim();
-                                    string asmTmp = typ.Substring(typ.IndexOf(',') + 1);
+                                string typName = typ.Remove(typ.IndexOf(','));
-                                    string asmName = asmTmp.Remove(asmTmp.IndexOf(']')).Trim();
+                                tmpTypes.Add(BindToType(asmName, typName));
-                                    string typName = typ.Remove(typ.IndexOf(','));
-                                    tmpTypes.Add(BindToType(asmName, typName));
-                                }
-                                else if (typ.Contains("Generic"))
-                                {
-                                    genType = BindToType(assemblyName, typ);
-                                }
                             }
-                            if (genType != null && tmpTypes.Count > 0)
+                            else if (typ.Contains("Generic"))
                             {
-                                return genType.MakeGenericType(tmpTypes.ToArray());
+                                genType = BindToType(assemblyName, typ);
                             }
                         }
-
+                        if (genType != null && tmpTypes.Count > 0)
-                        string toAssemblyName = assemblyName.Split(',')[0];
-                        Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
-                        foreach (Assembly a in assemblies)
                         {
-                            if (a.FullName.Split(',')[0] == toAssemblyName)
+                            return genType.MakeGenericType(tmpTypes.ToArray());
-                            {
-                                typeToDeserialize = a.GetType(typeName);
-                                break;
-                            }
                         }
                     }
-                    catch (Exception exception)
+
+                    string toAssemblyName = assemblyName.Split(',')[0];
+                    Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
+                    foreach (Assembly a in assemblies)
                     {
-                        throw exception;
+                        if (a.FullName.Split(',')[0] == toAssemblyName)
+                        {
+                            typeToDeserialize = a.GetType(typeName);
+                            break;
+                        }
                     }
 
                     cache.Add(assemblyName + typeName, typeToDeserialize);

osu.Game/IO/Legacy/SerializationWriter.cs

@@ -8,6 +8,8 @@ using System.Runtime.Serialization;
 using System.Runtime.Serialization.Formatters;
 using System.Runtime.Serialization.Formatters.Binary;
 using System.Text;
+// ReSharper disable ConditionIsAlwaysTrueOrFalse (we're allowing nulls to be passed to the writer where the underlying class doesn't).
+// ReSharper disable HeuristicUnreachableCode
 
 namespace osu.Game.IO.Legacy
 {

osu.Game/IPC/BeatmapIPCChannel.cs

@@ -19,7 +19,10 @@ namespace osu.Game.IPC
             MessageReceived += msg =>
             {
                 Debug.Assert(beatmaps != null);
-                ImportAsync(msg.Path);
+                ImportAsync(msg.Path).ContinueWith(t =>
+                {
+                    if (t.Exception != null) throw t.Exception;
+                }, TaskContinuationOptions.OnlyOnFaulted);
             };
         }
 

osu.Game/Modes/Objects/Drawables/DrawableHitObject.cs

@@ -129,10 +129,13 @@ namespace osu.Game.Modes.Objects.Drawables
         [BackgroundDependencyLoader]
         private void load(AudioManager audio)
         {
-            string hitType = ((HitObject.Sample?.Type ?? SampleType.None) == SampleType.None ? SampleType.Normal : HitObject.Sample.Type).ToString().ToLower();
+            SampleType type = HitObject.Sample?.Type ?? SampleType.None;
-            string sampleSet = (HitObject.Sample?.Set ?? SampleSet.Normal).ToString().ToLower();
+            if (type == SampleType.None)
+                type = SampleType.Normal;
 
-            Sample = audio.Sample.Get($@"Gameplay/{sampleSet}-hit{hitType}");
+            SampleSet sampleSet = HitObject.Sample?.Set ?? SampleSet.Normal;
+
+            Sample = audio.Sample.Get($@"Gameplay/{sampleSet.ToString().ToLower()}-hit{type.ToString().ToLower()}");
         }
 
         private List<DrawableHitObject<HitObjectType>> nestedHitObjects;

osu.Game/OsuGameBase.cs

@@ -50,6 +50,7 @@ namespace osu.Game
         {
             get
             {
+                // ReSharper disable once RedundantAssignment
                 bool isDebug = false;
                 // Debug.Assert conditions are only evaluated in debug mode
                 Debug.Assert(isDebug = true);

osu.Game/Overlays/MusicController.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Threading.Tasks;
 using OpenTK;
 using OpenTK.Graphics;
@@ -30,7 +31,7 @@ namespace osu.Game.Overlays
     {
         private MusicControllerBackground backgroundSprite;
         private DragBar progress;
-        private TextAwesome playButton, listButton;
+        private TextAwesome playButton;
         private SpriteText title, artist;
 
         private List<BeatmapSetInfo> playList;
@@ -59,6 +60,8 @@ namespace osu.Game.Overlays
 
         protected override bool OnDrag(InputState state)
         {
+            Trace.Assert(state.Mouse.PositionMouseDown != null, "state.Mouse.PositionMouseDown != null");
+
             Vector2 change = state.Mouse.Position - state.Mouse.PositionMouseDown.Value;
 
             // Diminish the drag distance as we go further to simulate "rubber band" feeling.
@@ -187,7 +190,7 @@ namespace osu.Game.Overlays
                             Position = new Vector2(20, -30),
                             Children = new Drawable[]
                             {
-                                listButton = new TextAwesome
+                                new TextAwesome
                                 {
                                     TextSize = 15,
                                     Icon = FontAwesome.fa_bars,

osu.Game/Overlays/Notifications/ProgressCompletionNotification.cs

@@ -10,11 +10,8 @@ namespace osu.Game.Overlays.Notifications
 {
     public class ProgressCompletionNotification : SimpleNotification
     {
-        private ProgressNotification progressNotification;
+        public ProgressCompletionNotification()
-
-        public ProgressCompletionNotification(ProgressNotification progressNotification)
         {
-            this.progressNotification = progressNotification;
             Icon = FontAwesome.fa_check;
         }
 

osu.Game/Overlays/Notifications/ProgressNotification.cs

@@ -90,7 +90,7 @@ namespace osu.Game.Overlays.Notifications
 
         private ProgressNotificationState state;
 
-        protected virtual Notification CreateCompletionNotification() => new ProgressCompletionNotification(this)
+        protected virtual Notification CreateCompletionNotification() => new ProgressCompletionNotification()
         {
             Activated = CompletionClickAction,
             Text = $"Task \"{Text}\" has completed!"

osu.Game/Overlays/Notifications/SimpleNotification.cs

@@ -81,10 +81,8 @@ namespace osu.Game.Overlays.Notifications
 
             set
             {
-                if (base.Read = value)
+                base.Read = value;
-                    Light.FadeOut(100);
+                Light.FadeTo(value ? 1 : 0, 100);
-                else
-                    Light.FadeIn(100);
             }
         }
     }

osu.Game/Overlays/OptionsOverlay.cs

@@ -147,11 +147,8 @@ namespace osu.Game.Overlays
 
                 var previous = sidebarButtons.SingleOrDefault(sb => sb.Selected);
                 var next = sidebarButtons.SingleOrDefault(sb => sb.Section == bestCandidate);
-                if (next != null)
+                if (next != null) next.Selected = true;
-                {
+                if (previous != null) previous.Selected = false;
-                    previous.Selected = false;
-                    next.Selected = true;
-                }
             }
         }
 

osu.Game/Overlays/Toolbar/Toolbar.cs

@@ -30,7 +30,7 @@ namespace osu.Game.Overlays.Toolbar
 
         protected override bool BlockPassThroughInput => false;
 
-        private const int transition_time = 500;
+        private const double transition_time = 500;
 
         private const float alpha_hovering = 0.8f;
         private const float alpha_normal = 0.6f;

osu.Game/Screens/GameScreenWhiteBox.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Screens
     {
         private BackButton popButton;
 
-        private const int transition_time = 1000;
+        private const double transition_time = 1000;
 
         protected virtual IEnumerable<Type> PossibleChildren => null;
 

osu.Game/Screens/Menu/Button.cs

@@ -28,16 +28,11 @@ namespace osu.Game.Screens.Menu
     {
         private Container iconText;
         private Container box;
-        private Box boxColourLayer;
         private Box boxHoverLayer;
-        private Color4 colour;
         private TextAwesome icon;
         private string internalName;
-        private readonly FontAwesome symbol;
         private Action clickAction;
-        private readonly float extraWidth;
         private Key triggerKey;
-        private string text;
         private SampleChannel sampleClick;
 
         public override bool Contains(Vector2 screenSpacePos)
@@ -48,12 +43,8 @@ namespace osu.Game.Screens.Menu
         public Button(string text, string internalName, FontAwesome symbol, Color4 colour, Action clickAction = null, float extraWidth = 0, Key triggerKey = Key.Unknown)
         {
             this.internalName = internalName;
-            this.symbol = symbol;
-            this.colour = colour;
             this.clickAction = clickAction;
-            this.extraWidth = extraWidth;
             this.triggerKey = triggerKey;
-            this.text = text;
 
             AutoSizeAxes = Axes.Both;
             Alpha = 0;
@@ -80,7 +71,7 @@ namespace osu.Game.Screens.Menu
                     Shear = new Vector2(ButtonSystem.WEDGE_WIDTH / boxSize.Y, 0),
                     Children = new []
                     {
-                        boxColourLayer = new Box
+                        new Box
                         {
                             EdgeSmoothness = new Vector2(1.5f, 0),
                             RelativeSizeAxes = Axes.Both,
@@ -321,12 +312,12 @@ namespace osu.Game.Screens.Menu
                     case ButtonState.Expanded:
                         const int expand_duration = 500;
                         box.ScaleTo(new Vector2(1, 1), expand_duration, EasingTypes.OutExpo);
-                        FadeIn(expand_duration / 6);
+                        FadeIn(expand_duration / 6f);
                         break;
                     case ButtonState.Exploded:
                         const int explode_duration = 200;
                         box.ScaleTo(new Vector2(2, 1), explode_duration, EasingTypes.OutExpo);
-                        FadeOut(explode_duration / 4 * 3);
+                        FadeOut(explode_duration / 4f * 3);
                         break;
                 }
             }

osu.Game/Screens/Play/Player.cs

@@ -81,6 +81,9 @@ namespace osu.Game.Screens.Play
 
                 if ((Beatmap?.Beatmap?.HitObjects.Count ?? 0) == 0)
                     throw new Exception("No valid objects were found!");
+
+                if (Beatmap == null)
+                    throw new Exception("Beatmap was not loaded");
             }
             catch (Exception e)
             {

osu.Game/Screens/Play/PlayerLoader.cs

@@ -167,7 +167,7 @@ namespace osu.Game.Screens.Play
                                 {
                                     new Sprite
                                     {
-                                        Texture = beatmap.Background,
+                                        Texture = beatmap?.Background,
                                         Origin = Anchor.Centre,
                                         Anchor = Anchor.Centre,
                                         FillMode = FillMode.Fill,
@@ -176,7 +176,7 @@ namespace osu.Game.Screens.Play
                             },
                             new OsuSpriteText
                             {
-                                Text = beatmap.BeatmapInfo?.Version,
+                                Text = beatmap?.BeatmapInfo?.Version,
                                 TextSize = 26,
                                 Font = @"Exo2.0-MediumItalic",
                                 Origin = Anchor.TopCentre,

osu.Game/Screens/Tournament/ScrollingTeamContainer.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
@@ -109,7 +110,11 @@ namespace osu.Game.Screens.Tournament
                         break;
                     case ScrollState.Stopped:
                         // Find closest to center
+                        if (!Children.Any())
+                            break;
+
                         Drawable closest = null;
+
                         foreach (var c in Children)
                         {
                             if (!(c is ScrollingTeam))
@@ -128,6 +133,8 @@ namespace osu.Game.Screens.Tournament
                                 closest = c;
                         }
 
+                        Trace.Assert(closest != null, "closest != null");
+
                         offset += DrawWidth / 2f - (closest.Position.X + closest.DrawWidth / 2f);
 
                         ScrollingTeam st = closest as ScrollingTeam;
@@ -310,7 +317,7 @@ namespace osu.Game.Screens.Tournament
             public override void Apply(Drawable d)
             {
                 base.Apply(d);
-                (d as ScrollingTeamContainer).speed = CurrentValue;
+                ((ScrollingTeamContainer)d).speed = CurrentValue;
             }
         }