Merge pull request #24409 from cdwcgt/tournament-nullable

Remove #nullable disable in tournament

osu.Game.Tournament.Tests/Components/TestSceneDateTextBox.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using NUnit.Framework;
 using osu.Game.Tests.Visual;
 using osu.Game.Tournament.Components;
@@ -13,7 +11,7 @@ namespace osu.Game.Tournament.Tests.Components
 {
     public partial class TestSceneDateTextBox : OsuManualInputManagerTestScene
     {
-        private DateTextBox textBox;
+        private DateTextBox textBox = null!;
 
         [SetUp]
         public void Setup() => Schedule(() =>

osu.Game.Tournament.Tests/Components/TestSceneSongBar.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using NUnit.Framework;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
@@ -22,7 +20,7 @@ namespace osu.Game.Tournament.Tests.Components
         [Test]
         public void TestSongBar()
         {
-            SongBar songBar = null;
+            SongBar songBar = null!;
 
             AddStep("create bar", () => Child = songBar = new SongBar
             {

osu.Game.Tournament.Tests/Components/TestSceneTournamentModDisplay.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -19,12 +17,12 @@ namespace osu.Game.Tournament.Tests.Components
     public partial class TestSceneTournamentModDisplay : TournamentTestScene
     {
         [Resolved]
-        private IAPIProvider api { get; set; }
+        private IAPIProvider api { get; set; } = null!;
 
         [Resolved]
-        private IRulesetStore rulesets { get; set; }
+        private IRulesetStore rulesets { get; set; } = null!;
 
-        private FillFlowContainer<TournamentBeatmapPanel> fillFlow;
+        private FillFlowContainer<TournamentBeatmapPanel> fillFlow = null!;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -45,7 +43,7 @@ namespace osu.Game.Tournament.Tests.Components
 
         private void success(APIBeatmap beatmap)
         {
-            var ruleset = rulesets.GetRuleset(Ladder.Ruleset.Value.OnlineID);
+            var ruleset = rulesets.GetRuleset(Ladder.Ruleset.Value?.OnlineID ?? -1);
 
             if (ruleset == null)
                 return;

osu.Game.Tournament.Tests/NonVisual/DataLoadTest.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.IO;
 using System.Threading.Tasks;
@@ -81,11 +79,11 @@ namespace osu.Game.Tournament.Tests.NonVisual
         public partial class TestTournament : TournamentGameBase
         {
             private readonly bool resetRuleset;
-            private readonly Action runOnLoadComplete;
+            private readonly Action? runOnLoadComplete;
 
             public new Task BracketLoadTask => base.BracketLoadTask;
 
-            public TestTournament(bool resetRuleset = false, [InstantHandle] Action runOnLoadComplete = null)
+            public TestTournament(bool resetRuleset = false, [InstantHandle] Action? runOnLoadComplete = null)
             {
                 this.resetRuleset = resetRuleset;
                 this.runOnLoadComplete = runOnLoadComplete;

osu.Game.Tournament.Tests/NonVisual/IPCLocationTest.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.IO;
 using System.Linq;
 using NUnit.Framework;
@@ -36,11 +34,11 @@ namespace osu.Game.Tournament.Tests.NonVisual
                 {
                     var osu = LoadTournament(host);
                     TournamentStorage storage = (TournamentStorage)osu.Dependencies.Get<Storage>();
-                    FileBasedIPC ipc = null;
+                    FileBasedIPC? ipc = null;
 
                     WaitForOrAssert(() => (ipc = osu.Dependencies.Get<MatchIPCInfo>() as FileBasedIPC)?.IsLoaded == true, @"ipc could not be populated in a reasonable amount of time");
 
-                    Assert.True(ipc.SetIPCLocation(testStableInstallDirectory));
+                    Assert.True(ipc!.SetIPCLocation(testStableInstallDirectory));
                     Assert.True(storage.AllTournaments.Exists("stable.json"));
                 }
                 finally

osu.Game.Tournament.Tests/NonVisual/LadderInfoSerialisationTest.cs

@@ -35,8 +35,8 @@ namespace osu.Game.Tournament.Tests.NonVisual
                 PlayersPerTeam = { Value = 4 },
                 Teams =
                 {
-                    match.Team1.Value,
+                    match.Team1.Value!,
-                    match.Team2.Value,
+                    match.Team2.Value!,
                 },
                 Rounds =
                 {

osu.Game.Tournament.Tests/NonVisual/TournamentHostTest.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Threading;
 using System.Threading.Tasks;
@@ -13,7 +11,7 @@ namespace osu.Game.Tournament.Tests.NonVisual
 {
     public abstract class TournamentHostTest
     {
-        public static TournamentGameBase LoadTournament(GameHost host, TournamentGameBase tournament = null)
+        public static TournamentGameBase LoadTournament(GameHost host, TournamentGameBase? tournament = null)
         {
             tournament ??= new TournamentGameBase();
             Task.Factory.StartNew(() => host.Run(tournament), TaskCreationOptions.LongRunning)

osu.Game.Tournament.Tests/Screens/TestSceneGameplayScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;

osu.Game.Tournament.Tests/Screens/TestSceneLadderEditorScreen.cs

@@ -94,7 +94,7 @@ namespace osu.Game.Tournament.Tests.Screens
 
             AddStep("release mouse button", () => InputManager.ReleaseButton(MouseButton.Left));
 
-            AddAssert("assert ladder teams reset", () => Ladder.CurrentMatch.Value.Team1.Value == null && Ladder.CurrentMatch.Value.Team2.Value == null);
+            AddAssert("assert ladder teams reset", () => Ladder.CurrentMatch.Value?.Team1.Value == null && Ladder.CurrentMatch.Value?.Team2.Value == null);
         }
     }
 }

osu.Game.Tournament.Tests/Screens/TestSceneMapPoolScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Allocation;
@@ -16,7 +14,7 @@ namespace osu.Game.Tournament.Tests.Screens
 {
     public partial class TestSceneMapPoolScreen : TournamentScreenTestScene
     {
-        private MapPoolScreen screen;
+        private MapPoolScreen screen = null!;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -32,7 +30,7 @@ namespace osu.Game.Tournament.Tests.Screens
         {
             AddStep("load few maps", () =>
             {
-                Ladder.CurrentMatch.Value.Round.Value.Beatmaps.Clear();
+                Ladder.CurrentMatch.Value!.Round.Value!.Beatmaps.Clear();
 
                 for (int i = 0; i < 8; i++)
                     addBeatmap();
@@ -52,7 +50,7 @@ namespace osu.Game.Tournament.Tests.Screens
         {
             AddStep("load just enough maps", () =>
             {
-                Ladder.CurrentMatch.Value.Round.Value.Beatmaps.Clear();
+                Ladder.CurrentMatch.Value!.Round.Value!.Beatmaps.Clear();
 
                 for (int i = 0; i < 18; i++)
                     addBeatmap();
@@ -72,7 +70,7 @@ namespace osu.Game.Tournament.Tests.Screens
         {
             AddStep("load many maps", () =>
             {
-                Ladder.CurrentMatch.Value.Round.Value.Beatmaps.Clear();
+                Ladder.CurrentMatch.Value!.Round.Value!.Beatmaps.Clear();
 
                 for (int i = 0; i < 19; i++)
                     addBeatmap();
@@ -92,7 +90,7 @@ namespace osu.Game.Tournament.Tests.Screens
         {
             AddStep("load many maps", () =>
             {
-                Ladder.CurrentMatch.Value.Round.Value.Beatmaps.Clear();
+                Ladder.CurrentMatch.Value!.Round.Value!.Beatmaps.Clear();
 
                 for (int i = 0; i < 11; i++)
                     addBeatmap(i > 4 ? Ruleset.Value.CreateInstance().AllMods.ElementAt(i).Acronym : "NM");
@@ -118,7 +116,7 @@ namespace osu.Game.Tournament.Tests.Screens
         {
             AddStep("load many maps", () =>
             {
-                Ladder.CurrentMatch.Value.Round.Value.Beatmaps.Clear();
+                Ladder.CurrentMatch.Value!.Round.Value!.Beatmaps.Clear();
 
                 for (int i = 0; i < 12; i++)
                     addBeatmap(i > 4 ? Ruleset.Value.CreateInstance().AllMods.ElementAt(i).Acronym : "NM");
@@ -138,7 +136,7 @@ namespace osu.Game.Tournament.Tests.Screens
         {
             AddStep("load many maps", () =>
             {
-                Ladder.CurrentMatch.Value.Round.Value.Beatmaps.Clear();
+                Ladder.CurrentMatch.Value!.Round.Value!.Beatmaps.Clear();
 
                 for (int i = 0; i < 12; i++)
                     addBeatmap(i > 4 ? Ruleset.Value.CreateInstance().AllMods.ElementAt(i).Acronym : "NM");
@@ -155,7 +153,7 @@ namespace osu.Game.Tournament.Tests.Screens
 
         private void addBeatmap(string mods = "NM")
         {
-            Ladder.CurrentMatch.Value.Round.Value.Beatmaps.Add(new RoundBeatmap
+            Ladder.CurrentMatch.Value!.Round.Value!.Beatmaps.Add(new RoundBeatmap
             {
                 Beatmap = CreateSampleBeatmap(),
                 Mods = mods

osu.Game.Tournament.Tests/Screens/TestSceneScheduleScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using NUnit.Framework;
 using osu.Framework.Allocation;

osu.Game.Tournament.Tests/Screens/TestSceneSeedingEditorScreen.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using osu.Framework.Allocation;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Game.Tournament.Models;
 using osu.Game.Tournament.Screens.Editors;
 
@@ -17,7 +18,7 @@ namespace osu.Game.Tournament.Tests.Screens
         {
             var match = CreateSampleMatch();
 
-            Add(new SeedingEditorScreen(match.Team1.Value, new TeamEditorScreen())
+            Add(new SeedingEditorScreen(match.Team1.Value.AsNonNull(), new TeamEditorScreen())
             {
                 Width = 0.85f // create room for control panel
             });

osu.Game.Tournament.Tests/Screens/TestSceneTeamWinScreen.cs

@@ -17,7 +17,7 @@ namespace osu.Game.Tournament.Tests.Screens
             {
                 var match = Ladder.CurrentMatch.Value!;
 
-                match.Round.Value = Ladder.Rounds.FirstOrDefault(g => g.Name.Value == "Finals");
+                match.Round.Value = Ladder.Rounds.First(g => g.Name.Value == "Quarterfinals");
                 match.Completed.Value = true;
             });
 

osu.Game.Tournament.Tests/TournamentTestScene.cs

@@ -40,10 +40,10 @@ namespace osu.Game.Tournament.Tests
 
             match = CreateSampleMatch();
 
-            Ladder.Rounds.Add(match.Round.Value);
+            Ladder.Rounds.Add(match.Round.Value!);
             Ladder.Matches.Add(match);
-            Ladder.Teams.Add(match.Team1.Value);
+            Ladder.Teams.Add(match.Team1.Value!);
-            Ladder.Teams.Add(match.Team2.Value);
+            Ladder.Teams.Add(match.Team2.Value!);
 
             Ruleset.BindTo(Ladder.Ruleset);
             Dependencies.CacheAs(new StableInfo(storage));
@@ -152,7 +152,7 @@ namespace osu.Game.Tournament.Tests
             },
             Round =
             {
-                Value = new TournamentRound { Name = { Value = "Quarterfinals" } }
+                Value = new TournamentRound { Name = { Value = "Quarterfinals" } },
             }
         };
 

osu.Game.Tournament/Components/DrawableTeamFlag.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -17,14 +15,14 @@ namespace osu.Game.Tournament.Components
 {
     public partial class DrawableTeamFlag : Container
     {
-        private readonly TournamentTeam team;
+        private readonly TournamentTeam? team;
 
         [UsedImplicitly]
-        private Bindable<string> flag;
+        private Bindable<string>? flag;
 
-        private Sprite flagSprite;
+        private Sprite? flagSprite;
 
-        public DrawableTeamFlag(TournamentTeam team)
+        public DrawableTeamFlag(TournamentTeam? team)
         {
             this.team = team;
         }

osu.Game.Tournament/Components/DrawableTeamTitle.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -12,12 +10,12 @@ namespace osu.Game.Tournament.Components
 {
     public partial class DrawableTeamTitle : TournamentSpriteTextWithBackground
     {
-        private readonly TournamentTeam team;
+        private readonly TournamentTeam? team;
 
         [UsedImplicitly]
-        private Bindable<string> acronym;
+        private Bindable<string>? acronym;
 
-        public DrawableTeamTitle(TournamentTeam team)
+        public DrawableTeamTitle(TournamentTeam? team)
         {
             this.team = team;
         }

osu.Game.Tournament/Components/DrawableTournamentTeam.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -14,15 +12,15 @@ namespace osu.Game.Tournament.Components
 {
     public abstract partial class DrawableTournamentTeam : CompositeDrawable
     {
-        public readonly TournamentTeam Team;
+        public readonly TournamentTeam? Team;
 
         protected readonly Container Flag;
         protected readonly TournamentSpriteText AcronymText;
 
         [UsedImplicitly]
-        private Bindable<string> acronym;
+        private Bindable<string>? acronym;
 
-        protected DrawableTournamentTeam(TournamentTeam team)
+        protected DrawableTournamentTeam(TournamentTeam? team)
         {
             Team = team;
 
@@ -36,7 +34,8 @@ namespace osu.Game.Tournament.Components
         [BackgroundDependencyLoader]
         private void load()
         {
-            if (Team == null) return;
+            if (Team == null)
+                return;
 
             (acronym = Team.Acronym.GetBoundCopy()).BindValueChanged(_ => AcronymText.Text = Team?.Acronym.Value?.ToUpperInvariant() ?? string.Empty, true);
         }

osu.Game.Tournament/Components/SongBar.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -24,14 +22,14 @@ namespace osu.Game.Tournament.Components
 {
     public partial class SongBar : CompositeDrawable
     {
-        private TournamentBeatmap beatmap;
+        private TournamentBeatmap? beatmap;
 
         public const float HEIGHT = 145 / 2f;
 
         [Resolved]
-        private IBindable<RulesetInfo> ruleset { get; set; }
+        private IBindable<RulesetInfo> ruleset { get; set; } = null!;
 
-        public TournamentBeatmap Beatmap
+        public TournamentBeatmap? Beatmap
         {
             set
             {
@@ -55,7 +53,7 @@ namespace osu.Game.Tournament.Components
             }
         }
 
-        private FillFlowContainer flow;
+        private FillFlowContainer flow = null!;
 
         private bool expanded;
 

osu.Game.Tournament/Components/TournamentBeatmapPanel.cs

@@ -146,7 +146,12 @@ namespace osu.Game.Tournament.Components
 
         private void updateState()
         {
-            var newChoice = currentMatch.Value?.PicksBans.FirstOrDefault(p => p.BeatmapID == Beatmap?.OnlineID);
+            if (currentMatch.Value == null)
+            {
+                return;
+            }
+
+            var newChoice = currentMatch.Value.PicksBans.FirstOrDefault(p => p.BeatmapID == Beatmap?.OnlineID);
 
             bool shouldFlash = newChoice != choice;
 

osu.Game.Tournament/Components/TournamentMatchChatDisplay.cs

@@ -92,9 +92,9 @@ namespace osu.Game.Tournament.Components
             {
                 if (info.CurrentMatch.Value is TournamentMatch match)
                 {
-                    if (match.Team1.Value.Players.Any(u => u.OnlineID == Message.Sender.OnlineID))
+                    if (match.Team1.Value?.Players.Any(u => u.OnlineID == Message.Sender.OnlineID) == true)
                         UsernameColour = TournamentGame.COLOUR_RED;
-                    else if (match.Team2.Value.Players.Any(u => u.OnlineID == Message.Sender.OnlineID))
+                    else if (match.Team2.Value?.Players.Any(u => u.OnlineID == Message.Sender.OnlineID) == true)
                         UsernameColour = TournamentGame.COLOUR_BLUE;
                 }
             }

osu.Game.Tournament/Components/TourneyVideo.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Colour;
@@ -19,8 +17,8 @@ namespace osu.Game.Tournament.Components
     {
         private readonly string filename;
         private readonly bool drawFallbackGradient;
-        private Video video;
+        private Video? video;
-        private ManualClock manualClock;
+        private ManualClock? manualClock;
 
         public bool VideoAvailable => video != null;
 

osu.Game.Tournament/IPC/FileBasedIPC.cs

@@ -1,12 +1,9 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.IO;
 using System.Linq;
-using JetBrains.Annotations;
 using Microsoft.Win32;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions.ObjectExtensions;
@@ -24,36 +21,35 @@ namespace osu.Game.Tournament.IPC
 {
     public partial class FileBasedIPC : MatchIPCInfo
     {
-        public Storage IPCStorage { get; private set; }
+        public Storage? IPCStorage { get; private set; }
 
         [Resolved]
-        protected IAPIProvider API { get; private set; }
+        protected IAPIProvider API { get; private set; } = null!;
 
         [Resolved]
-        protected IRulesetStore Rulesets { get; private set; }
+        protected IRulesetStore Rulesets { get; private set; } = null!;
 
         [Resolved]
-        private GameHost host { get; set; }
+        private GameHost host { get; set; } = null!;
 
         [Resolved]
-        private LadderInfo ladder { get; set; }
+        private LadderInfo ladder { get; set; } = null!;
 
         [Resolved]
-        private StableInfo stableInfo { get; set; }
+        private StableInfo stableInfo { get; set; } = null!;
 
         private int lastBeatmapId;
-        private ScheduledDelegate scheduled;
+        private ScheduledDelegate? scheduled;
-        private GetBeatmapRequest beatmapLookupRequest;
+        private GetBeatmapRequest? beatmapLookupRequest;
 
         [BackgroundDependencyLoader]
         private void load()
         {
-            string stablePath = stableInfo.StablePath ?? findStablePath();
+            string? stablePath = stableInfo.StablePath ?? findStablePath();
             initialiseIPCStorage(stablePath);
         }
 
-        [CanBeNull]
+        private Storage? initialiseIPCStorage(string? path)
-        private Storage initialiseIPCStorage(string path)
         {
             scheduled?.Cancel();
 
@@ -89,7 +85,7 @@ namespace osu.Game.Tournament.IPC
 
                                     lastBeatmapId = beatmapId;
 
-                                    var existing = ladder.CurrentMatch.Value?.Round.Value?.Beatmaps.FirstOrDefault(b => b.ID == beatmapId && b.Beatmap != null);
+                                    var existing = ladder.CurrentMatch.Value?.Round.Value?.Beatmaps.FirstOrDefault(b => b.ID == beatmapId);
 
                                     if (existing != null)
                                         Beatmap.Value = existing.Beatmap;
@@ -97,6 +93,7 @@ namespace osu.Game.Tournament.IPC
                                     {
                                         beatmapLookupRequest = new GetBeatmapRequest(new APIBeatmap { OnlineID = beatmapId });
                                         beatmapLookupRequest.Success += b => Beatmap.Value = new TournamentBeatmap(b);
+                                        beatmapLookupRequest.Failure += _ => Beatmap.Value = null;
                                         API.Queue(beatmapLookupRequest);
                                     }
                                 }
@@ -114,7 +111,7 @@ namespace osu.Game.Tournament.IPC
                             using (var stream = IPCStorage.GetStream(file_ipc_channel_filename))
                             using (var sr = new StreamReader(stream))
                             {
-                                ChatChannel.Value = sr.ReadLine();
+                                ChatChannel.Value = sr.ReadLine().AsNonNull();
                             }
                         }
                         catch (Exception)
@@ -140,8 +137,8 @@ namespace osu.Game.Tournament.IPC
                             using (var stream = IPCStorage.GetStream(file_ipc_scores_filename))
                             using (var sr = new StreamReader(stream))
                             {
-                                Score1.Value = int.Parse(sr.ReadLine());
+                                Score1.Value = int.Parse(sr.ReadLine().AsNonNull());
-                                Score2.Value = int.Parse(sr.ReadLine());
+                                Score2.Value = int.Parse(sr.ReadLine().AsNonNull());
                             }
                         }
                         catch (Exception)
@@ -164,7 +161,7 @@ namespace osu.Game.Tournament.IPC
         /// </summary>
         /// <param name="path">Path to the IPC directory</param>
         /// <returns>Whether the supplied path was a valid IPC directory.</returns>
-        public bool SetIPCLocation(string path)
+        public bool SetIPCLocation(string? path)
         {
             if (path == null || !ipcFileExistsInDirectory(path))
                 return false;
@@ -184,29 +181,28 @@ namespace osu.Game.Tournament.IPC
         /// <returns>Whether an IPC directory was successfully auto-detected.</returns>
         public bool AutoDetectIPCLocation() => SetIPCLocation(findStablePath());
 
-        private static bool ipcFileExistsInDirectory(string p) => p != null && File.Exists(Path.Combine(p, "ipc.txt"));
+        private static bool ipcFileExistsInDirectory(string? p) => p != null && File.Exists(Path.Combine(p, "ipc.txt"));
 
-        [CanBeNull]
+        private string? findStablePath()
-        private string findStablePath()
         {
-            string stableInstallPath = findFromEnvVar() ??
+            string? stableInstallPath = findFromEnvVar() ??
-                                       findFromRegistry() ??
+                                        findFromRegistry() ??
-                                       findFromLocalAppData() ??
+                                        findFromLocalAppData() ??
-                                       findFromDotFolder();
+                                        findFromDotFolder();
 
             Logger.Log($"Stable path for tourney usage: {stableInstallPath}");
             return stableInstallPath;
         }
 
-        private string findFromEnvVar()
+        private string? findFromEnvVar()
         {
             try
             {
                 Logger.Log("Trying to find stable with environment variables");
-                string stableInstallPath = Environment.GetEnvironmentVariable("OSU_STABLE_PATH");
+                string? stableInstallPath = Environment.GetEnvironmentVariable("OSU_STABLE_PATH");
 
                 if (ipcFileExistsInDirectory(stableInstallPath))
-                    return stableInstallPath;
+                    return stableInstallPath!;
             }
             catch
             {
@@ -215,7 +211,7 @@ namespace osu.Game.Tournament.IPC
             return null;
         }
 
-        private string findFromLocalAppData()
+        private string? findFromLocalAppData()
         {
             Logger.Log("Trying to find stable in %LOCALAPPDATA%");
             string stableInstallPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), @"osu!");
@@ -226,7 +222,7 @@ namespace osu.Game.Tournament.IPC
             return null;
         }
 
-        private string findFromDotFolder()
+        private string? findFromDotFolder()
         {
             Logger.Log("Trying to find stable in dotfolders");
             string stableInstallPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".osu");
@@ -237,16 +233,16 @@ namespace osu.Game.Tournament.IPC
             return null;
         }
 
-        private string findFromRegistry()
+        private string? findFromRegistry()
         {
             Logger.Log("Trying to find stable in registry");
 
             try
             {
-                string stableInstallPath;
+                string? stableInstallPath;
 
 #pragma warning disable CA1416
-                using (RegistryKey key = Registry.ClassesRoot.OpenSubKey("osu"))
+                using (RegistryKey? key = Registry.ClassesRoot.OpenSubKey("osu"))
                     stableInstallPath = key?.OpenSubKey(@"shell\open\command")?.GetValue(string.Empty)?.ToString()?.Split('"')[1].Replace("osu!.exe", "");
 #pragma warning restore CA1416
 

osu.Game.Tournament/IPC/MatchIPCInfo.cs

@@ -10,7 +10,7 @@ namespace osu.Game.Tournament.IPC
 {
     public partial class MatchIPCInfo : Component
     {
-        public Bindable<TournamentBeatmap> Beatmap { get; } = new Bindable<TournamentBeatmap>();
+        public Bindable<TournamentBeatmap?> Beatmap { get; } = new Bindable<TournamentBeatmap?>();
         public Bindable<LegacyMods> Mods { get; } = new Bindable<LegacyMods>();
         public Bindable<TourneyState> State { get; } = new Bindable<TourneyState>();
         public Bindable<string> ChatChannel { get; } = new Bindable<string>();

osu.Game.Tournament/JsonPointConverter.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Diagnostics;
 using System.Drawing;
@@ -28,7 +26,7 @@ namespace osu.Game.Tournament
             if (reader.TokenType != JsonToken.StartObject)
             {
                 // if there's no object present then this is using string representation (System.Drawing.Point serializes to "x,y")
-                string str = (string)reader.Value;
+                string? str = (string?)reader.Value;
 
                 Debug.Assert(str != null);
 
@@ -45,9 +43,12 @@ namespace osu.Game.Tournament
 
                 if (reader.TokenType == JsonToken.PropertyName)
                 {
-                    string name = reader.Value?.ToString();
+                    string? name = reader.Value?.ToString();
                     int? val = reader.ReadAsInt32();
 
+                    if (name == null)
+                        continue;
+
                     if (val == null)
                         continue;
 

osu.Game.Tournament/Models/LadderInfo.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using Newtonsoft.Json;
@@ -17,7 +15,7 @@ namespace osu.Game.Tournament.Models
     [Serializable]
     public class LadderInfo
     {
-        public Bindable<RulesetInfo> Ruleset = new Bindable<RulesetInfo>();
+        public Bindable<RulesetInfo?> Ruleset = new Bindable<RulesetInfo?>();
 
         public BindableList<TournamentMatch> Matches = new BindableList<TournamentMatch>();
         public BindableList<TournamentRound> Rounds = new BindableList<TournamentRound>();
@@ -27,7 +25,7 @@ namespace osu.Game.Tournament.Models
         public List<TournamentProgression> Progressions = new List<TournamentProgression>();
 
         [JsonIgnore] // updated manually in TournamentGameBase
-        public Bindable<TournamentMatch> CurrentMatch = new Bindable<TournamentMatch>();
+        public Bindable<TournamentMatch?> CurrentMatch = new Bindable<TournamentMatch?>();
 
         public Bindable<int> ChromaKeyWidth = new BindableInt(1024)
         {

osu.Game.Tournament/Models/RoundBeatmap.cs

@@ -8,7 +8,6 @@ namespace osu.Game.Tournament.Models
     public class RoundBeatmap
     {
         public int ID;
-
         public string Mods = string.Empty;
 
         [JsonProperty("BeatmapInfo")]

osu.Game.Tournament/Models/StableInfo.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.IO;
 using Newtonsoft.Json;
@@ -20,12 +18,12 @@ namespace osu.Game.Tournament.Models
         /// <summary>
         /// Path to the IPC directory used by the stable (cutting-edge) install.
         /// </summary>
-        public string StablePath { get; set; }
+        public string? StablePath { get; set; }
 
         /// <summary>
         /// Fired whenever stable info is successfully saved to file.
         /// </summary>
-        public event Action OnStableInfoSaved;
+        public event Action? OnStableInfoSaved;
 
         private const string config_path = "stable.json";
 

osu.Game.Tournament/Models/TournamentMatch.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
@@ -33,16 +31,16 @@ namespace osu.Game.Tournament.Models
         }
 
         [JsonIgnore]
-        public readonly Bindable<TournamentTeam> Team1 = new Bindable<TournamentTeam>();
+        public readonly Bindable<TournamentTeam?> Team1 = new Bindable<TournamentTeam?>();
 
-        public string Team1Acronym;
+        public string? Team1Acronym;
 
         public readonly Bindable<int?> Team1Score = new Bindable<int?>();
 
         [JsonIgnore]
-        public readonly Bindable<TournamentTeam> Team2 = new Bindable<TournamentTeam>();
+        public readonly Bindable<TournamentTeam?> Team2 = new Bindable<TournamentTeam?>();
 
-        public string Team2Acronym;
+        public string? Team2Acronym;
 
         public readonly Bindable<int?> Team2Score = new Bindable<int?>();
 
@@ -53,13 +51,13 @@ namespace osu.Game.Tournament.Models
         public readonly ObservableCollection<BeatmapChoice> PicksBans = new ObservableCollection<BeatmapChoice>();
 
         [JsonIgnore]
-        public readonly Bindable<TournamentRound> Round = new Bindable<TournamentRound>();
+        public readonly Bindable<TournamentRound?> Round = new Bindable<TournamentRound?>();
 
         [JsonIgnore]
-        public readonly Bindable<TournamentMatch> Progression = new Bindable<TournamentMatch>();
+        public readonly Bindable<TournamentMatch?> Progression = new Bindable<TournamentMatch?>();
 
         [JsonIgnore]
-        public readonly Bindable<TournamentMatch> LosersProgression = new Bindable<TournamentMatch>();
+        public readonly Bindable<TournamentMatch?> LosersProgression = new Bindable<TournamentMatch?>();
 
         /// <summary>
         /// Should not be set directly. Use LadderInfo.CurrentMatch.Value = this instead.
@@ -79,7 +77,7 @@ namespace osu.Game.Tournament.Models
             Team2.BindValueChanged(t => Team2Acronym = t.NewValue?.Acronym.Value, true);
         }
 
-        public TournamentMatch(TournamentTeam team1 = null, TournamentTeam team2 = null)
+        public TournamentMatch(TournamentTeam? team1 = null, TournamentTeam? team2 = null)
             : this()
         {
             Team1.Value = team1;
@@ -87,10 +85,10 @@ namespace osu.Game.Tournament.Models
         }
 
         [JsonIgnore]
-        public TournamentTeam Winner => !Completed.Value ? null : Team1Score.Value > Team2Score.Value ? Team1.Value : Team2.Value;
+        public TournamentTeam? Winner => !Completed.Value ? null : Team1Score.Value > Team2Score.Value ? Team1.Value : Team2.Value;
 
         [JsonIgnore]
-        public TournamentTeam Loser => !Completed.Value ? null : Team1Score.Value > Team2Score.Value ? Team2.Value : Team1.Value;
+        public TournamentTeam? Loser => !Completed.Value ? null : Team1Score.Value > Team2Score.Value ? Team2.Value : Team1.Value;
 
         public TeamColour WinnerColour => Winner == Team1.Value ? TeamColour.Red : TeamColour.Blue;
 

osu.Game.Tournament/Models/TournamentTeam.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using Newtonsoft.Json;
@@ -39,7 +37,7 @@ namespace osu.Game.Tournament.Models
             {
                 int[] ranks = Players.Select(p => p.Rank)
                                      .Where(i => i.HasValue)
-                                     .Select(i => i.Value)
+                                     .Select(i => i!.Value)
                                      .ToArray();
 
                 if (ranks.Length == 0)
@@ -66,14 +64,14 @@ namespace osu.Game.Tournament.Models
             {
                 // use a sane default flag name based on acronym.
                 if (val.OldValue.StartsWith(FlagName.Value, StringComparison.InvariantCultureIgnoreCase))
-                    FlagName.Value = val.NewValue.Length >= 2 ? val.NewValue?.Substring(0, 2).ToUpperInvariant() : string.Empty;
+                    FlagName.Value = val.NewValue?.Length >= 2 ? val.NewValue.Substring(0, 2).ToUpperInvariant() : string.Empty;
             };
 
             FullName.ValueChanged += val =>
             {
                 // use a sane acronym based on full name.
                 if (val.OldValue.StartsWith(Acronym.Value, StringComparison.InvariantCultureIgnoreCase))
-                    Acronym.Value = val.NewValue.Length >= 3 ? val.NewValue?.Substring(0, 3).ToUpperInvariant() : string.Empty;
+                    Acronym.Value = val.NewValue?.Length >= 3 ? val.NewValue.Substring(0, 3).ToUpperInvariant() : string.Empty;
             };
         }
 

osu.Game.Tournament/Screens/BeatmapInfoScreen.cs

@@ -37,7 +37,7 @@ namespace osu.Game.Tournament.Screens
             SongBar.Mods = mods.NewValue;
         }
 
-        private void beatmapChanged(ValueChangedEvent<TournamentBeatmap> beatmap)
+        private void beatmapChanged(ValueChangedEvent<TournamentBeatmap?> beatmap)
         {
             SongBar.FadeInFromZero(300, Easing.OutQuint);
             SongBar.Beatmap = beatmap.NewValue;

osu.Game.Tournament/Screens/Drawings/Components/Group.cs

@@ -84,7 +84,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
 
         public bool ContainsTeam(string fullName)
         {
-            return allTeams.Any(t => t.Team.FullName.Value == fullName);
+            return allTeams.Any(t => t.Team?.FullName.Value == fullName);
         }
 
         public bool RemoveTeam(TournamentTeam team)
@@ -112,7 +112,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
         {
             StringBuilder sb = new StringBuilder();
             foreach (GroupTeam gt in allTeams)
-                sb.AppendLine(gt.Team.FullName.Value);
+                sb.AppendLine(gt.Team?.FullName.Value);
             return sb.ToString();
         }
     }

osu.Game.Tournament/Screens/Drawings/Components/ScrollingTeamContainer.cs

@@ -1,12 +1,11 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Colour;
 using osu.Framework.Graphics.Containers;
@@ -22,8 +21,8 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
 {
     public partial class ScrollingTeamContainer : Container
     {
-        public event Action OnScrollStarted;
+        public event Action? OnScrollStarted;
-        public event Action<TournamentTeam> OnSelected;
+        public event Action<TournamentTeam>? OnSelected;
 
         private readonly List<TournamentTeam> availableTeams = new List<TournamentTeam>();
 
@@ -42,7 +41,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
 
         private double lastTime;
 
-        private ScheduledDelegate delayedStateChangeDelegate;
+        private ScheduledDelegate? delayedStateChangeDelegate;
 
         public ScrollingTeamContainer()
         {
@@ -117,7 +116,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
                     if (!Children.Any())
                         break;
 
-                    ScrollingTeam closest = null;
+                    ScrollingTeam? closest = null;
 
                     foreach (var c in Children)
                     {
@@ -137,9 +136,8 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
                             closest = stc;
                     }
 
-                    Trace.Assert(closest != null, "closest != null");
+                    Debug.Assert(closest != null, "closest != null");
 
-                    // ReSharper disable once PossibleNullReferenceException
                     offset += DrawWidth / 2f - (closest.Position.X + closest.DrawWidth / 2f);
 
                     ScrollingTeam st = closest;
@@ -147,7 +145,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
                     availableTeams.RemoveAll(at => at == st.Team);
 
                     st.Selected = true;
-                    OnSelected?.Invoke(st.Team);
+                    OnSelected?.Invoke(st.Team.AsNonNull());
 
                     delayedStateChangeDelegate = Scheduler.AddDelayed(() => setScrollState(ScrollState.Idle), 10000);
                     break;
@@ -174,7 +172,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
             setScrollState(ScrollState.Idle);
         }
 
-        public void AddTeams(IEnumerable<TournamentTeam> teams)
+        public void AddTeams(IEnumerable<TournamentTeam>? teams)
         {
             if (teams == null)
                 return;
@@ -311,6 +309,8 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
 
         public partial class ScrollingTeam : DrawableTournamentTeam
         {
+            public new TournamentTeam Team => base.Team.AsNonNull();
+
             public const float WIDTH = 58;
             public const float HEIGHT = 44;
 

osu.Game.Tournament/Screens/Drawings/Components/StorageBackedTeamList.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -39,7 +37,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
                     {
                         while (sr.Peek() != -1)
                         {
-                            string line = sr.ReadLine()?.Trim();
+                            string? line = sr.ReadLine()?.Trim();
 
                             if (string.IsNullOrEmpty(line))
                                 continue;
@@ -56,7 +54,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
                             teams.Add(new TournamentTeam
                             {
                                 FullName = { Value = split[1], },
-                                Acronym = { Value = split.Length >= 3 ? split[2] : null, },
+                                Acronym = { Value = split.Length >= 3 ? split[2] : string.Empty, },
                                 FlagName = { Value = split[0] }
                             });
                         }

osu.Game.Tournament/Screens/Drawings/Components/VisualiserContainer.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Allocation;
@@ -72,7 +70,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
 
             private float leftPos => -(float)((Time.Current + Offset) / CycleTime) + expiredCount;
 
-            private Texture texture;
+            private Texture texture = null!;
 
             private int expiredCount;
 

osu.Game.Tournament/Screens/Drawings/DrawingsScreen.cs

@@ -1,14 +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.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using osu.Framework.Allocation;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
@@ -28,28 +27,29 @@ namespace osu.Game.Tournament.Screens.Drawings
     {
         private const string results_filename = "drawings_results.txt";
 
-        private ScrollingTeamContainer teamsContainer;
+        private ScrollingTeamContainer teamsContainer = null!;
-        private GroupContainer groupsContainer;
+        private GroupContainer groupsContainer = null!;
-        private TournamentSpriteText fullTeamNameText;
+        private TournamentSpriteText fullTeamNameText = null!;
 
         private readonly List<TournamentTeam> allTeams = new List<TournamentTeam>();
 
-        private DrawingsConfigManager drawingsConfig;
+        private DrawingsConfigManager drawingsConfig = null!;
 
-        private Task writeOp;
+        private Task? writeOp;
 
-        private Storage storage;
+        private Storage storage = null!;
 
-        public ITeamList TeamList;
+        public ITeamList TeamList = null!;
 
         [BackgroundDependencyLoader]
         private void load(Storage storage)
         {
-            RelativeSizeAxes = Axes.Both;
-
             this.storage = storage;
 
-            TeamList ??= new StorageBackedTeamList(storage);
+            RelativeSizeAxes = Axes.Both;
+
+            if (TeamList.IsNull())
+                TeamList = new StorageBackedTeamList(storage);
 
             if (!TeamList.Teams.Any())
             {
@@ -251,7 +251,7 @@ namespace osu.Game.Tournament.Screens.Drawings
                     using (Stream stream = storage.GetStream(results_filename, FileAccess.Read, FileMode.Open))
                     using (StreamReader sr = new StreamReader(stream))
                     {
-                        string line;
+                        string? line;
 
                         while ((line = sr.ReadLine()?.Trim()) != null)
                         {
@@ -261,8 +261,7 @@ namespace osu.Game.Tournament.Screens.Drawings
                             if (line.ToUpperInvariant().StartsWith("GROUP", StringComparison.Ordinal))
                                 continue;
 
-                            // ReSharper disable once AccessToModifiedClosure
+                            TournamentTeam? teamToAdd = allTeams.FirstOrDefault(t => t.FullName.Value == line);
-                            TournamentTeam teamToAdd = allTeams.FirstOrDefault(t => t.FullName.Value == line);
 
                             if (teamToAdd == null)
                                 continue;

osu.Game.Tournament/Screens/Editors/LadderEditorScreen.cs

@@ -1,12 +1,9 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Drawing;
 using System.Linq;
-using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -35,13 +32,12 @@ namespace osu.Game.Tournament.Screens.Editors
         [Cached]
         private LadderEditorInfo editorInfo = new LadderEditorInfo();
 
-        private WarningBox rightClickMessage;
+        private WarningBox rightClickMessage = null!;
 
-        private RectangularPositionSnapGrid grid;
+        private RectangularPositionSnapGrid grid = null!;
 
-        [Resolved(canBeNull: true)]
+        [Resolved]
-        [CanBeNull]
+        private IDialogOverlay? dialogOverlay { get; set; }
-        private IDialogOverlay dialogOverlay { get; set; }
 
         protected override bool DrawLoserPaths => true;
 
@@ -94,36 +90,28 @@ namespace osu.Game.Tournament.Screens.Editors
             ScrollContent.Add(new JoinVisualiser(MatchesContainer, match, losers, UpdateLayout));
         }
 
-        public MenuItem[] ContextMenuItems
+        public MenuItem[] ContextMenuItems =>
-        {
+            new MenuItem[]
-            get
             {
-                if (editorInfo == null)
+                new OsuMenuItem("Create new match", MenuItemType.Highlighted, () =>
-                    return Array.Empty<MenuItem>();
-
-                return new MenuItem[]
                 {
-                    new OsuMenuItem("Create new match", MenuItemType.Highlighted, () =>
+                    Vector2 pos = MatchesContainer.Count == 0 ? Vector2.Zero : lastMatchesContainerMouseDownPosition;
+
+                    TournamentMatch newMatch = new TournamentMatch { Position = { Value = new Point((int)pos.X, (int)pos.Y) } };
+
+                    LadderInfo.Matches.Add(newMatch);
+
+                    editorInfo.Selected.Value = newMatch;
+                }),
+                new OsuMenuItem("Reset teams", MenuItemType.Destructive, () =>
+                {
+                    dialogOverlay?.Push(new LadderResetTeamsDialog(() =>
                     {
-                        Vector2 pos = MatchesContainer.Count == 0 ? Vector2.Zero : lastMatchesContainerMouseDownPosition;
+                        foreach (var p in MatchesContainer)
-
+                            p.Match.Reset();
-                        TournamentMatch newMatch = new TournamentMatch { Position = { Value = new Point((int)pos.X, (int)pos.Y) } };
+                    }));
-
+                })
-                        LadderInfo.Matches.Add(newMatch);
+            };
-
-                        editorInfo.Selected.Value = newMatch;
-                    }),
-                    new OsuMenuItem("Reset teams", MenuItemType.Destructive, () =>
-                    {
-                        dialogOverlay?.Push(new LadderResetTeamsDialog(() =>
-                        {
-                            foreach (var p in MatchesContainer)
-                                p.Match.Reset();
-                        }));
-                    })
-                };
-            }
-        }
 
         public void Remove(TournamentMatch match)
         {
@@ -135,11 +123,11 @@ namespace osu.Game.Tournament.Screens.Editors
             private readonly Container<DrawableTournamentMatch> matchesContainer;
             public readonly TournamentMatch Source;
             private readonly bool losers;
-            private readonly Action complete;
+            private readonly Action? complete;
 
-            private ProgressionPath path;
+            private ProgressionPath? path;
 
-            public JoinVisualiser(Container<DrawableTournamentMatch> matchesContainer, TournamentMatch source, bool losers, Action complete)
+            public JoinVisualiser(Container<DrawableTournamentMatch> matchesContainer, TournamentMatch source, bool losers, Action? complete)
             {
                 this.matchesContainer = matchesContainer;
                 RelativeSizeAxes = Axes.Both;
@@ -153,7 +141,7 @@ namespace osu.Game.Tournament.Screens.Editors
                     Source.Progression.Value = null;
             }
 
-            private DrawableTournamentMatch findTarget(InputState state)
+            private DrawableTournamentMatch? findTarget(InputState state)
             {
                 return matchesContainer.FirstOrDefault(d => d.ReceivePositionalInputAt(state.Mouse.Position));
             }

osu.Game.Tournament/Screens/Gameplay/Components/MatchHeader.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -14,9 +12,9 @@ namespace osu.Game.Tournament.Screens.Gameplay.Components
 {
     public partial class MatchHeader : Container
     {
-        private TeamScoreDisplay teamDisplay1;
+        private TeamScoreDisplay teamDisplay1 = null!;
-        private TeamScoreDisplay teamDisplay2;
+        private TeamScoreDisplay teamDisplay2 = null!;
-        private DrawableTournamentHeaderLogo logo;
+        private DrawableTournamentHeaderLogo logo = null!;
 
         private bool showScores = true;
 

osu.Game.Tournament/Screens/Gameplay/Components/TeamDisplay.cs

@@ -35,7 +35,7 @@ namespace osu.Game.Tournament.Screens.Gameplay.Components
             }
         }
 
-        public TeamDisplay(TournamentTeam team, TeamColour colour, Bindable<int?> currentTeamScore, int pointsToWin)
+        public TeamDisplay(TournamentTeam? team, TeamColour colour, Bindable<int?> currentTeamScore, int pointsToWin)
             : base(team)
         {
             AutoSizeAxes = Axes.Both;

osu.Game.Tournament/Screens/Gameplay/Components/TeamScoreDisplay.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -17,16 +15,22 @@ namespace osu.Game.Tournament.Screens.Gameplay.Components
     {
         private readonly TeamColour teamColour;
 
-        private readonly Bindable<TournamentMatch> currentMatch = new Bindable<TournamentMatch>();
+        private readonly Bindable<TournamentMatch?> currentMatch = new Bindable<TournamentMatch?>();
-        private readonly Bindable<TournamentTeam> currentTeam = new Bindable<TournamentTeam>();
+        private readonly Bindable<TournamentTeam?> currentTeam = new Bindable<TournamentTeam?>();
         private readonly Bindable<int?> currentTeamScore = new Bindable<int?>();
 
-        private TeamDisplay teamDisplay;
+        private TeamDisplay? teamDisplay;
 
         public bool ShowScore
         {
-            get => teamDisplay.ShowScore;
+            get => teamDisplay?.ShowScore ?? false;
-            set => teamDisplay.ShowScore = value;
+            set
+            {
+                if (teamDisplay != null)
+                {
+                    teamDisplay.ShowScore = value;
+                }
+            }
         }
 
         public TeamScoreDisplay(TeamColour teamColour)
@@ -48,7 +52,7 @@ namespace osu.Game.Tournament.Screens.Gameplay.Components
             updateMatch();
         }
 
-        private void matchChanged(ValueChangedEvent<TournamentMatch> match)
+        private void matchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             currentTeamScore.UnbindBindings();
             currentTeam.UnbindBindings();
@@ -78,7 +82,7 @@ namespace osu.Game.Tournament.Screens.Gameplay.Components
             switch (e.Button)
             {
                 case MouseButton.Left:
-                    if (currentTeamScore.Value < currentMatch.Value.PointsToWin)
+                    if (currentTeamScore.Value < currentMatch.Value?.PointsToWin)
                         currentTeamScore.Value++;
                     return true;
 
@@ -91,7 +95,7 @@ namespace osu.Game.Tournament.Screens.Gameplay.Components
             return base.OnMouseDown(e);
         }
 
-        private void teamChanged(ValueChangedEvent<TournamentTeam> team)
+        private void teamChanged(ValueChangedEvent<TournamentTeam?> team)
         {
             bool wasShowingScores = teamDisplay?.ShowScore ?? false;
 

osu.Game.Tournament/Screens/Gameplay/Components/TournamentMatchScoreDisplay.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -146,7 +144,7 @@ namespace osu.Game.Tournament.Screens.Gameplay.Components
 
         private partial class MatchScoreCounter : CommaSeparatedScoreCounter
         {
-            private OsuSpriteText displayedSpriteText;
+            private OsuSpriteText displayedSpriteText = null!;
 
             public MatchScoreCounter()
             {

osu.Game.Tournament/Screens/Gameplay/GameplayScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -26,16 +24,16 @@ namespace osu.Game.Tournament.Screens.Gameplay
         private readonly BindableBool warmup = new BindableBool();
 
         public readonly Bindable<TourneyState> State = new Bindable<TourneyState>();
-        private OsuButton warmupButton;
+        private OsuButton warmupButton = null!;
-        private MatchIPCInfo ipc;
+        private MatchIPCInfo ipc = null!;
-
-        [Resolved(canBeNull: true)]
-        private TournamentSceneManager sceneManager { get; set; }
 
         [Resolved]
-        private TournamentMatchChatDisplay chat { get; set; }
+        private TournamentSceneManager? sceneManager { get; set; }
 
-        private Drawable chroma;
+        [Resolved]
+        private TournamentMatchChatDisplay chat { get; set; } = null!;
+
+        private Drawable chroma = null!;
 
         [BackgroundDependencyLoader]
         private void load(LadderInfo ladder, MatchIPCInfo ipc)
@@ -142,7 +140,7 @@ namespace osu.Game.Tournament.Screens.Gameplay
             State.BindValueChanged(_ => updateState(), true);
         }
 
-        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch> match)
+        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             base.CurrentMatchChanged(match);
 
@@ -153,29 +151,35 @@ namespace osu.Game.Tournament.Screens.Gameplay
             scheduledScreenChange?.Cancel();
         }
 
-        private ScheduledDelegate scheduledScreenChange;
+        private ScheduledDelegate? scheduledScreenChange;
-        private ScheduledDelegate scheduledContract;
+        private ScheduledDelegate? scheduledContract;
 
-        private TournamentMatchScoreDisplay scoreDisplay;
+        private TournamentMatchScoreDisplay scoreDisplay = null!;
 
         private TourneyState lastState;
-        private MatchHeader header;
+        private MatchHeader header = null!;
 
         private void contract()
         {
+            if (!IsLoaded)
+                return;
+
             scheduledContract?.Cancel();
 
             SongBar.Expanded = false;
             scoreDisplay.FadeOut(100);
-            using (chat?.BeginDelayedSequence(500))
+            using (chat.BeginDelayedSequence(500))
-                chat?.Expand();
+                chat.Expand();
         }
 
         private void expand()
         {
+            if (!IsLoaded)
+                return;
+
             scheduledContract?.Cancel();
 
-            chat?.Contract();
+            chat.Contract();
 
             using (BeginDelayedSequence(300))
             {
@@ -252,7 +256,7 @@ namespace osu.Game.Tournament.Screens.Gameplay
         private partial class ChromaArea : CompositeDrawable
         {
             [Resolved]
-            private LadderInfo ladder { get; set; }
+            private LadderInfo ladder { get; set; } = null!;
 
             [BackgroundDependencyLoader]
             private void load()

osu.Game.Tournament/Screens/Ladder/Components/DrawableMatchTeam.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -28,20 +26,20 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
     {
         private readonly TournamentMatch match;
         private readonly bool losers;
-        private TournamentSpriteText scoreText;
+        private TournamentSpriteText scoreText = null!;
-        private Box background;
+        private Box background = null!;
-        private Box backgroundRight;
+        private Box backgroundRight = null!;
 
         private readonly Bindable<int?> score = new Bindable<int?>();
         private readonly BindableBool completed = new BindableBool();
 
         private Color4 colourWinner;
 
-        private readonly Func<bool> isWinner;
+        private readonly Func<bool>? isWinner;
-        private LadderEditorScreen ladderEditor;
+        private LadderEditorScreen ladderEditor = null!;
 
-        [Resolved(canBeNull: true)]
+        [Resolved]
-        private LadderInfo ladderInfo { get; set; }
+        private LadderInfo? ladderInfo { get; set; }
 
         private void setCurrent()
         {
@@ -55,10 +53,10 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
             ladderInfo.CurrentMatch.Value.Current.Value = true;
         }
 
-        [Resolved(CanBeNull = true)]
+        [Resolved]
-        private LadderEditorInfo editorInfo { get; set; }
+        private LadderEditorInfo? editorInfo { get; set; }
 
-        public DrawableMatchTeam(TournamentTeam team, TournamentMatch match, bool losers)
+        public DrawableMatchTeam(TournamentTeam? team, TournamentMatch match, bool losers)
             : base(team)
         {
             this.match = match;
@@ -72,14 +70,11 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
             AcronymText.Padding = new MarginPadding { Left = 50 };
             AcronymText.Font = OsuFont.Torus.With(size: 22, weight: FontWeight.Bold);
 
-            if (match != null)
+            isWinner = () => match.Winner == Team;
-            {
-                isWinner = () => match.Winner == Team;
 
-                completed.BindTo(match.Completed);
+            completed.BindTo(match.Completed);
-                if (team != null)
+            if (team != null)
-                    score.BindTo(team == match.Team1.Value ? match.Team1Score : match.Team2Score);
+                score.BindTo(team == match.Team1.Value ? match.Team1Score : match.Team2Score);
-            }
         }
 
         [BackgroundDependencyLoader(true)]

osu.Game.Tournament/Screens/Ladder/Components/DrawableTournamentMatch.cs

@@ -1,10 +1,9 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Drawing;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -27,13 +26,13 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
         protected readonly FillFlowContainer<DrawableMatchTeam> Flow;
         private readonly Drawable selectionBox;
         private readonly Drawable currentMatchSelectionBox;
-        private Bindable<TournamentMatch> globalSelection;
+        private Bindable<TournamentMatch>? globalSelection;
 
-        [Resolved(CanBeNull = true)]
+        [Resolved]
-        private LadderEditorInfo editorInfo { get; set; }
+        private LadderEditorInfo? editorInfo { get; set; }
 
-        [Resolved(CanBeNull = true)]
+        [Resolved]
-        private LadderInfo ladderInfo { get; set; }
+        private LadderInfo? ladderInfo { get; set; }
 
         public DrawableTournamentMatch(TournamentMatch match, bool editor = false)
         {
@@ -129,7 +128,7 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
         /// <summary>
         /// Fired when something changed that requires a ladder redraw.
         /// </summary>
-        public Action Changed;
+        public Action? Changed;
 
         private readonly List<IUnbindable> refBindables = new List<IUnbindable>();
 
@@ -201,20 +200,22 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
             }
             else
             {
-                transferProgression(Match.Progression?.Value, Match.Winner);
+                Debug.Assert(Match.Winner != null);
-                transferProgression(Match.LosersProgression?.Value, Match.Loser);
+                transferProgression(Match.Progression.Value, Match.Winner);
+                Debug.Assert(Match.Loser != null);
+                transferProgression(Match.LosersProgression.Value, Match.Loser);
             }
 
             Changed?.Invoke();
         }
 
-        private void transferProgression(TournamentMatch destination, TournamentTeam team)
+        private void transferProgression(TournamentMatch? destination, TournamentTeam team)
         {
             if (destination == null) return;
 
             bool progressionAbove = destination.ID < Match.ID;
 
-            Bindable<TournamentTeam> destinationTeam;
+            Bindable<TournamentTeam?> destinationTeam;
 
             // check for the case where we have already transferred out value
             if (destination.Team1.Value == team)
@@ -268,8 +269,8 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
             {
                 foreach (var conditional in Match.ConditionalMatches)
                 {
-                    bool team1Match = conditional.Acronyms.Contains(Match.Team1Acronym);
+                    bool team1Match = Match.Team1Acronym != null && conditional.Acronyms.Contains(Match.Team1Acronym);
-                    bool team2Match = conditional.Acronyms.Contains(Match.Team2Acronym);
+                    bool team2Match = Match.Team2Acronym != null && conditional.Acronyms.Contains(Match.Team2Acronym);
 
                     if (team1Match && team2Match)
                         Match.Date.Value = conditional.Date.Value;
@@ -344,6 +345,9 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
             Match.Progression.Value = null;
             Match.LosersProgression.Value = null;
 
+            if (ladderInfo == null)
+                return;
+
             ladderInfo.Matches.Remove(Match);
 
             foreach (var m in ladderInfo.Matches)

osu.Game.Tournament/Screens/Ladder/Components/DrawableTournamentRound.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using JetBrains.Annotations;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -52,7 +50,7 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
             name.BindValueChanged(_ => textName.Text = ((losers ? "Losers " : "") + round.Name).ToUpperInvariant(), true);
 
             description = round.Description.GetBoundCopy();
-            description.BindValueChanged(_ => textDescription.Text = round.Description.Value?.ToUpperInvariant(), true);
+            description.BindValueChanged(_ => textDescription.Text = round.Description.Value?.ToUpperInvariant() ?? string.Empty, true);
         }
     }
 }

osu.Game.Tournament/Screens/Ladder/Components/LadderEditorSettings.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Diagnostics;
@@ -23,17 +21,17 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
 {
     public partial class LadderEditorSettings : CompositeDrawable
     {
-        private SettingsDropdown<TournamentRound> roundDropdown;
+        private SettingsDropdown<TournamentRound?> roundDropdown = null!;
-        private PlayerCheckbox losersCheckbox;
+        private PlayerCheckbox losersCheckbox = null!;
-        private DateTextBox dateTimeBox;
+        private DateTextBox dateTimeBox = null!;
-        private SettingsTeamDropdown team1Dropdown;
+        private SettingsTeamDropdown team1Dropdown = null!;
-        private SettingsTeamDropdown team2Dropdown;
+        private SettingsTeamDropdown team2Dropdown = null!;
 
         [Resolved]
-        private LadderEditorInfo editorInfo { get; set; }
+        private LadderEditorInfo editorInfo { get; set; } = null!;
 
         [Resolved]
-        private LadderInfo ladderInfo { get; set; }
+        private LadderInfo ladderInfo { get; set; } = null!;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -77,7 +75,7 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
             };
         }
 
-        private void roundDropdownChanged(ValueChangedEvent<TournamentRound> round)
+        private void roundDropdownChanged(ValueChangedEvent<TournamentRound?> round)
         {
             if (editorInfo.Selected.Value?.Date.Value < round.NewValue?.StartDate.Value)
             {
@@ -101,11 +99,11 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
         {
         }
 
-        private partial class SettingsRoundDropdown : SettingsDropdown<TournamentRound>
+        private partial class SettingsRoundDropdown : SettingsDropdown<TournamentRound?>
         {
             public SettingsRoundDropdown(BindableList<TournamentRound> rounds)
             {
-                Current = new Bindable<TournamentRound>();
+                Current = new Bindable<TournamentRound?>();
 
                 foreach (var r in rounds.Prepend(new TournamentRound()))
                     add(r);

osu.Game.Tournament/Screens/Ladder/Components/SettingsTeamDropdown.cs

@@ -12,7 +12,7 @@ using osu.Game.Tournament.Models;
 
 namespace osu.Game.Tournament.Screens.Ladder.Components
 {
-    public partial class SettingsTeamDropdown : SettingsDropdown<TournamentTeam>
+    public partial class SettingsTeamDropdown : SettingsDropdown<TournamentTeam?>
     {
         public SettingsTeamDropdown(BindableList<TournamentTeam> teams)
         {

osu.Game.Tournament/Screens/Ladder/LadderScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Collections.Specialized;
 using System.Diagnostics;
 using System.Linq;
@@ -22,13 +20,13 @@ namespace osu.Game.Tournament.Screens.Ladder
 {
     public partial class LadderScreen : TournamentScreen
     {
-        protected Container<DrawableTournamentMatch> MatchesContainer;
+        protected Container<DrawableTournamentMatch> MatchesContainer = null!;
-        private Container<Path> paths;
+        private Container<Path> paths = null!;
-        private Container headings;
+        private Container headings = null!;
 
-        protected LadderDragContainer ScrollContent;
+        protected LadderDragContainer ScrollContent = null!;
 
-        protected Container Content;
+        protected Container Content = null!;
 
         [BackgroundDependencyLoader]
         private void load()

osu.Game.Tournament/Screens/MapPool/MapPoolScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -24,20 +22,20 @@ namespace osu.Game.Tournament.Screens.MapPool
 {
     public partial class MapPoolScreen : TournamentMatchScreen
     {
-        private FillFlowContainer<FillFlowContainer<TournamentBeatmapPanel>> mapFlows;
+        private FillFlowContainer<FillFlowContainer<TournamentBeatmapPanel>> mapFlows = null!;
 
-        [Resolved(canBeNull: true)]
+        [Resolved]
-        private TournamentSceneManager sceneManager { get; set; }
+        private TournamentSceneManager? sceneManager { get; set; }
 
         private TeamColour pickColour;
         private ChoiceType pickType;
 
-        private OsuButton buttonRedBan;
+        private OsuButton buttonRedBan = null!;
-        private OsuButton buttonBlueBan;
+        private OsuButton buttonBlueBan = null!;
-        private OsuButton buttonRedPick;
+        private OsuButton buttonRedPick = null!;
-        private OsuButton buttonBluePick;
+        private OsuButton buttonBluePick = null!;
 
-        private ScheduledDelegate scheduledScreenChange;
+        private ScheduledDelegate? scheduledScreenChange;
 
         [BackgroundDependencyLoader]
         private void load(MatchIPCInfo ipc)
@@ -113,7 +111,7 @@ namespace osu.Game.Tournament.Screens.MapPool
             ipc.Beatmap.BindValueChanged(beatmapChanged);
         }
 
-        private Bindable<bool> splitMapPoolByMods;
+        private Bindable<bool>? splitMapPoolByMods;
 
         protected override void LoadComplete()
         {
@@ -123,13 +121,13 @@ namespace osu.Game.Tournament.Screens.MapPool
             splitMapPoolByMods.BindValueChanged(_ => updateDisplay());
         }
 
-        private void beatmapChanged(ValueChangedEvent<TournamentBeatmap> beatmap)
+        private void beatmapChanged(ValueChangedEvent<TournamentBeatmap?> beatmap)
         {
             if (CurrentMatch.Value == null || CurrentMatch.Value.PicksBans.Count(p => p.Type == ChoiceType.Ban) < 2)
                 return;
 
             // if bans have already been placed, beatmap changes result in a selection being made autoamtically
-            if (beatmap.NewValue.OnlineID > 0)
+            if (beatmap.NewValue?.OnlineID > 0)
                 addForBeatmap(beatmap.NewValue.OnlineID);
         }
 
@@ -148,6 +146,9 @@ namespace osu.Game.Tournament.Screens.MapPool
 
         private void setNextMode()
         {
+            if (CurrentMatch.Value == null)
+                return;
+
             const TeamColour roll_winner = TeamColour.Red; //todo: draw from match
 
             var nextColour = (CurrentMatch.Value.PicksBans.LastOrDefault()?.Team ?? roll_winner) == TeamColour.Red ? TeamColour.Blue : TeamColour.Red;
@@ -169,11 +170,11 @@ namespace osu.Game.Tournament.Screens.MapPool
                     addForBeatmap(map.Beatmap.OnlineID);
                 else
                 {
-                    var existing = CurrentMatch.Value.PicksBans.FirstOrDefault(p => p.BeatmapID == map.Beatmap?.OnlineID);
+                    var existing = CurrentMatch.Value?.PicksBans.FirstOrDefault(p => p.BeatmapID == map.Beatmap?.OnlineID);
 
                     if (existing != null)
                     {
-                        CurrentMatch.Value.PicksBans.Remove(existing);
+                        CurrentMatch.Value?.PicksBans.Remove(existing);
                         setNextMode();
                     }
                 }
@@ -186,13 +187,13 @@ namespace osu.Game.Tournament.Screens.MapPool
 
         private void reset()
         {
-            CurrentMatch.Value.PicksBans.Clear();
+            CurrentMatch.Value?.PicksBans.Clear();
             setNextMode();
         }
 
         private void addForBeatmap(int beatmapId)
         {
-            if (CurrentMatch.Value == null)
+            if (CurrentMatch.Value?.Round.Value == null)
                 return;
 
             if (CurrentMatch.Value.Round.Value.Beatmaps.All(b => b.Beatmap?.OnlineID != beatmapId))
@@ -228,7 +229,7 @@ namespace osu.Game.Tournament.Screens.MapPool
             base.Hide();
         }
 
-        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch> match)
+        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             base.CurrentMatchChanged(match);
             updateDisplay();
@@ -245,8 +246,8 @@ namespace osu.Game.Tournament.Screens.MapPool
 
             if (CurrentMatch.Value.Round.Value != null)
             {
-                FillFlowContainer<TournamentBeatmapPanel> currentFlow = null;
+                FillFlowContainer<TournamentBeatmapPanel>? currentFlow = null;
-                string currentMods = null;
+                string? currentMods = null;
                 int flowCount = 0;
 
                 foreach (var b in CurrentMatch.Value.Round.Value.Beatmaps)

osu.Game.Tournament/Screens/Schedule/ScheduleScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using osu.Framework.Allocation;
@@ -21,9 +19,9 @@ namespace osu.Game.Tournament.Screens.Schedule
 {
     public partial class ScheduleScreen : TournamentScreen
     {
-        private readonly Bindable<TournamentMatch> currentMatch = new Bindable<TournamentMatch>();
+        private readonly Bindable<TournamentMatch?> currentMatch = new Bindable<TournamentMatch?>();
-        private Container mainContainer;
+        private Container mainContainer = null!;
-        private LadderInfo ladder;
+        private LadderInfo ladder = null!;
 
         [BackgroundDependencyLoader]
         private void load(LadderInfo ladder)
@@ -107,7 +105,7 @@ namespace osu.Game.Tournament.Screens.Schedule
             currentMatch.BindValueChanged(matchChanged, true);
         }
 
-        private void matchChanged(ValueChangedEvent<TournamentMatch> match)
+        private void matchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             var upcoming = ladder.Matches.Where(p => !p.Completed.Value && p.Team1.Value != null && p.Team2.Value != null && Math.Abs(p.Date.Value.DayOfYear - DateTimeOffset.UtcNow.DayOfYear) < 4);
             var conditionals = ladder

osu.Game.Tournament/Screens/Setup/ResolutionSelector.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using osu.Framework.Graphics;
 using osu.Game.Graphics.UserInterface;
@@ -14,9 +12,9 @@ namespace osu.Game.Tournament.Screens.Setup
         private const int minimum_window_height = 480;
         private const int maximum_window_height = 2160;
 
-        public new Action<int> Action;
+        public new Action<int>? Action;
 
-        private OsuNumberBox numberBox;
+        private OsuNumberBox? numberBox;
 
         protected override Drawable CreateComponent()
         {

osu.Game.Tournament/Screens/Setup/SetupScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Drawing;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -24,27 +22,27 @@ namespace osu.Game.Tournament.Screens.Setup
 {
     public partial class SetupScreen : TournamentScreen
     {
-        private FillFlowContainer fillFlow;
+        private FillFlowContainer fillFlow = null!;
 
-        private LoginOverlay loginOverlay;
+        private LoginOverlay? loginOverlay;
-        private ResolutionSelector resolution;
+        private ResolutionSelector resolution = null!;
 
         [Resolved]
-        private MatchIPCInfo ipc { get; set; }
+        private MatchIPCInfo ipc { get; set; } = null!;
 
         [Resolved]
-        private StableInfo stableInfo { get; set; }
+        private StableInfo stableInfo { get; set; } = null!;
 
         [Resolved]
-        private IAPIProvider api { get; set; }
+        private IAPIProvider api { get; set; } = null!;
 
         [Resolved]
-        private RulesetStore rulesets { get; set; }
+        private RulesetStore rulesets { get; set; } = null!;
 
-        [Resolved(canBeNull: true)]
+        [Resolved]
-        private TournamentSceneManager sceneManager { get; set; }
+        private TournamentSceneManager? sceneManager { get; set; }
 
-        private Bindable<Size> windowSize;
+        private Bindable<Size> windowSize = null!;
 
         [BackgroundDependencyLoader]
         private void load(FrameworkConfigManager frameworkConfig)
@@ -115,7 +113,7 @@ namespace osu.Game.Tournament.Screens.Setup
                     Failing = api.IsLoggedIn != true,
                     Description = "In order to access the API and display metadata, signing in is required."
                 },
-                new LabelledDropdown<RulesetInfo>
+                new LabelledDropdown<RulesetInfo?>
                 {
                     Label = "Ruleset",
                     Description = "Decides what stats are displayed and which ranks are retrieved for players. This requires a restart to reload data for an existing bracket.",

osu.Game.Tournament/Screens/Setup/StablePathSelectScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.IO;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
@@ -23,20 +21,20 @@ namespace osu.Game.Tournament.Screens.Setup
 {
     public partial class StablePathSelectScreen : TournamentScreen
     {
-        [Resolved(canBeNull: true)]
+        [Resolved]
-        private TournamentSceneManager sceneManager { get; set; }
+        private TournamentSceneManager? sceneManager { get; set; }
 
         [Resolved]
-        private MatchIPCInfo ipc { get; set; }
+        private MatchIPCInfo ipc { get; set; } = null!;
 
-        private OsuDirectorySelector directorySelector;
+        private OsuDirectorySelector directorySelector = null!;
-        private DialogOverlay overlay;
+        private DialogOverlay? overlay;
 
         [BackgroundDependencyLoader(true)]
         private void load(Storage storage, OsuColour colours)
         {
             var initialStorage = (ipc as FileBasedIPC)?.IPCStorage ?? storage;
-            string initialPath = new DirectoryInfo(initialStorage.GetFullPath(string.Empty)).Parent?.FullName;
+            string? initialPath = new DirectoryInfo(initialStorage.GetFullPath(string.Empty)).Parent?.FullName;
 
             AddRangeInternal(new Drawable[]
             {

osu.Game.Tournament/Screens/Setup/TournamentSwitcher.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Graphics.UserInterface;
@@ -13,12 +11,12 @@ namespace osu.Game.Tournament.Screens.Setup
 {
     internal partial class TournamentSwitcher : ActionableInfo
     {
-        private OsuDropdown<string> dropdown;
+        private OsuDropdown<string> dropdown = null!;
-        private OsuButton folderButton;
+        private OsuButton folderButton = null!;
-        private OsuButton reloadTournamentsButton;
+        private OsuButton reloadTournamentsButton = null!;
 
         [Resolved]
-        private TournamentGameBase game { get; set; }
+        private TournamentGameBase game { get; set; } = null!;
 
         [BackgroundDependencyLoader]
         private void load(TournamentStorage storage)

osu.Game.Tournament/Screens/Showcase/ShowcaseScreen.cs

@@ -42,7 +42,7 @@ namespace osu.Game.Tournament.Screens.Showcase
             });
         }
 
-        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch> match)
+        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             // showcase screen doesn't care about a match being selected.
             // base call intentionally omitted to not show match warning.

osu.Game.Tournament/Screens/TeamIntro/SeedingScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Diagnostics;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -22,12 +20,12 @@ namespace osu.Game.Tournament.Screens.TeamIntro
 {
     public partial class SeedingScreen : TournamentMatchScreen
     {
-        private Container mainContainer;
+        private Container mainContainer = null!;
 
-        private readonly Bindable<TournamentTeam> currentTeam = new Bindable<TournamentTeam>();
+        private readonly Bindable<TournamentTeam?> currentTeam = new Bindable<TournamentTeam?>();
 
-        private TourneyButton showFirstTeamButton;
+        private TourneyButton showFirstTeamButton = null!;
-        private TourneyButton showSecondTeamButton;
+        private TourneyButton showSecondTeamButton = null!;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -53,13 +51,13 @@ namespace osu.Game.Tournament.Screens.TeamIntro
                         {
                             RelativeSizeAxes = Axes.X,
                             Text = "Show first team",
-                            Action = () => currentTeam.Value = CurrentMatch.Value.Team1.Value,
+                            Action = () => currentTeam.Value = CurrentMatch.Value?.Team1.Value,
                         },
                         showSecondTeamButton = new TourneyButton
                         {
                             RelativeSizeAxes = Axes.X,
                             Text = "Show second team",
-                            Action = () => currentTeam.Value = CurrentMatch.Value.Team2.Value,
+                            Action = () => currentTeam.Value = CurrentMatch.Value?.Team2.Value,
                         },
                         new SettingsTeamDropdown(LadderInfo.Teams)
                         {
@@ -73,7 +71,7 @@ namespace osu.Game.Tournament.Screens.TeamIntro
             currentTeam.BindValueChanged(teamChanged, true);
         }
 
-        private void teamChanged(ValueChangedEvent<TournamentTeam> team) => updateTeamDisplay();
+        private void teamChanged(ValueChangedEvent<TournamentTeam?> team) => updateTeamDisplay();
 
         public override void Show()
         {
@@ -84,7 +82,7 @@ namespace osu.Game.Tournament.Screens.TeamIntro
             updateTeamDisplay();
         }
 
-        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch> match)
+        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             base.CurrentMatchChanged(match);
 
@@ -256,7 +254,7 @@ namespace osu.Game.Tournament.Screens.TeamIntro
 
         private partial class LeftInfo : CompositeDrawable
         {
-            public LeftInfo(TournamentTeam team)
+            public LeftInfo(TournamentTeam? team)
             {
                 FillFlowContainer fill;
 
@@ -315,7 +313,7 @@ namespace osu.Game.Tournament.Screens.TeamIntro
 
             private partial class TeamDisplay : DrawableTournamentTeam
             {
-                public TeamDisplay(TournamentTeam team)
+                public TeamDisplay(TournamentTeam? team)
                     : base(team)
                 {
                     AutoSizeAxes = Axes.Both;

osu.Game.Tournament/Screens/TeamIntro/TeamIntroScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -15,7 +13,7 @@ namespace osu.Game.Tournament.Screens.TeamIntro
 {
     public partial class TeamIntroScreen : TournamentMatchScreen
     {
-        private Container mainContainer;
+        private Container mainContainer = null!;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -36,7 +34,7 @@ namespace osu.Game.Tournament.Screens.TeamIntro
             };
         }
 
-        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch> match)
+        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             base.CurrentMatchChanged(match);
 

osu.Game.Tournament/Screens/TeamWin/TeamWinScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -16,12 +14,12 @@ namespace osu.Game.Tournament.Screens.TeamWin
 {
     public partial class TeamWinScreen : TournamentMatchScreen
     {
-        private Container mainContainer;
+        private Container mainContainer = null!;
 
         private readonly Bindable<bool> currentCompleted = new Bindable<bool>();
 
-        private TourneyVideo blueWinVideo;
+        private TourneyVideo blueWinVideo = null!;
-        private TourneyVideo redWinVideo;
+        private TourneyVideo redWinVideo = null!;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -51,7 +49,7 @@ namespace osu.Game.Tournament.Screens.TeamWin
             currentCompleted.BindValueChanged(_ => update());
         }
 
-        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch> match)
+        protected override void CurrentMatchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             base.CurrentMatchChanged(match);
 
@@ -70,7 +68,7 @@ namespace osu.Game.Tournament.Screens.TeamWin
         {
             var match = CurrentMatch.Value;
 
-            if (match.Winner == null)
+            if (match?.Winner == null)
             {
                 mainContainer.Clear();
                 return;

osu.Game.Tournament/Screens/TournamentMatchScreen.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using osu.Framework.Bindables;
 using osu.Game.Tournament.Models;
 
@@ -10,8 +8,8 @@ namespace osu.Game.Tournament.Screens
 {
     public abstract partial class TournamentMatchScreen : TournamentScreen
     {
-        protected readonly Bindable<TournamentMatch> CurrentMatch = new Bindable<TournamentMatch>();
+        protected readonly Bindable<TournamentMatch?> CurrentMatch = new Bindable<TournamentMatch?>();
-        private WarningBox noMatchWarning;
+        private WarningBox? noMatchWarning;
 
         protected override void LoadComplete()
         {
@@ -21,7 +19,7 @@ namespace osu.Game.Tournament.Screens
             CurrentMatch.BindValueChanged(CurrentMatchChanged, true);
         }
 
-        protected virtual void CurrentMatchChanged(ValueChangedEvent<TournamentMatch> match)
+        protected virtual void CurrentMatchChanged(ValueChangedEvent<TournamentMatch?> match)
         {
             if (match.NewValue == null)
             {

osu.Game.Tournament/TournamentGame.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System.Drawing;
 using System.Linq;
 using osu.Framework.Allocation;
@@ -35,12 +33,12 @@ namespace osu.Game.Tournament
         public static readonly Color4 ELEMENT_FOREGROUND_COLOUR = Color4Extensions.FromHex("#000");
 
         public static readonly Color4 TEXT_COLOUR = Color4Extensions.FromHex("#fff");
-        private Drawable heightWarning;
+        private Drawable heightWarning = null!;
 
-        private Bindable<WindowMode> windowMode;
+        private Bindable<WindowMode> windowMode = null!;
         private readonly BindableSize windowSize = new BindableSize();
 
-        private LoadingSpinner loadingSpinner;
+        private LoadingSpinner loadingSpinner = null!;
 
         [Cached(typeof(IDialogOverlay))]
         private readonly DialogOverlay dialogOverlay = new DialogOverlay();

osu.Game.Tournament/TournamentGameBase.cs

@@ -1,14 +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.
 
-#nullable disable
-
 using System;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Newtonsoft.Json;
 using osu.Framework.Allocation;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.Input;
@@ -31,11 +30,11 @@ namespace osu.Game.Tournament
     public partial class TournamentGameBase : OsuGameBase
     {
         public const string BRACKET_FILENAME = @"bracket.json";
-        private LadderInfo ladder;
+        private LadderInfo ladder = new LadderInfo();
-        private TournamentStorage storage;
+        private TournamentStorage storage = null!;
-        private DependencyContainer dependencies;
+        private DependencyContainer dependencies = null!;
-        private FileBasedIPC ipc;
+        private FileBasedIPC ipc = null!;
-        private BeatmapLookupCache beatmapCache;
+        private BeatmapLookupCache beatmapCache = null!;
 
         protected Task BracketLoadTask => bracketLoadTaskCompletionSource.Task;
 
@@ -54,7 +53,7 @@ namespace osu.Game.Tournament
             return new ProductionEndpointConfiguration();
         }
 
-        private TournamentSpriteText initialisationText;
+        private TournamentSpriteText initialisationText = null!;
 
         [BackgroundDependencyLoader]
         private void load(Storage baseStorage)
@@ -100,11 +99,11 @@ namespace osu.Game.Tournament
                 {
                     using (Stream stream = storage.GetStream(BRACKET_FILENAME, FileAccess.Read, FileMode.Open))
                     using (var sr = new StreamReader(stream))
-                        ladder = JsonConvert.DeserializeObject<LadderInfo>(await sr.ReadToEndAsync().ConfigureAwait(false), new JsonPointConverter());
+                    {
+                        ladder = JsonConvert.DeserializeObject<LadderInfo>(await sr.ReadToEndAsync().ConfigureAwait(false), new JsonPointConverter()) ?? ladder;
+                    }
                 }
 
-                ladder ??= new LadderInfo();
-
                 var resolvedRuleset = ladder.Ruleset.Value != null
                     ? RulesetStore.GetRuleset(ladder.Ruleset.Value.ShortName)
                     : RulesetStore.AvailableRulesets.First();
@@ -283,7 +282,7 @@ namespace osu.Game.Tournament
 
         private void updateLoadProgressMessage(string s) => Schedule(() => initialisationText.Text = s);
 
-        public void PopulatePlayer(TournamentUser user, Action success = null, Action failure = null, bool immediate = false)
+        public void PopulatePlayer(TournamentUser user, Action? success = null, Action? failure = null, bool immediate = false)
         {
             var req = new GetUserRequest(user.OnlineID, ladder.Ruleset.Value);
 
@@ -348,8 +347,8 @@ namespace osu.Game.Tournament
             foreach (var r in ladder.Rounds)
                 r.Matches = ladder.Matches.Where(p => p.Round.Value == r).Select(p => p.ID).ToList();
 
-            ladder.Progressions = ladder.Matches.Where(p => p.Progression.Value != null).Select(p => new TournamentProgression(p.ID, p.Progression.Value.ID)).Concat(
+            ladder.Progressions = ladder.Matches.Where(p => p.Progression.Value != null).Select(p => new TournamentProgression(p.ID, p.Progression.Value.AsNonNull().ID)).Concat(
-                                            ladder.Matches.Where(p => p.LosersProgression.Value != null).Select(p => new TournamentProgression(p.ID, p.LosersProgression.Value.ID, true)))
+                                            ladder.Matches.Where(p => p.LosersProgression.Value != null).Select(p => new TournamentProgression(p.ID, p.LosersProgression.Value.AsNonNull().ID, true)))
                                         .ToList();
 
             return JsonConvert.SerializeObject(ladder,

osu.Game.Tournament/TournamentSceneManager.cs

@@ -1,8 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
 using System;
 using System.Linq;
 using osu.Framework.Allocation;
@@ -35,8 +33,8 @@ namespace osu.Game.Tournament
     [Cached]
     public partial class TournamentSceneManager : CompositeDrawable
     {
-        private Container screens;
+        private Container screens = null!;
-        private TourneyVideo video;
+        private TourneyVideo video = null!;
 
         public const int CONTROL_AREA_WIDTH = 200;
 
@@ -50,8 +48,8 @@ namespace osu.Game.Tournament
         [Cached]
         private TournamentMatchChatDisplay chat = new TournamentMatchChatDisplay();
 
-        private Container chatContainer;
+        private Container chatContainer = null!;
-        private FillFlowContainer buttons;
+        private FillFlowContainer buttons = null!;
 
         public TournamentSceneManager()
         {
@@ -166,10 +164,10 @@ namespace osu.Game.Tournament
 
         private float depth;
 
-        private Drawable currentScreen;
+        private Drawable? currentScreen;
-        private ScheduledDelegate scheduledHide;
+        private ScheduledDelegate? scheduledHide;
 
-        private Drawable temporaryScreen;
+        private Drawable? temporaryScreen;
 
         public void SetScreen(Drawable screen)
         {
@@ -284,7 +282,7 @@ namespace osu.Game.Tournament
                                 Y = -2,
                                 Anchor = Anchor.Centre,
                                 Origin = Anchor.Centre,
-                                Text = shortcutKey.ToString(),
+                                Text = shortcutKey.Value.ToString(),
                             }
                         }
                     });
@@ -304,7 +302,7 @@ namespace osu.Game.Tournament
 
             private bool isSelected;
 
-            public Action<Type> RequestSelection;
+            public Action<Type>? RequestSelection;
 
             public bool IsSelected
             {