Merge pull request #21629 from peppy/guard-url-protocols

Update framework

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
         run: dotnet tool restore
 
       - name: Restore Packages
-        run: dotnet restore
+        run: dotnet restore osu.Desktop.slnf
 
       - name: Restore inspectcode cache
         uses: actions/cache@v3
@@ -113,27 +113,36 @@ jobs:
         with:
           dotnet-version: "6.0.x"
 
-      - name: Setup MSBuild
+      - name: Install .NET workloads
-        uses: microsoft/setup-msbuild@v1
+        run: dotnet workload install maui-android
 
-      - name: Build
+      - name: Compile
-        run: msbuild osu.Android/osu.Android.csproj /restore /p:Configuration=Debug
+        run: dotnet build -c Debug osu.Android.slnf
 
   build-only-ios:
     name: Build only (iOS)
-    runs-on: macos-latest
+    # change to macos-latest once GitHub finishes migrating all repositories to macOS 12.
+    runs-on: macos-12
     timeout-minutes: 60
     steps:
       - name: Checkout
         uses: actions/checkout@v2
 
+      # see https://github.com/actions/runner-images/issues/6771#issuecomment-1354713617
+      # remove once all workflow VMs use Xcode 14.1
+      - name: Set Xcode Version
+        shell: bash
+        run: |
+          sudo xcode-select -s "/Applications/Xcode_14.1.app"
+          echo "MD_APPLE_SDK_ROOT=/Applications/Xcode_14.1.app" >> $GITHUB_ENV
+
       - name: Install .NET 6.0.x
         uses: actions/setup-dotnet@v1
         with:
           dotnet-version: "6.0.x"
 
-      # Contrary to seemingly any other msbuild, msbuild running on macOS/Mono
+      - name: Install .NET Workloads
-      # cannot accept .sln(f) files as arguments.
+        run: dotnet workload install maui-ios
-      # Build just the main game for now.
+
       - name: Build
-        run: msbuild osu.iOS/osu.iOS.csproj /restore /p:Configuration=Debug
+        run: dotnet build -c Debug osu.iOS

README.md

@@ -32,7 +32,7 @@ If you are looking to install or test osu! without setting up a development envi
 
 **Latest build:**
 
-| [Windows 8.1+ (x64)](https://github.com/ppy/osu/releases/latest/download/install.exe) | macOS 10.15+ ([Intel](https://github.com/ppy/osu/releases/latest/download/osu.app.Intel.zip), [Apple Silicon](https://github.com/ppy/osu/releases/latest/download/osu.app.Apple.Silicon.zip)) | [Linux (x64)](https://github.com/ppy/osu/releases/latest/download/osu.AppImage) | [iOS 10+](https://osu.ppy.sh/home/testflight) | [Android 5+](https://github.com/ppy/osu/releases/latest/download/sh.ppy.osulazer.apk) |
+| [Windows 8.1+ (x64)](https://github.com/ppy/osu/releases/latest/download/install.exe) | macOS 10.15+ ([Intel](https://github.com/ppy/osu/releases/latest/download/osu.app.Intel.zip), [Apple Silicon](https://github.com/ppy/osu/releases/latest/download/osu.app.Apple.Silicon.zip)) | [Linux (x64)](https://github.com/ppy/osu/releases/latest/download/osu.AppImage) | [iOS 13.4+](https://osu.ppy.sh/home/testflight) | [Android 5+](https://github.com/ppy/osu/releases/latest/download/sh.ppy.osulazer.apk) |
 | ------------- | ------------- | ------------- | ------------- | ------------- |
 
 - The iOS testflight link may fill up (Apple has a hard limit of 10,000 users). We reset it occasionally when this happens. Please do not ask about this. Check back regularly for link resets or follow [peppy](https://twitter.com/ppy) on twitter for announcements of link resets.

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <AssemblyTitle>osu.Game.Rulesets.EmptyFreeform</AssemblyTitle>
     <OutputType>Library</OutputType>
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -12,4 +12,4 @@
   <ItemGroup>
     <ProjectReference Include="..\..\..\..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
-</Project>
+</Project>

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <AssemblyTitle>osu.Game.Rulesets.Pippidon</AssemblyTitle>
     <OutputType>Library</OutputType>
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -12,4 +12,4 @@
   <ItemGroup>
     <ProjectReference Include="..\..\..\..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
-</Project>
+</Project>

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <AssemblyTitle>osu.Game.Rulesets.EmptyScrolling</AssemblyTitle>
     <OutputType>Library</OutputType>
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -12,4 +12,4 @@
   <ItemGroup>
     <ProjectReference Include="..\..\..\..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
-</Project>
+</Project>

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <AssemblyTitle>osu.Game.Rulesets.Pippidon</AssemblyTitle>
     <OutputType>Library</OutputType>
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -12,4 +12,4 @@
   <ItemGroup>
     <ProjectReference Include="..\..\..\..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
-</Project>
+</Project>

appveyor.yml

@@ -1,6 +1,6 @@
 clone_depth: 1
 version: '{branch}-{build}'
-image: Visual Studio 2019
+image: Visual Studio 2022
 cache:
   - '%LOCALAPPDATA%\NuGet\v3-cache -> appveyor.yml'
 
@@ -11,6 +11,8 @@ dotnet_csproj:
 
 before_build:
   - cmd: dotnet --info # Useful when version mismatch between CI and local
+  - cmd: dotnet workload install maui-android # Change to `dotnet workload restore` once there's no old projects
+  - cmd: dotnet workload install maui-ios # Change to `dotnet workload restore` once there's no old projects
   - cmd: nuget restore -verbosity quiet # Only nuget.exe knows both new (.NET Core) and old (Xamarin) projects
 
 build:

global.json

@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "6.0.300",
+    "rollForward": "major"
+  }
+}

osu.Android.props

@@ -1,58 +1,16 @@
 <Project>
   <PropertyGroup>
-    <LangVersion>8.0</LangVersion>
+    <SupportedOSPlatformVersion>21.0</SupportedOSPlatformVersion>
-    <OutputPath>bin\$(Configuration)</OutputPath>
+    <RuntimeIdentifiers>android-x86;android-arm;android-arm64</RuntimeIdentifiers>
-    <WarningLevel>4</WarningLevel>
+    <AndroidPackageFormat>apk</AndroidPackageFormat>
-    <SchemaVersion>2.0</SchemaVersion>
+    <MandroidI18n>CJK;Mideast;Rare;West;Other;</MandroidI18n>
-    <BundleAssemblies>false</BundleAssemblies>
+    <AndroidHttpClientHandlerType>Xamarin.Android.Net.AndroidMessageHandler</AndroidHttpClientHandlerType>
-    <AotAssemblies>false</AotAssemblies>
+    <!-- NullabilityInfoContextSupport is disabled by default for Android -->
-    <OutputType>Library</OutputType>
+    <NullabilityInfoContextSupport>true</NullabilityInfoContextSupport>
-    <FileAlignment>512</FileAlignment>
-    <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
-    <AndroidApplication>True</AndroidApplication>
-    <AndroidHttpClientHandlerType>Xamarin.Android.Net.AndroidClientHandler</AndroidHttpClientHandlerType>
-    <TargetFrameworkVersion>v10.0</TargetFrameworkVersion>
-    <AndroidUseLatestPlatformSdk>false</AndroidUseLatestPlatformSdk>
-    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <AndroidSupportedAbis>armeabi-v7a;x86;arm64-v8a</AndroidSupportedAbis>
-    <AndroidEnableSGenConcurrent>true</AndroidEnableSGenConcurrent>
-    <MandroidI18n>cjk,mideast,other,rare,west</MandroidI18n>
-    <AndroidLinkMode>SdkOnly</AndroidLinkMode>
-    <ErrorReport>prompt</ErrorReport>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)' == 'Debug'">
-    <DebugSymbols>True</DebugSymbols>
-    <DebugType>portable</DebugType>
-    <Optimize>False</Optimize>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <AndroidManagedSymbols>false</AndroidManagedSymbols>
-    <AndroidUseSharedRuntime>true</AndroidUseSharedRuntime>
-    <EmbedAssembliesIntoApk>false</EmbedAssembliesIntoApk>
-  </PropertyGroup>
-  <PropertyGroup Condition="'$(Configuration)' == 'Release'">
-    <DebugSymbols>false</DebugSymbols>
-    <DebugType>None</DebugType>
-    <Optimize>True</Optimize>
-    <AndroidManagedSymbols>false</AndroidManagedSymbols>
-    <AndroidUseSharedRuntime>False</AndroidUseSharedRuntime>
     <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
   </PropertyGroup>
   <ItemGroup>
-    <None Include="$(MSBuildThisFileDirectory)\osu.licenseheader">
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.1216.1" />
-      <Link>osu.licenseheader</Link>
-    </None>
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="System" />
-    <Reference Include="System.Net.Http" />
-    <Reference Include="System.Xml" />
-    <Reference Include="System.Core" />
-    <Reference Include="Mono.Android" />
-    <Reference Include="Java.Interop" />
-  </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.1207.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.1208.0" />
   </ItemGroup>
   <ItemGroup Label="Transitive Dependencies">
     <!-- Realm needs to be directly referenced in all Xamarin projects, as it will not pull in its transitive dependencies otherwise. -->
@@ -61,4 +19,9 @@
   <ItemGroup>
     <LinkDescription Include="$(MSBuildThisFileDirectory)\osu.Android\Linker.xml"/>
   </ItemGroup>
+  <PropertyGroup>
+    <!-- Fody does not handle Android build well, and warns when unchanged.
+         Since Realm objects are not declared directly in Android projects, simply disable Fody. -->
+    <DisableFody>true</DisableFody>
+  </PropertyGroup>
 </Project>

osu.Android/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" package="sh.ppy.osulazer" android:installLocation="auto" android:versionName="0.1.0">
-	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="29" />
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" />
 	<application android:allowBackup="true" android:supportsRtl="true" android:label="osu!" android:icon="@drawable/lazer" />
 </manifest>

osu.Android/OsuGameActivity.cs

@@ -7,6 +7,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using System.Threading.Tasks;
 using Android.App;
 using Android.Content;
@@ -74,11 +75,23 @@ namespace osu.Android
             Debug.Assert(Resources?.DisplayMetrics != null);
 
             Point displaySize = new Point();
+#pragma warning disable 618 // GetSize is deprecated
             WindowManager.DefaultDisplay.GetSize(displaySize);
+#pragma warning restore 618
             float smallestWidthDp = Math.Min(displaySize.X, displaySize.Y) / Resources.DisplayMetrics.Density;
             bool isTablet = smallestWidthDp >= 600f;
 
             RequestedOrientation = DefaultOrientation = isTablet ? ScreenOrientation.FullUser : ScreenOrientation.SensorLandscape;
+
+            // Currently (SDK 6.0.200), BundleAssemblies is not runnable for net6-android.
+            // The assembly files are not available as files either after native AOT.
+            // Manually load them so that they can be loaded by RulesetStore.loadFromAppDomain.
+            // REMEMBER to fully uninstall previous version every time when investigating this!
+            // Don't forget osu.Game.Tests.Android too.
+            Assembly.Load("osu.Game.Rulesets.Osu");
+            Assembly.Load("osu.Game.Rulesets.Taiko");
+            Assembly.Load("osu.Game.Rulesets.Catch");
+            Assembly.Load("osu.Game.Rulesets.Mania");
         }
 
         protected override void OnNewIntent(Intent intent) => handleIntent(intent);
@@ -127,7 +140,7 @@ namespace osu.Android
 
                 cursor.MoveToFirst();
 
-                int filenameColumn = cursor.GetColumnIndex(OpenableColumns.DisplayName);
+                int filenameColumn = cursor.GetColumnIndex(IOpenableColumns.DisplayName);
                 string filename = cursor.GetString(filenameColumn);
 
                 // SharpCompress requires archive streams to be seekable, which the stream opened by

osu.Android/OsuGameAndroid.cs

@@ -5,7 +5,7 @@
 
 using System;
 using Android.App;
-using Android.OS;
+using Microsoft.Maui.Devices;
 using osu.Framework.Allocation;
 using osu.Framework.Android.Input;
 using osu.Framework.Input.Handlers;
@@ -14,7 +14,6 @@ using osu.Game;
 using osu.Game.Overlays.Settings;
 using osu.Game.Updater;
 using osu.Game.Utils;
-using Xamarin.Essentials;
 
 namespace osu.Android
 {
@@ -48,7 +47,7 @@ namespace osu.Android
                     // https://stackoverflow.com/questions/52977079/android-sdk-28-versioncode-in-packageinfo-has-been-deprecated
                     string versionName = string.Empty;
 
-                    if (Build.VERSION.SdkInt >= BuildVersionCodes.P)
+                    if (OperatingSystem.IsAndroidVersionAtLeast(28))
                     {
                         versionName = packageInfo.LongVersionCode.ToString();
                         // ensure we only read the trailing portion of long (the part we are interested in).

osu.Android/osu.Android.csproj

@@ -1,73 +1,19 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\osu.Android.props" />
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <TargetFramework>net6.0-android</TargetFramework>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <OutputType>Exe</OutputType>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>{D1D5F9A8-B40B-40E6-B02F-482D03346D3D}</ProjectGuid>
-    <ProjectTypeGuids>{EFBA0AD7-5A72-4C68-AF49-83D382785DCF};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <TemplateGuid>{122416d6-6b49-4ee2-a1e8-b825f31c79fe}</TemplateGuid>
     <RootNamespace>osu.Android</RootNamespace>
     <AssemblyName>osu.Android</AssemblyName>
-    <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
+    <UseMauiEssentials>true</UseMauiEssentials>
-    <AndroidSupportedAbis>armeabi-v7a;x86;arm64-v8a</AndroidSupportedAbis>
+    <!-- This currently causes random lockups during gameplay. https://github.com/mono/mono/issues/18973 -->
-    <EnableLLVM>false</EnableLLVM> <!-- This currently causes random lockups during gameplay. https://github.com/mono/mono/issues/18973 -->
+    <EnableLLVM>false</EnableLLVM>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <MandroidI18n>cjk;mideast;other;rare;west</MandroidI18n>
-    <AndroidDexTool>d8</AndroidDexTool>
-    <AndroidLinkTool>r8</AndroidLinkTool>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <AndroidLinkMode>None</AndroidLinkMode>
-    <MandroidI18n>cjk;mideast;other;rare;west</MandroidI18n>
-    <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="AndroidJoystickSettings.cs" />
+    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj" />
-    <Compile Include="AndroidMouseSettings.cs" />
+    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj" />
-    <Compile Include="GameplayScreenRotationLocker.cs" />
+    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj" />
-    <Compile Include="OsuGameActivity.cs" />
+    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
-    <Compile Include="OsuGameAndroid.cs" />
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
-  <ItemGroup>
+</Project>
-    <None Include="Properties\AndroidManifest.xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj">
-      <Project>{58f6c80c-1253-4a0e-a465-b8c85ebeadf3}</Project>
-      <Name>osu.Game.Rulesets.Catch</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj">
-      <Project>{48f4582b-7687-4621-9cbe-5c24197cb536}</Project>
-      <Name>osu.Game.Rulesets.Mania</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj">
-      <Project>{c92a607b-1fdd-4954-9f92-03ff547d9080}</Project>
-      <Name>osu.Game.Rulesets.Osu</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj">
-      <Project>{f167e17a-7de6-4af5-b920-a5112296c695}</Project>
-      <Name>osu.Game.Rulesets.Taiko</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
-      <Project>{2a66dd92-adb1-4994-89e2-c94e04acda0d}</Project>
-      <Name>osu.Game</Name>
-    </ProjectReference>
-  </ItemGroup>
-  <ItemGroup>
-    <AndroidResource Include="Resources\drawable\lazer.png" />
-  </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="System.Formats.Asn1">
-      <Version>5.0.0</Version>
-    </PackageReference>
-  </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="Xamarin.Essentials" Version="1.7.0" />
-  </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
-</Project>

osu.Game.Rulesets.Catch.Tests.Android/AndroidManifest.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- using a different name because package name cannot contain 'catch' -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="osu.Game.Rulesets.Catch_Tests.Android" android:installLocation="auto">
-	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="29" />
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" />
 	<application android:allowBackup="true" android:supportsRtl="true" android:label="osu!catch Test" />
 </manifest>

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

@@ -1,49 +1,24 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\osu.Android.props" />
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <TargetFramework>net6.0-android</TargetFramework>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <OutputType>Exe</OutputType>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>{C5379ECB-3A94-4D2F-AC3B-2615AC23EB0D}</ProjectGuid>
-    <ProjectTypeGuids>{EFBA0AD7-5A72-4C68-AF49-83D382785DCF};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <TemplateGuid>{122416d6-6b49-4ee2-a1e8-b825f31c79fe}</TemplateGuid>
     <RootNamespace>osu.Game.Rulesets.Catch.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Catch.Tests.Android</AssemblyName>
-    <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
-    <AndroidSupportedAbis>armeabi-v7a;x86;arm64-v8a</AndroidSupportedAbis>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <AndroidLinkMode>None</AndroidLinkMode>
-    <MandroidI18n>cjk;mideast;other;rare;west</MandroidI18n>
-    <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="MainActivity.cs" />
+    <Compile Include="..\osu.Game.Rulesets.Catch.Tests\**\*.cs" Exclude="**\obj\**">
-  </ItemGroup>
-  <ItemGroup>
-    <None Include="Properties\AndroidManifest.xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="..\osu.Game.Rulesets.Catch.Tests\*.cs">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
+    <!-- TargetPath is relative to RootNamespace,
+         and DllResourceStore is relative to AssemblyName. -->
+    <EmbeddedResource Include="..\osu.Game.Rulesets.Catch.Tests\**\Resources\**\*">
+      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
+      <TargetPath>Android\%(RecursiveDir)%(Filename)%(Extension)</TargetPath>
+    </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj">
+    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj" />
-      <Project>{58f6c80c-1253-4a0e-a465-b8c85ebeadf3}</Project>
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Name>osu.Game.Rulesets.Catch</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
-      <Project>{2A66DD92-ADB1-4994-89E2-C94E04ACDA0D}</Project>
-      <Name>osu.Game</Name>
-    </ProjectReference>
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="System.Formats.Asn1">
-      <Version>5.0.0</Version>
-    </PackageReference>
-  </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
 </Project>

osu.Game.Rulesets.Catch.Tests.iOS/Application.cs

@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using osu.Framework.iOS;
 using UIKit;
 
 namespace osu.Game.Rulesets.Catch.Tests.iOS
@@ -12,7 +11,7 @@ namespace osu.Game.Rulesets.Catch.Tests.iOS
     {
         public static void Main(string[] args)
         {
-            UIApplication.Main(args, typeof(GameUIApplication), typeof(AppDelegate));
+            UIApplication.Main(args, null, typeof(AppDelegate));
         }
     }
 }

osu.Game.Rulesets.Catch.Tests.iOS/Info.plist

@@ -13,7 +13,7 @@
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>MinimumOSVersion</key>
-	<string>10.0</string>
+	<string>13.4</string>
 	<key>UIDeviceFamily</key>
 	<array>
 		<integer>1</integer>

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

@@ -1,35 +1,19 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
-    <ProjectGuid>{4004C7B7-1A62-43F1-9DF2-52450FA67E70}</ProjectGuid>
     <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0-ios</TargetFramework>
+    <SupportedOSPlatformVersion>13.4</SupportedOSPlatformVersion>
     <RootNamespace>osu.Game.Rulesets.Catch.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Catch.Tests.iOS</AssemblyName>
   </PropertyGroup>
   <Import Project="..\osu.iOS.props" />
   <ItemGroup>
-    <None Include="Info.plist" />
-    <None Include="Entitlements.plist" />
-    <LinkDescription Include="..\osu.iOS\Linker.xml">
-      <Link>Linker.xml</Link>
-    </LinkDescription>
-    <Compile Include="Application.cs" />
-    <Compile Include="AppDelegate.cs" />
     <Compile Include="..\osu.Game.Rulesets.Catch.Tests\**\*.cs" Exclude="**\obj\**">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
   </ItemGroup>
   <ItemGroup Label="Project References">
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Project>{2A66DD92-ADB1-4994-89E2-C94E04ACDA0D}</Project>
+    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj" />
-      <Name>osu.Game</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj">
-      <Project>{58F6C80C-1253-4A0E-A465-B8C85EBEADF3}</Project>
-      <Name>osu.Game.Rulesets.Catch</Name>
-    </ProjectReference>
   </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
+</Project>
-</Project>

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

@@ -121,9 +121,7 @@ namespace osu.Game.Rulesets.Catch.Edit
                 return new SnapResult(originPosition, StartTime);
             }
 
-            return enumerateSnappingCandidates(time)
+            return enumerateSnappingCandidates(time).MinBy(pos => Vector2.DistanceSquared(screenSpacePosition, pos.ScreenSpacePosition));
-                   .OrderBy(pos => Vector2.DistanceSquared(screenSpacePosition, pos.ScreenSpacePosition))
-                   .FirstOrDefault();
         }
 
         private IEnumerable<SnapResult> enumerateSnappingCandidates(double time)

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <OutputType>Library</OutputType>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Description>catch the fruit. to the beat.</Description>
@@ -15,4 +15,4 @@
   <ItemGroup Label="Project References">
     <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
-</Project>
+</Project>

osu.Game.Rulesets.Mania.Tests.Android/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="osu.Game.Rulesets.Mania.Tests.Android" android:installLocation="auto">
-	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="29" />
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" />
 	<application android:allowBackup="true" android:supportsRtl="true" android:label="osu!mania Test" />
 </manifest>

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

@@ -1,49 +1,24 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\osu.Android.props" />
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <TargetFramework>net6.0-android</TargetFramework>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <OutputType>Exe</OutputType>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>{531F1092-DB27-445D-AA33-2A77C7187C99}</ProjectGuid>
-    <ProjectTypeGuids>{EFBA0AD7-5A72-4C68-AF49-83D382785DCF};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <TemplateGuid>{122416d6-6b49-4ee2-a1e8-b825f31c79fe}</TemplateGuid>
     <RootNamespace>osu.Game.Rulesets.Mania.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Mania.Tests.Android</AssemblyName>
-    <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
-    <AndroidSupportedAbis>armeabi-v7a;x86;arm64-v8a</AndroidSupportedAbis>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <AndroidLinkMode>None</AndroidLinkMode>
-    <MandroidI18n>cjk;mideast;other;rare;west</MandroidI18n>
-    <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="MainActivity.cs" />
+    <Compile Include="..\osu.Game.Rulesets.Mania.Tests\**\*.cs" Exclude="**\obj\**">
-  </ItemGroup>
-  <ItemGroup>
-    <None Include="Properties\AndroidManifest.xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="..\osu.Game.Rulesets.Mania.Tests\*.cs">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
+    <!-- TargetPath is relative to RootNamespace,
+         and DllResourceStore is relative to AssemblyName. -->
+    <EmbeddedResource Include="..\osu.Game.Rulesets.Mania.Tests\**\Resources\**\*">
+      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
+      <TargetPath>Android\%(RecursiveDir)%(Filename)%(Extension)</TargetPath>
+    </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj">
+    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj" />
-      <Project>{48f4582b-7687-4621-9cbe-5c24197cb536}</Project>
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Name>osu.Game.Rulesets.Mania</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
-      <Project>{2A66DD92-ADB1-4994-89E2-C94E04ACDA0D}</Project>
-      <Name>osu.Game</Name>
-    </ProjectReference>
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="System.Formats.Asn1">
-      <Version>5.0.0</Version>
-    </PackageReference>
-  </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
 </Project>

osu.Game.Rulesets.Mania.Tests.iOS/Application.cs

@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using osu.Framework.iOS;
 using UIKit;
 
 namespace osu.Game.Rulesets.Mania.Tests.iOS
@@ -12,7 +11,7 @@ namespace osu.Game.Rulesets.Mania.Tests.iOS
     {
         public static void Main(string[] args)
         {
-            UIApplication.Main(args, typeof(GameUIApplication), typeof(AppDelegate));
+            UIApplication.Main(args, null, typeof(AppDelegate));
         }
     }
 }

osu.Game.Rulesets.Mania.Tests.iOS/Info.plist

@@ -13,7 +13,7 @@
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>MinimumOSVersion</key>
-	<string>10.0</string>
+	<string>13.4</string>
 	<key>UIDeviceFamily</key>
 	<array>
 		<integer>1</integer>

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

@@ -1,35 +1,19 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
-    <ProjectGuid>{39FD990E-B6CE-4B2A-999F-BC008CF2C64C}</ProjectGuid>
     <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0-ios</TargetFramework>
+    <SupportedOSPlatformVersion>13.4</SupportedOSPlatformVersion>
     <RootNamespace>osu.Game.Rulesets.Mania.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Mania.Tests.iOS</AssemblyName>
   </PropertyGroup>
   <Import Project="..\osu.iOS.props" />
   <ItemGroup>
-    <None Include="Info.plist" />
-    <None Include="Entitlements.plist" />
-    <LinkDescription Include="..\osu.iOS\Linker.xml">
-      <Link>Linker.xml</Link>
-    </LinkDescription>
-    <Compile Include="Application.cs" />
-    <Compile Include="AppDelegate.cs" />
     <Compile Include="..\osu.Game.Rulesets.Mania.Tests\**\*.cs" Exclude="**\obj\**">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
   </ItemGroup>
   <ItemGroup Label="Project References">
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Project>{2A66DD92-ADB1-4994-89E2-C94E04ACDA0D}</Project>
+    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj" />
-      <Name>osu.Game</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj">
-      <Project>{48F4582B-7687-4621-9CBE-5C24197CB536}</Project>
-      <Name>osu.Game.Rulesets.Mania</Name>
-    </ProjectReference>
   </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
+</Project>
-</Project>

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <OutputType>Library</OutputType>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Description>smash the keys. to the beat.</Description>
@@ -15,4 +15,4 @@
   <ItemGroup Label="Project References">
     <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
-</Project>
+</Project>

osu.Game.Rulesets.Osu.Tests.Android/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="osu.Game.Rulesets.Osu.Tests.Android" android:installLocation="auto">
-	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="29" />
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" />
 	<application android:allowBackup="true" android:supportsRtl="true" android:label="osu!standard Test" />
 </manifest>

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

@@ -1,49 +1,27 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\osu.Android.props" />
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <TargetFramework>net6.0-android</TargetFramework>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <OutputType>Exe</OutputType>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>{90CAB706-39CB-4B93-9629-3218A6FF8E9B}</ProjectGuid>
-    <ProjectTypeGuids>{EFBA0AD7-5A72-4C68-AF49-83D382785DCF};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <TemplateGuid>{122416d6-6b49-4ee2-a1e8-b825f31c79fe}</TemplateGuid>
     <RootNamespace>osu.Game.Rulesets.Osu.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Osu.Tests.Android</AssemblyName>
-    <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
-    <AndroidSupportedAbis>armeabi-v7a;x86;arm64-v8a</AndroidSupportedAbis>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <AndroidLinkMode>None</AndroidLinkMode>
-    <MandroidI18n>cjk;mideast;other;rare;west</MandroidI18n>
-    <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="MainActivity.cs" />
+    <Compile Include="..\osu.Game.Rulesets.Osu.Tests\**\*.cs" Exclude="**\obj\**">
-  </ItemGroup>
-  <ItemGroup>
-    <None Include="Properties\AndroidManifest.xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="..\osu.Game.Rulesets.Osu.Tests\*.cs">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
+    <!-- TargetPath is relative to RootNamespace,
+         and DllResourceStore is relative to AssemblyName. -->
+    <EmbeddedResource Include="..\osu.Game.Rulesets.Osu.Tests\**\Resources\**\*">
+      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
+      <TargetPath>Android\%(RecursiveDir)%(Filename)%(Extension)</TargetPath>
+    </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj">
+    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj" />
-      <Project>{c92a607b-1fdd-4954-9f92-03ff547d9080}</Project>
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Name>osu.Game.Rulesets.Osu</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
-      <Project>{2a66dd92-adb1-4994-89e2-c94e04acda0d}</Project>
-      <Name>osu.Game</Name>
-    </ProjectReference>
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="System.Formats.Asn1">
+    <PackageReference Include="Moq" Version="4.17.2" />
-      <Version>5.0.0</Version>
-    </PackageReference>
   </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
 </Project>

osu.Game.Rulesets.Osu.Tests.iOS/Application.cs

@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using osu.Framework.iOS;
 using UIKit;
 
 namespace osu.Game.Rulesets.Osu.Tests.iOS
@@ -12,7 +11,7 @@ namespace osu.Game.Rulesets.Osu.Tests.iOS
     {
         public static void Main(string[] args)
         {
-            UIApplication.Main(args, typeof(GameUIApplication), typeof(AppDelegate));
+            UIApplication.Main(args, null, typeof(AppDelegate));
         }
     }
 }

osu.Game.Rulesets.Osu.Tests.iOS/Info.plist

@@ -13,7 +13,7 @@
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>MinimumOSVersion</key>
-	<string>10.0</string>
+	<string>13.4</string>
 	<key>UIDeviceFamily</key>
 	<array>
 		<integer>1</integer>

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

@@ -1,35 +1,20 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <OutputType>Exe</OutputType>
-    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
+    <TargetFramework>net6.0-ios</TargetFramework>
-    <ProjectGuid>{6653CA6F-DB06-4604-A3FD-762E25C2AF96}</ProjectGuid>
+    <SupportedOSPlatformVersion>13.4</SupportedOSPlatformVersion>
     <OutputType>Exe</OutputType>
     <RootNamespace>osu.Game.Rulesets.Osu.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Osu.Tests.iOS</AssemblyName>
   </PropertyGroup>
   <Import Project="..\osu.iOS.props" />
   <ItemGroup>
-    <None Include="Info.plist" />
-    <None Include="Entitlements.plist" />
-    <LinkDescription Include="..\osu.iOS\Linker.xml">
-      <Link>Linker.xml</Link>
-    </LinkDescription>
-    <Compile Include="Application.cs" />
-    <Compile Include="AppDelegate.cs" />
     <Compile Include="..\osu.Game.Rulesets.Osu.Tests\**\*.cs" Exclude="**\obj\**">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
   </ItemGroup>
   <ItemGroup Label="Project References">
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Project>{2A66DD92-ADB1-4994-89E2-C94E04ACDA0D}</Project>
+    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj" />
-      <Name>osu.Game</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj">
-      <Project>{C92A607B-1FDD-4954-9F92-03FF547D9080}</Project>
-      <Name>osu.Game.Rulesets.Osu</Name>
-    </ProjectReference>
   </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
+</Project>
-</Project>

osu.Game.Rulesets.Osu/Edit/Blueprints/Sliders/Components/PathControlPointVisualiser.cs

@@ -133,6 +133,8 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
             switch (e.Action)
             {
                 case NotifyCollectionChangedAction.Add:
+                    Debug.Assert(e.NewItems != null);
+
                     // If inserting in the path (not appending),
                     // update indices of existing connections after insert location
                     if (e.NewStartingIndex < Pieces.Count)
@@ -164,6 +166,8 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
                     break;
 
                 case NotifyCollectionChangedAction.Remove:
+                    Debug.Assert(e.OldItems != null);
+
                     foreach (var point in e.OldItems.Cast<PathControlPoint>())
                     {
                         foreach (var piece in Pieces.Where(p => p.ControlPoint == point).ToArray())

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

@@ -82,7 +82,7 @@ namespace osu.Game.Rulesets.Osu.Replays
 
         private class ReplayFrameComparer : IComparer<ReplayFrame>
         {
-            public int Compare(ReplayFrame f1, ReplayFrame f2)
+            public int Compare(ReplayFrame? f1, ReplayFrame? f2)
             {
                 if (f1 == null) throw new ArgumentNullException(nameof(f1));
                 if (f2 == null) throw new ArgumentNullException(nameof(f2));

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <OutputType>Library</OutputType>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Description>click the circles. to the beat.</Description>
@@ -15,4 +15,4 @@
   <ItemGroup Label="Project References">
     <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
   </ItemGroup>
-</Project>
+</Project>

osu.Game.Rulesets.Taiko.Tests.Android/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="osu.Game.Rulesets.Taiko.Tests.Android" android:installLocation="auto">
-	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="29" />
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" />
 	<application android:allowBackup="true" android:supportsRtl="true" android:label="osu!taiko Test" />
 </manifest>

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

@@ -1,49 +1,24 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\osu.Android.props" />
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <TargetFramework>net6.0-android</TargetFramework>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <OutputType>Exe</OutputType>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>{3701A0A1-8476-42C6-B5C4-D24129B4A484}</ProjectGuid>
-    <ProjectTypeGuids>{EFBA0AD7-5A72-4C68-AF49-83D382785DCF};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <TemplateGuid>{122416d6-6b49-4ee2-a1e8-b825f31c79fe}</TemplateGuid>
     <RootNamespace>osu.Game.Rulesets.Taiko.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Taiko.Tests.Android</AssemblyName>
-    <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
-    <AndroidSupportedAbis>armeabi-v7a;x86;arm64-v8a</AndroidSupportedAbis>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <AndroidLinkMode>None</AndroidLinkMode>
-    <MandroidI18n>cjk;mideast;other;rare;west</MandroidI18n>
-    <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="MainActivity.cs" />
+    <Compile Include="..\osu.Game.Rulesets.Taiko.Tests\**\*.cs" Exclude="**\obj\**">
-  </ItemGroup>
-  <ItemGroup>
-    <None Include="Properties\AndroidManifest.xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="..\osu.Game.Rulesets.Taiko.Tests\*.cs">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
+    <!-- TargetPath is relative to RootNamespace,
+         and DllResourceStore is relative to AssemblyName. -->
+    <EmbeddedResource Include="..\osu.Game.Rulesets.Taiko.Tests\**\Resources\**\*">
+      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
+      <TargetPath>Android\%(RecursiveDir)%(Filename)%(Extension)</TargetPath>
+    </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj">
+    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
-      <Project>{f167e17a-7de6-4af5-b920-a5112296c695}</Project>
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Name>osu.Game.Rulesets.Taiko</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
-      <Project>{2a66dd92-adb1-4994-89e2-c94e04acda0d}</Project>
-      <Name>osu.Game</Name>
-    </ProjectReference>
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="System.Formats.Asn1">
-      <Version>5.0.0</Version>
-    </PackageReference>
-  </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
 </Project>

osu.Game.Rulesets.Taiko.Tests.iOS/Application.cs

@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using osu.Framework.iOS;
 using UIKit;
 
 namespace osu.Game.Rulesets.Taiko.Tests.iOS
@@ -12,7 +11,7 @@ namespace osu.Game.Rulesets.Taiko.Tests.iOS
     {
         public static void Main(string[] args)
         {
-            UIApplication.Main(args, typeof(GameUIApplication), typeof(AppDelegate));
+            UIApplication.Main(args, null, typeof(AppDelegate));
         }
     }
 }

osu.Game.Rulesets.Taiko.Tests.iOS/Info.plist

@@ -13,7 +13,7 @@
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>MinimumOSVersion</key>
-	<string>10.0</string>
+	<string>13.4</string>
 	<key>UIDeviceFamily</key>
 	<array>
 		<integer>1</integer>

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

@@ -1,35 +1,19 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
-    <ProjectGuid>{7E408809-66AC-49D1-AF4D-98834F9B979A}</ProjectGuid>
     <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0-ios</TargetFramework>
+    <SupportedOSPlatformVersion>13.4</SupportedOSPlatformVersion>
     <RootNamespace>osu.Game.Rulesets.Taiko.Tests</RootNamespace>
     <AssemblyName>osu.Game.Rulesets.Taiko.Tests.iOS</AssemblyName>
   </PropertyGroup>
   <Import Project="..\osu.iOS.props" />
   <ItemGroup>
-    <None Include="Info.plist" />
-    <None Include="Entitlements.plist" />
-    <LinkDescription Include="..\osu.iOS\Linker.xml">
-      <Link>Linker.xml</Link>
-    </LinkDescription>
-    <Compile Include="Application.cs" />
-    <Compile Include="AppDelegate.cs" />
     <Compile Include="..\osu.Game.Rulesets.Taiko.Tests\**\*.cs" Exclude="**\obj\**">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
   </ItemGroup>
   <ItemGroup Label="Project References">
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Project>{2A66DD92-ADB1-4994-89E2-C94E04ACDA0D}</Project>
+    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
-      <Name>osu.Game</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj">
-      <Project>{F167E17A-7DE6-4AF5-B920-A5112296C695}</Project>
-      <Name>osu.Game.Rulesets.Taiko</Name>
-    </ProjectReference>
   </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
+</Project>
-</Project>

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

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <OutputType>Library</OutputType>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Description>bash the drum. to the beat.</Description>

osu.Game.Tests.Android/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="osu.Game.Tests.Android" android:installLocation="auto">
-	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="29" />
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" />
 	<application android:allowBackup="true" android:supportsRtl="true" android:label="osu!visual Test" />
 </manifest>

osu.Game.Tests.Android/MainActivity.cs

@@ -3,7 +3,9 @@
 
 #nullable disable
 
+using System.Reflection;
 using Android.App;
+using Android.OS;
 using osu.Framework.Android;
 
 namespace osu.Game.Tests.Android
@@ -12,5 +14,16 @@ namespace osu.Game.Tests.Android
     public class MainActivity : AndroidGameActivity
     {
         protected override Framework.Game CreateGame() => new OsuTestBrowser();
+
+        protected override void OnCreate(Bundle savedInstanceState)
+        {
+            base.OnCreate(savedInstanceState);
+
+            // See the comment in OsuGameActivity
+            Assembly.Load("osu.Game.Rulesets.Osu");
+            Assembly.Load("osu.Game.Rulesets.Taiko");
+            Assembly.Load("osu.Game.Rulesets.Catch");
+            Assembly.Load("osu.Game.Rulesets.Mania");
+        }
     }
 }

osu.Game.Tests.Android/osu.Game.Tests.Android.csproj

@@ -1,88 +1,34 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="..\osu.Android.props" />
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <TargetFramework>net6.0-android</TargetFramework>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <OutputType>Exe</OutputType>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>{5CC222DC-5716-4499-B897-DCBDDA4A5CF9}</ProjectGuid>
-    <ProjectTypeGuids>{EFBA0AD7-5A72-4C68-AF49-83D382785DCF};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <TemplateGuid>{122416d6-6b49-4ee2-a1e8-b825f31c79fe}</TemplateGuid>
     <RootNamespace>osu.Game.Tests</RootNamespace>
     <AssemblyName>osu.Game.Tests.Android</AssemblyName>
-    <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
-    <AndroidSupportedAbis>armeabi-v7a;x86;arm64-v8a</AndroidSupportedAbis>
   </PropertyGroup>
-  <ItemGroup>
-    <Compile Include="MainActivity.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <None Include="Properties\AndroidManifest.xml" />
-  </ItemGroup>
   <PropertyGroup>
     <NoWarn>$(NoWarn);CA2007</NoWarn>
   </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <AndroidLinkMode>None</AndroidLinkMode>
-    <MandroidI18n>cjk;mideast;other;rare;west</MandroidI18n>
-    <EmbedAssembliesIntoApk>true</EmbedAssembliesIntoApk>
-  </PropertyGroup>
   <ItemGroup>
-    <Compile Include="..\osu.Game.Tests\**\Beatmaps\**\*.cs">
+    <Compile Include="..\osu.Game.Tests\**\*.cs" Exclude="**\obj\**">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
-    <Compile Remove="..\osu.Game.Tests\Beatmaps\Formats\OsuJsonDecoderTest.cs" />
+    <!-- TargetPath is relative to RootNamespace,
-    <Compile Include="..\osu.Game.Tests\**\Chat\**\*.cs">
+         and DllResourceStore is relative to AssemblyName. -->
+    <EmbeddedResource Include="..\osu.Game.Tests\**\Resources\**\*">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
-    </Compile>
+      <TargetPath>Android\%(RecursiveDir)%(Filename)%(Extension)</TargetPath>
-    <Compile Include="..\osu.Game.Tests\**\NonVisual\**\*.cs">
+    </EmbeddedResource>
-      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
-    </Compile>
-    <Compile Include="..\osu.Game.Tests\**\Scores\**\*.cs">
-      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
-    </Compile>
-    <Compile Include="..\osu.Game.Tests\**\ScrollAlgorithms\**\*.cs">
-      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
-    </Compile>
-    <Compile Include="..\osu.Game.Tests\**\Visual\**\*.cs">
-      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
-    </Compile>
-    <Compile Include="..\osu.Game.Tests\**\Resources\**\*.cs">
-      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
-    </Compile>
-    <Compile Include="..\osu.Game.Tests\*.cs">
-      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
-    </Compile>
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj">
+    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj" />
-      <Project>{58f6c80c-1253-4a0e-a465-b8c85ebeadf3}</Project>
+    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj" />
-      <Name>osu.Game.Rulesets.Catch</Name>
+    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj" />
-    </ProjectReference>
+    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
-    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj">
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Project>{48f4582b-7687-4621-9cbe-5c24197cb536}</Project>
-      <Name>osu.Game.Rulesets.Mania</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj">
-      <Project>{c92a607b-1fdd-4954-9f92-03ff547d9080}</Project>
-      <Name>osu.Game.Rulesets.Osu</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj">
-      <Project>{f167e17a-7de6-4af5-b920-a5112296c695}</Project>
-      <Name>osu.Game.Rulesets.Taiko</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
-      <Project>{2a66dd92-adb1-4994-89e2-c94e04acda0d}</Project>
-      <Name>osu.Game</Name>
-    </ProjectReference>
   </ItemGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="DeepEqual" Version="2.0.0" />
     <PackageReference Include="Moq" Version="4.17.2" />
-    <PackageReference Include="System.Formats.Asn1">
-      <Version>5.0.0</Version>
-    </PackageReference>
   </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
 </Project>

osu.Game.Tests.iOS/Application.cs

@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using osu.Framework.iOS;
 using UIKit;
 
 namespace osu.Game.Tests.iOS
@@ -12,7 +11,7 @@ namespace osu.Game.Tests.iOS
     {
         public static void Main(string[] args)
         {
-            UIApplication.Main(args, typeof(GameUIApplication), typeof(AppDelegate));
+            UIApplication.Main(args, null, typeof(AppDelegate));
         }
     }
 }

osu.Game.Tests.iOS/Info.plist

@@ -13,7 +13,7 @@
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>MinimumOSVersion</key>
-	<string>10.0</string>
+	<string>13.4</string>
 	<key>UIDeviceFamily</key>
 	<array>
 		<integer>1</integer>

osu.Game.Tests.iOS/osu.Game.Tests.iOS.csproj

@@ -1,54 +1,26 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
     <OutputType>Exe</OutputType>
-    <ProjectGuid>{65FF8E19-6934-469B-B690-23C6D6E56A17}</ProjectGuid>
+    <TargetFramework>net6.0-ios</TargetFramework>
+    <SupportedOSPlatformVersion>13.4</SupportedOSPlatformVersion>
     <RootNamespace>osu.Game.Tests</RootNamespace>
     <AssemblyName>osu.Game.Tests.iOS</AssemblyName>
   </PropertyGroup>
   <Import Project="..\osu.iOS.props" />
   <ItemGroup>
-    <None Include="Info.plist" />
-    <None Include="Entitlements.plist" />
-    <LinkDescription Include="..\osu.iOS\Linker.xml">
-      <Link>Linker.xml</Link>
-    </LinkDescription>
-    <Compile Include="Application.cs" />
-    <Compile Include="AppDelegate.cs" />
     <Compile Include="..\osu.Game.Tests\**\*.cs" Exclude="**\obj\**">
       <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
     </Compile>
   </ItemGroup>
-  <PropertyGroup>
-    <NoWarn>$(NoWarn);CA2007</NoWarn>
-  </PropertyGroup>
   <ItemGroup Label="Project References">
-    <ProjectReference Include="..\osu.Game\osu.Game.csproj">
+    <ProjectReference Include="..\osu.Game\osu.Game.csproj" />
-      <Project>{2A66DD92-ADB1-4994-89E2-C94E04ACDA0D}</Project>
+    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj" />
-      <Name>osu.Game</Name>
+    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj" />
-    </ProjectReference>
+    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj" />
-    <ProjectReference Include="..\osu.Game.Rulesets.Osu\osu.Game.Rulesets.Osu.csproj">
+    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
-      <Project>{C92A607B-1FDD-4954-9F92-03FF547D9080}</Project>
-      <Name>osu.Game.Rulesets.Osu</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Catch\osu.Game.Rulesets.Catch.csproj">
-      <Project>{58F6C80C-1253-4A0E-A465-B8C85EBEADF3}</Project>
-      <Name>osu.Game.Rulesets.Catch</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Mania\osu.Game.Rulesets.Mania.csproj">
-      <Project>{48F4582B-7687-4621-9CBE-5C24197CB536}</Project>
-      <Name>osu.Game.Rulesets.Mania</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj">
-      <Project>{F167E17A-7DE6-4AF5-B920-A5112296C695}</Project>
-      <Name>osu.Game.Rulesets.Taiko</Name>
-    </ProjectReference>
   </ItemGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="DeepEqual" Version="2.0.0" />
     <PackageReference Include="Moq" Version="4.17.2" />
   </ItemGroup>
-  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
 </Project>

osu.Game.Tests/Chat/MessageFormatterTests.cs

@@ -26,6 +26,16 @@ namespace osu.Game.Tests.Chat
             MessageFormatter.WebsiteRootUrl = originalWebsiteRootUrl;
         }
 
+        [Test]
+        public void TestUnsupportedProtocolLink()
+        {
+            Message result = MessageFormatter.FormatMessage(new Message { Content = "This is a gopher://really-old-protocol we don't support." });
+
+            Assert.AreEqual(result.Content, result.DisplayContent);
+            Assert.AreEqual(1, result.Links.Count);
+            Assert.AreEqual("gopher://really-old-protocol", result.Links[0].Url);
+        }
+
         [Test]
         public void TestBareLink()
         {

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

@@ -189,7 +189,7 @@ namespace osu.Game.Tests.Visual.Online
                     if (request is not CommentDeleteRequest req)
                         return false;
 
-                    req.TriggerFailure(new Exception());
+                    req.TriggerFailure(new InvalidOperationException());
                     delete = true;
                     return false;
                 };

osu.Game.Tests/Visual/SongSelect/TestSceneUpdateBeatmapSetButton.cs

@@ -136,7 +136,7 @@ namespace osu.Game.Tests.Visual.SongSelect
 
                     if (testRequest.Progress >= 0.5f)
                     {
-                        testRequest.TriggerFailure(new Exception());
+                        testRequest.TriggerFailure(new InvalidOperationException());
                         return true;
                     }
                 }

osu.Game.Tournament/IPC/FileBasedIPC.cs

@@ -245,8 +245,10 @@ namespace osu.Game.Tournament.IPC
             {
                 string stableInstallPath;
 
+#pragma warning disable CA1416
                 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
 
                 if (ipcFileExistsInDirectory(stableInstallPath))
                     return stableInstallPath;

osu.Game.Tournament/SaveChangesOverlay.cs

@@ -70,7 +70,7 @@ namespace osu.Game.Tournament
 
         private async Task checkForChanges()
         {
-            string serialisedLadder = await Task.Run(() => tournamentGame.GetSerialisedLadder());
+            string serialisedLadder = await Task.Run(() => tournamentGame.GetSerialisedLadder()).ConfigureAwait(false);
 
             // If a save hasn't been triggered by the user yet, populate the initial value
             lastSerialisedLadder ??= serialisedLadder;

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

@@ -5,7 +5,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -54,8 +53,6 @@ namespace osu.Game.Tournament.Screens.Editors
                 });
             }
 
-            Debug.Assert(countries != null);
-
             foreach (var c in countries)
                 Storage.Add(c);
         }

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

@@ -4,6 +4,7 @@
 #nullable disable
 
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -102,10 +103,14 @@ namespace osu.Game.Tournament.Screens.Editors
                 switch (args.Action)
                 {
                     case NotifyCollectionChangedAction.Add:
+                        Debug.Assert(args.NewItems != null);
+
                         args.NewItems.Cast<TModel>().ForEach(i => flow.Add(CreateDrawable(i)));
                         break;
 
                     case NotifyCollectionChangedAction.Remove:
+                        Debug.Assert(args.OldItems != null);
+
                         args.OldItems.Cast<TModel>().ForEach(i => flow.RemoveAll(d => d.Model == i, true));
                         break;
                 }

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

@@ -5,6 +5,7 @@
 
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -20,8 +21,6 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
 {
     public partial class LadderEditorSettings : PlayerSettingsGroup
     {
-        private const int padding = 10;
-
         private SettingsDropdown<TournamentRound> roundDropdown;
         private PlayerCheckbox losersCheckbox;
         private DateTextBox dateTimeBox;
@@ -103,10 +102,14 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
                     switch (args.Action)
                     {
                         case NotifyCollectionChangedAction.Add:
+                            Debug.Assert(args.NewItems != null);
+
                             args.NewItems.Cast<TournamentRound>().ForEach(add);
                             break;
 
                         case NotifyCollectionChangedAction.Remove:
+                            Debug.Assert(args.OldItems != null);
+
                             args.OldItems.Cast<TournamentRound>().ForEach(i => Control.RemoveDropdownItem(i));
                             break;
                     }

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

@@ -5,6 +5,7 @@
 
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions.IEnumerableExtensions;
@@ -25,10 +26,14 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
                 switch (args.Action)
                 {
                     case NotifyCollectionChangedAction.Add:
+                        Debug.Assert(args.NewItems != null);
+
                         args.NewItems.Cast<TournamentTeam>().ForEach(add);
                         break;
 
                     case NotifyCollectionChangedAction.Remove:
+                        Debug.Assert(args.OldItems != null);
+
                         args.OldItems.Cast<TournamentTeam>().ForEach(i => Control.RemoveDropdownItem(i));
                         break;
                 }

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

@@ -4,6 +4,7 @@
 #nullable disable
 
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Caching;
@@ -81,11 +82,15 @@ namespace osu.Game.Tournament.Screens.Ladder
                 switch (args.Action)
                 {
                     case NotifyCollectionChangedAction.Add:
+                        Debug.Assert(args.NewItems != null);
+
                         foreach (var p in args.NewItems.Cast<TournamentMatch>())
                             addMatch(p);
                         break;
 
                     case NotifyCollectionChangedAction.Remove:
+                        Debug.Assert(args.OldItems != null);
+
                         foreach (var p in args.OldItems.Cast<TournamentMatch>())
                         {
                             foreach (var d in MatchesContainer.Where(d => d.Match == p))
@@ -153,7 +158,7 @@ namespace osu.Game.Tournament.Screens.Ladder
 
             foreach (var round in LadderInfo.Rounds)
             {
-                var topMatch = MatchesContainer.Where(p => !p.Match.Losers.Value && p.Match.Round.Value == round).OrderBy(p => p.Y).FirstOrDefault();
+                var topMatch = MatchesContainer.Where(p => !p.Match.Losers.Value && p.Match.Round.Value == round).MinBy(p => p.Y);
 
                 if (topMatch == null) continue;
 
@@ -167,7 +172,7 @@ namespace osu.Game.Tournament.Screens.Ladder
 
             foreach (var round in LadderInfo.Rounds)
             {
-                var topMatch = MatchesContainer.Where(p => p.Match.Losers.Value && p.Match.Round.Value == round).OrderBy(p => p.Y).FirstOrDefault();
+                var topMatch = MatchesContainer.Where(p => p.Match.Losers.Value && p.Match.Round.Value == round).MinBy(p => p.Y);
 
                 if (topMatch == null) continue;
 

osu.Game.Tournament/osu.Game.Tournament.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup Label="Project">
-    <TargetFramework>netstandard2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <OutputType>Library</OutputType>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Description>tools for tournaments.</Description>
@@ -11,4 +11,4 @@
   <ItemGroup Label="Package References">
     <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0" />
   </ItemGroup>
-</Project>
+</Project>

osu.Game/Audio/SampleInfo.cs

@@ -35,7 +35,7 @@ namespace osu.Game.Audio
         public bool Equals(SampleInfo? other)
             => other != null && sampleNames.SequenceEqual(other.sampleNames);
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
             => obj is SampleInfo other && Equals(other);
     }
 }

osu.Game/Beatmaps/BeatmapImporter.cs

@@ -44,7 +44,7 @@ namespace osu.Game.Beatmaps
 
         public override async Task<Live<BeatmapSetInfo>?> ImportAsUpdate(ProgressNotification notification, ImportTask importTask, BeatmapSetInfo original)
         {
-            var imported = await Import(notification, new[] { importTask });
+            var imported = await Import(notification, new[] { importTask }).ConfigureAwait(true);
 
             if (!imported.Any())
                 return null;

osu.Game/Beatmaps/BeatmapUpdaterMetadataLookup.cs

@@ -178,7 +178,7 @@ namespace osu.Game.Beatmaps
             {
                 try
                 {
-                    await cacheDownloadRequest.PerformAsync();
+                    await cacheDownloadRequest.PerformAsync().ConfigureAwait(false);
                 }
                 catch
                 {

osu.Game/Beatmaps/ControlPoints/ControlPoint.cs

@@ -16,7 +16,7 @@ namespace osu.Game.Beatmaps.ControlPoints
 
         public void AttachGroup(ControlPointGroup pointGroup) => Time = pointGroup.Time;
 
-        public int CompareTo(ControlPoint other) => Time.CompareTo(other.Time);
+        public int CompareTo(ControlPoint? other) => Time.CompareTo(other?.Time);
 
         public virtual Color4 GetRepresentingColour(OsuColour colours) => colours.Yellow;
 
@@ -32,7 +32,7 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// </summary>
         public ControlPoint DeepClone()
         {
-            var copy = (ControlPoint)Activator.CreateInstance(GetType());
+            var copy = (ControlPoint)Activator.CreateInstance(GetType())!;
 
             copy.CopyFrom(this);
 

osu.Game/Beatmaps/ControlPoints/ControlPointGroup.cs

@@ -26,7 +26,7 @@ namespace osu.Game.Beatmaps.ControlPoints
             Time = time;
         }
 
-        public int CompareTo(ControlPointGroup other) => Time.CompareTo(other.Time);
+        public int CompareTo(ControlPointGroup? other) => Time.CompareTo(other?.Time);
 
         public void Add(ControlPoint point)
         {

osu.Game/Beatmaps/ControlPoints/ControlPointInfo.cs

@@ -70,14 +70,14 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// </summary>
         [JsonIgnore]
         public double BPMMaximum =>
-            60000 / (TimingPoints.OrderBy(c => c.BeatLength).FirstOrDefault() ?? TimingControlPoint.DEFAULT).BeatLength;
+            60000 / (TimingPoints.MinBy(c => c.BeatLength) ?? TimingControlPoint.DEFAULT).BeatLength;
 
         /// <summary>
         /// Finds the minimum BPM represented by any timing control point.
         /// </summary>
         [JsonIgnore]
         public double BPMMinimum =>
-            60000 / (TimingPoints.OrderByDescending(c => c.BeatLength).FirstOrDefault() ?? TimingControlPoint.DEFAULT).BeatLength;
+            60000 / (TimingPoints.MaxBy(c => c.BeatLength) ?? TimingControlPoint.DEFAULT).BeatLength;
 
         /// <summary>
         /// Remove all <see cref="ControlPointGroup"/>s and return to a pristine state.
@@ -300,7 +300,7 @@ namespace osu.Game.Beatmaps.ControlPoints
 
         public ControlPointInfo DeepClone()
         {
-            var controlPointInfo = (ControlPointInfo)Activator.CreateInstance(GetType());
+            var controlPointInfo = (ControlPointInfo)Activator.CreateInstance(GetType())!;
 
             foreach (var point in AllControlPoints)
                 controlPointInfo.Add(point.Time, point.DeepClone());

osu.Game/Beatmaps/DifficultyRecommender.cs

@@ -51,11 +51,11 @@ namespace osu.Game.Beatmaps
                 if (!recommendedDifficultyMapping.TryGetValue(r, out double recommendation))
                     continue;
 
-                BeatmapInfo beatmapInfo = beatmaps.Where(b => b.Ruleset.ShortName.Equals(r)).OrderBy(b =>
+                BeatmapInfo beatmapInfo = beatmaps.Where(b => b.Ruleset.ShortName.Equals(r, StringComparison.Ordinal)).MinBy(b =>
                 {
                     double difference = b.StarRating - recommendation;
                     return difference >= 0 ? difference * 2 : difference * -1; // prefer easier over harder
-                }).FirstOrDefault();
+                });
 
                 if (beatmapInfo != null)
                     return beatmapInfo;
@@ -90,7 +90,7 @@ namespace osu.Game.Beatmaps
                 return recommendedDifficultyMapping
                        .OrderByDescending(pair => pair.Value)
                        .Select(pair => pair.Key)
-                       .Where(r => !r.Equals(ruleset.Value.ShortName))
+                       .Where(r => !r.Equals(ruleset.Value.ShortName, StringComparison.Ordinal))
                        .Prepend(ruleset.Value.ShortName);
             }
         }

osu.Game/Configuration/SettingSourceAttribute.cs

@@ -91,15 +91,15 @@ namespace osu.Game.Configuration
             OrderPosition = orderPosition;
         }
 
-        public int CompareTo(SettingSourceAttribute other)
+        public int CompareTo(SettingSourceAttribute? other)
         {
-            if (OrderPosition == other.OrderPosition)
+            if (OrderPosition == other?.OrderPosition)
                 return 0;
 
             // unordered items come last (are greater than any ordered items).
             if (OrderPosition == null)
                 return 1;
-            if (other.OrderPosition == null)
+            if (other?.OrderPosition == null)
                 return -1;
 
             // ordered items are sorted by the order value.
@@ -113,7 +113,7 @@ namespace osu.Game.Configuration
         {
             foreach (var (attr, property) in obj.GetOrderedSettingsSourceProperties())
             {
-                object value = property.GetValue(obj);
+                object value = property.GetValue(obj)!;
 
                 if (attr.SettingControlType != null)
                 {
@@ -121,7 +121,7 @@ namespace osu.Game.Configuration
                     if (controlType.EnumerateBaseTypes().All(t => !t.IsGenericType || t.GetGenericTypeDefinition() != typeof(SettingsItem<>)))
                         throw new InvalidOperationException($"{nameof(SettingSourceAttribute)} had an unsupported custom control type ({controlType.ReadableName()})");
 
-                    var control = (Drawable)Activator.CreateInstance(controlType);
+                    var control = (Drawable)Activator.CreateInstance(controlType)!;
                     controlType.GetProperty(nameof(SettingsItem<object>.SettingSourceObject))?.SetValue(control, obj);
                     controlType.GetProperty(nameof(SettingsItem<object>.LabelText))?.SetValue(control, attr.Label);
                     controlType.GetProperty(nameof(SettingsItem<object>.TooltipText))?.SetValue(control, attr.Description);
@@ -188,7 +188,7 @@ namespace osu.Game.Configuration
 
                     case IBindable bindable:
                         var dropdownType = typeof(ModSettingsEnumDropdown<>).MakeGenericType(bindable.GetType().GetGenericArguments()[0]);
-                        var dropdown = (Drawable)Activator.CreateInstance(dropdownType);
+                        var dropdown = (Drawable)Activator.CreateInstance(dropdownType)!;
 
                         dropdownType.GetProperty(nameof(SettingsDropdown<object>.LabelText))?.SetValue(dropdown, attr.Label);
                         dropdownType.GetProperty(nameof(SettingsDropdown<object>.TooltipText))?.SetValue(dropdown, attr.Description);
@@ -231,7 +231,7 @@ namespace osu.Game.Configuration
                     // An unknown (e.g. enum) generic type.
                     var valueMethod = u.GetType().GetProperty(nameof(IBindable<int>.Value));
                     Debug.Assert(valueMethod != null);
-                    return valueMethod.GetValue(u);
+                    return valueMethod.GetValue(u)!;
 
                 default:
                     // fall back for non-bindable cases.

osu.Game/Database/LegacyImportManager.cs

@@ -79,16 +79,16 @@ namespace osu.Game.Database
             switch (content)
             {
                 case StableContent.Beatmaps:
-                    return await new LegacyBeatmapImporter(beatmaps).GetAvailableCount(stableStorage);
+                    return await new LegacyBeatmapImporter(beatmaps).GetAvailableCount(stableStorage).ConfigureAwait(false);
 
                 case StableContent.Skins:
-                    return await new LegacySkinImporter(skins).GetAvailableCount(stableStorage);
+                    return await new LegacySkinImporter(skins).GetAvailableCount(stableStorage).ConfigureAwait(false);
 
                 case StableContent.Collections:
-                    return await new LegacyCollectionImporter(realmAccess).GetAvailableCount(stableStorage);
+                    return await new LegacyCollectionImporter(realmAccess).GetAvailableCount(stableStorage).ConfigureAwait(false);
 
                 case StableContent.Scores:
-                    return await new LegacyScoreImporter(scores).GetAvailableCount(stableStorage);
+                    return await new LegacyScoreImporter(scores).GetAvailableCount(stableStorage).ConfigureAwait(false);
 
                 default:
                     throw new ArgumentException($"Only one {nameof(StableContent)} flag should be specified.");

osu.Game/Database/Live.cs

@@ -61,6 +61,6 @@ namespace osu.Game.Database
 
         public override int GetHashCode() => HashCode.Combine(ID);
 
-        public override string ToString() => PerformRead(i => i.ToString());
+        public override string? ToString() => PerformRead(i => i.ToString());
     }
 }

osu.Game/Database/ModelDownloader.cs

@@ -71,9 +71,9 @@ namespace osu.Game.Database
                     bool importSuccessful;
 
                     if (originalModel != null)
-                        importSuccessful = (await importer.ImportAsUpdate(notification, new ImportTask(filename), originalModel)) != null;
+                        importSuccessful = (await importer.ImportAsUpdate(notification, new ImportTask(filename), originalModel).ConfigureAwait(false)) != null;
                     else
-                        importSuccessful = (await importer.Import(notification, new[] { new ImportTask(filename) })).Any();
+                        importSuccessful = (await importer.Import(notification, new[] { new ImportTask(filename) }).ConfigureAwait(false)).Any();
 
                     // for now a failed import will be marked as a failed download for simplicity.
                     if (!importSuccessful)

osu.Game/Database/RealmAccess.cs

@@ -481,7 +481,7 @@ namespace osu.Game.Database
                 // server, which we don't use. May want to report upstream or revisit in the future.
                 using (var realm = getRealmInstance())
                     // ReSharper disable once AccessToDisposedClosure (WriteAsync should be marked as [InstantHandle]).
-                    await realm.WriteAsync(() => action(realm));
+                    await realm.WriteAsync(() => action(realm)).ConfigureAwait(false);
 
                 pendingAsyncWrites.Signal();
             });
@@ -558,7 +558,7 @@ namespace osu.Game.Database
 
                 return new InvokeOnDisposal(() => model.PropertyChanged -= onPropertyChanged);
 
-                void onPropertyChanged(object sender, PropertyChangedEventArgs args)
+                void onPropertyChanged(object? sender, PropertyChangedEventArgs args)
                 {
                     if (args.PropertyName == propertyName)
                         onChanged(propLookupCompiled(model));

osu.Game/Extensions/DrawableExtensions.cs

@@ -66,10 +66,10 @@ namespace osu.Game.Extensions
 
                 foreach (var (_, property) in component.GetSettingsSourceProperties())
                 {
-                    if (!info.Settings.TryGetValue(property.Name.ToSnakeCase(), out object settingValue))
+                    if (!info.Settings.TryGetValue(property.Name.ToSnakeCase(), out object? settingValue))
                         continue;
 
-                    skinnable.CopyAdjustedSetting((IBindable)property.GetValue(component), settingValue);
+                    skinnable.CopyAdjustedSetting(((IBindable)property.GetValue(component)!), settingValue);
                 }
             }
 

osu.Game/Extensions/TaskExtensions.cs

@@ -37,7 +37,7 @@ namespace osu.Game.Extensions
 
                 if (cancellationToken.IsCancellationRequested)
                 {
-                    tcs.SetCanceled();
+                    tcs.SetCanceled(cancellationToken);
                 }
                 else
                 {

osu.Game/Graphics/UserInterface/OsuTextBox.cs

@@ -277,7 +277,7 @@ namespace osu.Game.Graphics.UserInterface
         {
             var samples = sampleMap[feedbackSampleType];
 
-            if (samples == null || samples.Length == 0)
+            if (samples.Length == 0)
                 return null;
 
             return samples[RNG.Next(0, samples.Length)]?.GetChannel();

osu.Game/IO/Serialization/Converters/TypedListConverter.cs

@@ -63,7 +63,7 @@ namespace osu.Game.IO.Serialization.Converters
                     throw new JsonException("Expected $type token.");
 
                 string typeName = lookupTable[(int)tok["$type"]];
-                var instance = (T)Activator.CreateInstance(Type.GetType(typeName).AsNonNull());
+                var instance = (T)Activator.CreateInstance(Type.GetType(typeName).AsNonNull())!;
                 serializer.Populate(itemReader, instance);
 
                 list.Add(instance);

osu.Game/Models/RealmUser.cs

@@ -27,7 +27,7 @@ namespace osu.Game.Models
 
         public bool IsBot => false;
 
-        public bool Equals(RealmUser other)
+        public bool Equals(RealmUser? other)
         {
             if (ReferenceEquals(null, other)) return false;
             if (ReferenceEquals(this, other)) return true;

osu.Game/Online/API/APIMod.cs

@@ -39,7 +39,7 @@ namespace osu.Game.Online.API
 
             foreach (var (_, property) in mod.GetSettingsSourceProperties())
             {
-                var bindable = (IBindable)property.GetValue(mod);
+                var bindable = (IBindable)property.GetValue(mod)!;
 
                 if (!bindable.IsDefault)
                     Settings.Add(property.Name.ToSnakeCase(), bindable.GetUnderlyingSettingValue());
@@ -60,16 +60,16 @@ namespace osu.Game.Online.API
             {
                 foreach (var (_, property) in resultMod.GetSettingsSourceProperties())
                 {
-                    if (!Settings.TryGetValue(property.Name.ToSnakeCase(), out object settingValue))
+                    if (!Settings.TryGetValue(property.Name.ToSnakeCase(), out object? settingValue))
                         continue;
 
                     try
                     {
-                        resultMod.CopyAdjustedSetting((IBindable)property.GetValue(resultMod), settingValue);
+                        resultMod.CopyAdjustedSetting((IBindable)property.GetValue(resultMod)!, settingValue);
                     }
                     catch (Exception ex)
                     {
-                        Logger.Log($"Failed to copy mod setting value '{settingValue ?? "null"}' to \"{property.Name}\": {ex.Message}");
+                        Logger.Log($"Failed to copy mod setting value '{settingValue}' to \"{property.Name}\": {ex.Message}");
                     }
                 }
             }
@@ -79,7 +79,7 @@ namespace osu.Game.Online.API
 
         public bool ShouldSerializeSettings() => Settings.Count > 0;
 
-        public bool Equals(APIMod other)
+        public bool Equals(APIMod? other)
         {
             if (ReferenceEquals(null, other)) return false;
             if (ReferenceEquals(this, other)) return true;

osu.Game/Online/API/Requests/Responses/APIBeatmap.cs

@@ -143,7 +143,7 @@ namespace osu.Game.Online.API.Requests.Responses
 
             public bool Equals(IRulesetInfo? other) => other is APIRuleset r && this.MatchesOnlineID(r);
 
-            public int CompareTo(IRulesetInfo other)
+            public int CompareTo(IRulesetInfo? other)
             {
                 if (!(other is APIRuleset ruleset))
                     throw new ArgumentException($@"Object is not of type {nameof(APIRuleset)}.", nameof(other));

osu.Game/Online/Chat/MessageFormatter.cs

@@ -71,7 +71,7 @@ namespace osu.Game.Online.Chat
             {
                 int index = m.Index - captureOffset;
 
-                string? displayText = string.Format(display,
+                string displayText = string.Format(display,
                     m.Groups[0],
                     m.Groups["text"].Value,
                     m.Groups["url"].Value).Trim();
@@ -109,7 +109,7 @@ namespace osu.Game.Online.Chat
             foreach (Match m in regex.Matches(result.Text, startIndex))
             {
                 int index = m.Index;
-                string? linkText = m.Groups["link"].Value;
+                string linkText = m.Groups["link"].Value;
                 int indexLength = linkText.Length;
 
                 var details = GetLinkDetails(linkText);
@@ -125,7 +125,7 @@ namespace osu.Game.Online.Chat
 
         public static LinkDetails GetLinkDetails(string url)
         {
-            string[]? args = url.Split('/', StringSplitOptions.RemoveEmptyEntries);
+            string[] args = url.Split('/', StringSplitOptions.RemoveEmptyEntries);
             args[0] = args[0].TrimEnd(':');
 
             switch (args[0])
@@ -362,6 +362,6 @@ namespace osu.Game.Online.Chat
 
         public bool Overlaps(Link otherLink) => Index < otherLink.Index + otherLink.Length && otherLink.Index < Index + Length;
 
-        public int CompareTo(Link otherLink) => Index > otherLink.Index ? 1 : -1;
+        public int CompareTo(Link? otherLink) => Index > otherLink?.Index ? 1 : -1;
     }
 }

osu.Game/Online/Chat/MessageNotifier.cs

@@ -5,6 +5,7 @@
 
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using System.Text.RegularExpressions;
 using osu.Framework.Allocation;
@@ -61,12 +62,16 @@ namespace osu.Game.Online.Chat
             switch (e.Action)
             {
                 case NotifyCollectionChangedAction.Add:
+                    Debug.Assert(e.NewItems != null);
+
                     foreach (var channel in e.NewItems.Cast<Channel>())
                         channel.NewMessagesArrived += checkNewMessages;
 
                     break;
 
                 case NotifyCollectionChangedAction.Remove:
+                    Debug.Assert(e.OldItems != null);
+
                     foreach (var channel in e.OldItems.Cast<Channel>())
                         channel.NewMessagesArrived -= checkNewMessages;
 

osu.Game/Online/HubClientConnector.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Net;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.SignalR.Client;
@@ -59,17 +60,21 @@ namespace osu.Game.Online
             var builder = new HubConnectionBuilder()
                 .WithUrl(endpoint, options =>
                 {
-                    // Use HttpClient.DefaultProxy once on net6 everywhere.
+                    // Configuring proxies is not supported on iOS, see https://github.com/xamarin/xamarin-macios/issues/14632.
-                    // The credential setter can also be removed at this point.
+                    if (RuntimeInfo.OS != RuntimeInfo.Platform.iOS)
-                    options.Proxy = WebRequest.DefaultWebProxy;
+                    {
-                    if (options.Proxy != null)
+                        // Use HttpClient.DefaultProxy once on net6 everywhere.
-                        options.Proxy.Credentials = CredentialCache.DefaultCredentials;
+                        // The credential setter can also be removed at this point.
+                        options.Proxy = WebRequest.DefaultWebProxy;
+                        if (options.Proxy != null)
+                            options.Proxy.Credentials = CredentialCache.DefaultCredentials;
+                    }
 
                     options.Headers.Add("Authorization", $"Bearer {api.AccessToken}");
                     options.Headers.Add("OsuVersionHash", versionHash);
                 });
 
-            if (RuntimeInfo.SupportsJIT && preferMessagePack)
+            if (RuntimeFeature.IsDynamicCodeCompiled && preferMessagePack)
             {
                 builder.AddMessagePackProtocol(options =>
                 {

osu.Game/Online/Metadata/OnlineMetadataClient.cs

@@ -68,7 +68,7 @@ namespace osu.Game.Online.Metadata
                         while (true)
                         {
                             Logger.Log($"Requesting catch-up from {lastQueueId.Value}");
-                            var catchUpChanges = await GetChangesSince(lastQueueId.Value);
+                            var catchUpChanges = await GetChangesSince(lastQueueId.Value).ConfigureAwait(true);
 
                             lastQueueId.Value = catchUpChanges.LastProcessedQueueID;
 
@@ -78,7 +78,7 @@ namespace osu.Game.Online.Metadata
                                 break;
                             }
 
-                            await ProcessChanges(catchUpChanges.BeatmapSetIDs);
+                            await ProcessChanges(catchUpChanges.BeatmapSetIDs).ConfigureAwait(true);
                         }
                     }
                     catch (Exception e)
@@ -101,7 +101,7 @@ namespace osu.Game.Online.Metadata
             if (!catchingUp)
                 lastQueueId.Value = updates.LastProcessedQueueID;
 
-            await ProcessChanges(updates.BeatmapSetIDs);
+            await ProcessChanges(updates.BeatmapSetIDs).ConfigureAwait(false);
         }
 
         public override Task<BeatmapUpdates> GetChangesSince(int queueId)

osu.Game/Online/Multiplayer/MultiplayerClient.cs

@@ -822,7 +822,7 @@ namespace osu.Game.Online.Multiplayer
             {
                 if (cancellationToken.IsCancellationRequested)
                 {
-                    tcs.SetCanceled();
+                    tcs.SetCanceled(cancellationToken);
                     return;
                 }
 

osu.Game/Online/Multiplayer/MultiplayerRoomUser.cs

@@ -54,10 +54,10 @@ namespace osu.Game.Online.Multiplayer
             return UserID == other.UserID;
         }
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             if (ReferenceEquals(this, obj)) return true;
-            if (obj.GetType() != GetType()) return false;
+            if (obj?.GetType() != GetType()) return false;
 
             return Equals((MultiplayerRoomUser)obj);
         }

osu.Game/Online/Multiplayer/OnlineMultiplayerClient.cs

@@ -80,7 +80,7 @@ namespace osu.Game.Online.Multiplayer
 
             try
             {
-                return await connection.InvokeAsync<MultiplayerRoom>(nameof(IMultiplayerServer.JoinRoomWithPassword), roomId, password ?? string.Empty);
+                return await connection.InvokeAsync<MultiplayerRoom>(nameof(IMultiplayerServer.JoinRoomWithPassword), roomId, password ?? string.Empty).ConfigureAwait(false);
             }
             catch (HubException exception)
             {
@@ -88,8 +88,8 @@ namespace osu.Game.Online.Multiplayer
                 {
                     Debug.Assert(connector != null);
 
-                    await connector.Reconnect();
+                    await connector.Reconnect().ConfigureAwait(false);
-                    return await JoinRoom(roomId, password);
+                    return await JoinRoom(roomId, password).ConfigureAwait(false);
                 }
 
                 throw;

osu.Game/Online/Notifications/NotificationsClientConnector.cs

@@ -27,7 +27,7 @@ namespace osu.Game.Online.Notifications
 
         protected sealed override async Task<PersistentEndpointClient> BuildConnectionAsync(CancellationToken cancellationToken)
         {
-            var client = await BuildNotificationClientAsync(cancellationToken);
+            var client = await BuildNotificationClientAsync(cancellationToken).ConfigureAwait(false);
 
             client.ChannelJoined = c => ChannelJoined?.Invoke(c);
             client.ChannelParted = c => ChannelParted?.Invoke(c);

osu.Game/Online/Notifications/WebSocket/WebSocketNotificationsClient.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Concurrent;
 using System.Diagnostics;
+using System.Net;
 using System.Net.WebSockets;
 using System.Text;
 using System.Threading;
@@ -36,11 +37,11 @@ namespace osu.Game.Online.Notifications.WebSocket
         public override async Task ConnectAsync(CancellationToken cancellationToken)
         {
             await socket.ConnectAsync(new Uri(endpoint), cancellationToken).ConfigureAwait(false);
-            await sendMessage(new StartChatRequest(), CancellationToken.None);
+            await sendMessage(new StartChatRequest(), CancellationToken.None).ConfigureAwait(false);
 
             runReadLoop(cancellationToken);
 
-            await base.ConnectAsync(cancellationToken);
+            await base.ConnectAsync(cancellationToken).ConfigureAwait(false);
         }
 
         private void runReadLoop(CancellationToken cancellationToken) => Task.Run(async () =>
@@ -52,7 +53,7 @@ namespace osu.Game.Online.Notifications.WebSocket
             {
                 try
                 {
-                    WebSocketReceiveResult result = await socket.ReceiveAsync(buffer, cancellationToken);
+                    WebSocketReceiveResult result = await socket.ReceiveAsync(buffer, cancellationToken).ConfigureAwait(false);
 
                     switch (result.MessageType)
                     {
@@ -72,7 +73,7 @@ namespace osu.Game.Online.Notifications.WebSocket
                                     break;
                                 }
 
-                                await onMessageReceivedAsync(message);
+                                await onMessageReceivedAsync(message).ConfigureAwait(false);
                             }
 
                             break;
@@ -81,12 +82,12 @@ namespace osu.Game.Online.Notifications.WebSocket
                             throw new NotImplementedException("Binary message type not supported.");
 
                         case WebSocketMessageType.Close:
-                            throw new Exception("Connection closed by remote host.");
+                            throw new WebException("Connection closed by remote host.");
                     }
                 }
                 catch (Exception ex)
                 {
-                    await InvokeClosed(ex);
+                    await InvokeClosed(ex).ConfigureAwait(false);
                     return;
                 }
             }
@@ -109,7 +110,7 @@ namespace osu.Game.Online.Notifications.WebSocket
             if (socket.State != WebSocketState.Open)
                 return;
 
-            await socket.SendAsync(Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(message)), WebSocketMessageType.Text, true, cancellationToken);
+            await socket.SendAsync(Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(message)), WebSocketMessageType.Text, true, cancellationToken).ConfigureAwait(false);
         }
 
         private async Task onMessageReceivedAsync(SocketMessage message)
@@ -141,7 +142,7 @@ namespace osu.Game.Online.Notifications.WebSocket
                     Debug.Assert(messageData != null);
 
                     foreach (var msg in messageData.Messages)
-                        HandleChannelJoined(await getChannel(msg.ChannelId));
+                        HandleChannelJoined(await getChannel(msg.ChannelId).ConfigureAwait(false));
 
                     HandleMessages(messageData.Messages);
                     break;
@@ -150,7 +151,7 @@ namespace osu.Game.Online.Notifications.WebSocket
 
         private async Task<Channel> getChannel(long channelId)
         {
-            if (channelsMap.TryGetValue(channelId, out Channel channel))
+            if (channelsMap.TryGetValue(channelId, out Channel? channel))
                 return channel;
 
             var tsc = new TaskCompletionSource<Channel>();
@@ -166,13 +167,13 @@ namespace osu.Game.Online.Notifications.WebSocket
 
             API.Queue(req);
 
-            return await tsc.Task;
+            return await tsc.Task.ConfigureAwait(false);
         }
 
         public override async ValueTask DisposeAsync()
         {
-            await base.DisposeAsync();
+            await base.DisposeAsync().ConfigureAwait(false);
-            await closeAsync();
+            await closeAsync().ConfigureAwait(false);
             socket.Dispose();
         }
     }

osu.Game/Online/Notifications/WebSocket/WebSocketNotificationsClientConnector.cs

@@ -32,7 +32,7 @@ namespace osu.Game.Online.Notifications.WebSocket
             req.Failure += ex => tcs.SetException(ex);
             api.Queue(req);
 
-            string endpoint = await tcs.Task;
+            string endpoint = await tcs.Task.ConfigureAwait(false);
 
             ClientWebSocket socket = new ClientWebSocket();
             socket.Options.SetRequestHeader(@"Authorization", @$"Bearer {api.AccessToken}");

osu.Game/Online/PersistentEndpointClientConnector.cs

@@ -65,11 +65,11 @@ namespace osu.Game.Online
             {
                 case APIState.Failing:
                 case APIState.Offline:
-                    await disconnect(true);
+                    await disconnect(true).ConfigureAwait(true);
                     break;
 
                 case APIState.Online:
-                    await connect();
+                    await connect().ConfigureAwait(true);
                     break;
             }
         }
@@ -147,7 +147,7 @@ namespace osu.Game.Online
         {
             bool hasBeenCancelled = cancellationToken.IsCancellationRequested;
 
-            await disconnect(true);
+            await disconnect(true).ConfigureAwait(false);
 
             if (ex != null)
                 await handleErrorAndDelay(ex, CancellationToken.None).ConfigureAwait(false);

osu.Game/Online/SignalRDerivedTypeWorkaroundJsonConverter.cs

@@ -33,7 +33,8 @@ namespace osu.Game.Online
 
             object? instance = Activator.CreateInstance(resolvedType);
 
-            jsonSerializer.Populate(obj["$value"]!.CreateReader(), instance);
+            if (instance != null)
+                jsonSerializer.Populate(obj["$value"]!.CreateReader(), instance);
 
             return instance;
         }

osu.Game/Online/Spectator/OnlineSpectatorClient.cs

@@ -56,7 +56,7 @@ namespace osu.Game.Online.Spectator
 
             try
             {
-                await connection.InvokeAsync(nameof(ISpectatorServer.BeginPlaySession), scoreToken, state);
+                await connection.InvokeAsync(nameof(ISpectatorServer.BeginPlaySession), scoreToken, state).ConfigureAwait(false);
             }
             catch (Exception exception)
             {
@@ -64,8 +64,8 @@ namespace osu.Game.Online.Spectator
                 {
                     Debug.Assert(connector != null);
 
-                    await connector.Reconnect();
+                    await connector.Reconnect().ConfigureAwait(false);
-                    await BeginPlayingInternal(scoreToken, state);
+                    await BeginPlayingInternal(scoreToken, state).ConfigureAwait(false);
                 }
 
                 // Exceptions can occur if, for instance, the locally played beatmap doesn't have a server-side counterpart.

osu.Game/Online/Spectator/SpectatorScoreProcessor.cs

@@ -184,7 +184,7 @@ namespace osu.Game.Online.Spectator
                 Header = header;
             }
 
-            public int CompareTo(TimedFrame other) => Time.CompareTo(other.Time);
+            public int CompareTo(TimedFrame? other) => Time.CompareTo(other?.Time);
         }
     }
 }

osu.Game/OsuGame.cs

@@ -16,6 +16,7 @@ using osu.Framework.Allocation;
 using osu.Framework.Audio;
 using osu.Framework.Bindables;
 using osu.Framework.Configuration;
+using osu.Framework.Extensions;
 using osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Framework.Extensions.TypeExtensions;
 using osu.Framework.Graphics;
@@ -332,7 +333,7 @@ namespace osu.Game
         /// <param name="link">The link to load.</param>
         public void HandleLink(LinkDetails link) => Schedule(() =>
         {
-            string argString = link.Argument.ToString();
+            string argString = link.Argument.ToString() ?? string.Empty;
 
             switch (link.Action)
             {
@@ -406,6 +407,16 @@ namespace osu.Game
             if (url.StartsWith('/'))
                 url = $"{API.APIEndpointUrl}{url}";
 
+            if (!url.CheckIsValidUrl())
+            {
+                Notifications.Post(new SimpleErrorNotification
+                {
+                    Text = $"The URL {url} has an unsupported or dangerous protocol and will not be opened.",
+                });
+
+                return;
+            }
+
             externalLinkOpener.OpenUrlExternally(url, bypassExternalUrlWarning);
         });
 
@@ -1031,6 +1042,8 @@ namespace osu.Game
             {
                 if (entry.Level < LogLevel.Important || entry.Target > LoggingTarget.Database) return;
 
+                Debug.Assert(entry.Target != null);
+
                 const int short_term_display_limit = 3;
 
                 if (recentLogCount < short_term_display_limit)
@@ -1043,7 +1056,7 @@ namespace osu.Game
                 }
                 else if (recentLogCount == short_term_display_limit)
                 {
-                    string logFile = $@"{entry.Target.ToString().ToLowerInvariant()}.log";
+                    string logFile = $@"{entry.Target.Value.ToString().ToLowerInvariant()}.log";
 
                     Schedule(() => Notifications.Post(new SimpleNotification
                     {

osu.Game/Overlays/ChatOverlay.cs

@@ -352,11 +352,13 @@ namespace osu.Game.Overlays
 
         protected virtual DrawableChannel CreateDrawableChannel(Channel newChannel) => new DrawableChannel(newChannel);
 
-        private void joinedChannelsChanged(object sender, NotifyCollectionChangedEventArgs args)
+        private void joinedChannelsChanged(object? sender, NotifyCollectionChangedEventArgs args)
         {
             switch (args.Action)
             {
                 case NotifyCollectionChangedAction.Add:
+                    Debug.Assert(args.NewItems != null);
+
                     IEnumerable<Channel> newChannels = args.NewItems.OfType<Channel>().Where(isChatChannel);
 
                     foreach (var channel in newChannels)
@@ -365,6 +367,8 @@ namespace osu.Game.Overlays
                     break;
 
                 case NotifyCollectionChangedAction.Remove:
+                    Debug.Assert(args.OldItems != null);
+
                     IEnumerable<Channel> leftChannels = args.OldItems.OfType<Channel>().Where(isChatChannel);
 
                     foreach (var channel in leftChannels)
@@ -384,7 +388,7 @@ namespace osu.Game.Overlays
             }
         }
 
-        private void availableChannelsChanged(object sender, NotifyCollectionChangedEventArgs args)
+        private void availableChannelsChanged(object? sender, NotifyCollectionChangedEventArgs args)
             => channelListing.UpdateAvailableChannels(channelManager.AvailableChannels);
 
         private void handleChatMessage(string message)

osu.Game/Overlays/Comments/DrawableComment.cs

@@ -19,6 +19,7 @@ using System;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Extensions.IEnumerableExtensions;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using osu.Framework.Extensions.LocalisationExtensions;
 using osu.Framework.Localisation;
 using osu.Framework.Platform;
@@ -360,6 +361,8 @@ namespace osu.Game.Overlays.Comments
                 switch (args.Action)
                 {
                     case NotifyCollectionChangedAction.Add:
+                        Debug.Assert(args.NewItems != null);
+
                         onRepliesAdded(args.NewItems.Cast<DrawableComment>());
                         break;
 

osu.Game/Overlays/FirstRunSetupOverlay.cs

@@ -301,7 +301,7 @@ namespace osu.Game.Overlays
 
             if (currentStepIndex < steps.Count)
             {
-                var nextScreen = (Screen)Activator.CreateInstance(steps[currentStepIndex.Value]);
+                var nextScreen = (Screen)Activator.CreateInstance(steps[currentStepIndex.Value])!;
 
                 loadingShowDelegate = Scheduler.AddDelayed(() => loading.Show(), 200);
                 nextScreen.OnLoadComplete += _ =>

osu.Game/Overlays/Profile/Sections/Historical/DrawableMostPlayedBeatmap.cs

@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using System.Diagnostics;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -131,8 +130,6 @@ namespace osu.Game.Overlays.Profile.Sections.Historical
             {
                 var metadata = beatmapInfo.Metadata;
 
-                Debug.Assert(metadata != null);
-
                 return new Drawable[]
                 {
                     new OsuSpriteText

osu.Game/Overlays/Profile/Sections/Ranks/DrawableProfileScore.cs

@@ -4,7 +4,6 @@
 #nullable disable
 
 using System;
-using System.Diagnostics;
 using System.Linq;
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
@@ -269,8 +268,6 @@ namespace osu.Game.Overlays.Profile.Sections.Ranks
             {
                 var metadata = beatmapInfo.Metadata;
 
-                Debug.Assert(metadata != null);
-
                 return new Drawable[]
                 {
                     new OsuSpriteText

osu.Game/Overlays/Settings/Sections/Input/RulesetBindingsSection.cs

@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using System.Diagnostics;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Localisation;
@@ -29,8 +28,6 @@ namespace osu.Game.Overlays.Settings.Sections.Input
 
             var r = ruleset.CreateInstance();
 
-            Debug.Assert(r != null);
-
             foreach (int variant in r.AvailableVariants)
                 Add(new VariantBindingsSubsection(ruleset, variant));
         }

osu.Game/Rulesets/Mods/IMod.cs

@@ -55,6 +55,6 @@ namespace osu.Game.Rulesets.Mods
         /// <summary>
         /// Create a fresh <see cref="Mod"/> instance based on this mod.
         /// </summary>
-        Mod CreateInstance() => (Mod)Activator.CreateInstance(GetType());
+        Mod CreateInstance() => (Mod)Activator.CreateInstance(GetType())!;
     }
 }

osu.Game/Rulesets/Mods/Mod.cs

@@ -70,7 +70,7 @@ namespace osu.Game.Rulesets.Mods
 
                 foreach ((SettingSourceAttribute attr, PropertyInfo property) in this.GetOrderedSettingsSourceProperties())
                 {
-                    var bindable = (IBindable)property.GetValue(this);
+                    var bindable = (IBindable)property.GetValue(this)!;
 
                     if (!bindable.IsDefault)
                         tooltipTexts.Add($"{attr.Label} {bindable}");
@@ -134,7 +134,7 @@ namespace osu.Game.Rulesets.Mods
         /// </summary>
         public virtual Mod DeepClone()
         {
-            var result = (Mod)Activator.CreateInstance(GetType());
+            var result = (Mod)Activator.CreateInstance(GetType())!;
             result.CopyFrom(this);
             return result;
         }
@@ -150,8 +150,8 @@ namespace osu.Game.Rulesets.Mods
 
             foreach (var (_, prop) in this.GetSettingsSourceProperties())
             {
-                var targetBindable = (IBindable)prop.GetValue(this);
+                var targetBindable = (IBindable)prop.GetValue(this)!;
-                var sourceBindable = (IBindable)prop.GetValue(source);
+                var sourceBindable = (IBindable)prop.GetValue(source)!;
 
                 CopyAdjustedSetting(targetBindable, sourceBindable);
             }
@@ -183,9 +183,9 @@ namespace osu.Game.Rulesets.Mods
             }
         }
 
-        public bool Equals(IMod other) => other is Mod them && Equals(them);
+        public bool Equals(IMod? other) => other is Mod them && Equals(them);
 
-        public bool Equals(Mod other)
+        public bool Equals(Mod? other)
         {
             if (ReferenceEquals(null, other)) return false;
             if (ReferenceEquals(this, other)) return true;
@@ -209,16 +209,16 @@ namespace osu.Game.Rulesets.Mods
         /// <summary>
         /// Reset all custom settings for this mod back to their defaults.
         /// </summary>
-        public virtual void ResetSettingsToDefaults() => CopyFrom((Mod)Activator.CreateInstance(GetType()));
+        public virtual void ResetSettingsToDefaults() => CopyFrom((Mod)Activator.CreateInstance(GetType())!);
 
         private class ModSettingsEqualityComparer : IEqualityComparer<IBindable>
         {
             public static ModSettingsEqualityComparer Default { get; } = new ModSettingsEqualityComparer();
 
-            public bool Equals(IBindable x, IBindable y)
+            public bool Equals(IBindable? x, IBindable? y)
             {
-                object xValue = x.GetUnderlyingSettingValue();
+                object? xValue = x?.GetUnderlyingSettingValue();
-                object yValue = y.GetUnderlyingSettingValue();
+                object? yValue = y?.GetUnderlyingSettingValue();
 
                 return EqualityComparer<object>.Default.Equals(xValue, yValue);
             }

osu.Game/Rulesets/Objects/SliderPath.cs

@@ -6,6 +6,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using Newtonsoft.Json;
 using osu.Framework.Bindables;
@@ -57,12 +58,16 @@ namespace osu.Game.Rulesets.Objects
                 switch (args.Action)
                 {
                     case NotifyCollectionChangedAction.Add:
+                        Debug.Assert(args.NewItems != null);
+
                         foreach (var c in args.NewItems.Cast<PathControlPoint>())
                             c.Changed += invalidate;
                         break;
 
                     case NotifyCollectionChangedAction.Reset:
                     case NotifyCollectionChangedAction.Remove:
+                        Debug.Assert(args.OldItems != null);
+
                         foreach (var c in args.OldItems.Cast<PathControlPoint>())
                             c.Changed -= invalidate;
                         break;