From 23c4f9910e5bba1c0b556bb3838d9eea87cdd6dd Mon Sep 17 00:00:00 2001
From: Dan Balasescu <smoogipoo@smgi.me>
Date: Fri, 25 Mar 2022 15:53:55 +0900
Subject: [PATCH] Apply notnull constraint

---
 osu.Game/Skinning/ISkin.cs                   | 4 +++-
 osu.Game/Skinning/LegacySkin.cs              | 6 +++---
 osu.Game/Skinning/ResourceStoreBackedSkin.cs | 5 ++++-
 osu.Game/Skinning/Skin.cs                    | 4 +++-
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/osu.Game/Skinning/ISkin.cs b/osu.Game/Skinning/ISkin.cs
index 4b14dcfd62..414a316dec 100644
--- a/osu.Game/Skinning/ISkin.cs
+++ b/osu.Game/Skinning/ISkin.cs
@@ -52,6 +52,8 @@ public interface ISkin
         /// </summary>
         /// <param name="lookup">The requested configuration value.</param>
         /// <returns>A matching value boxed in an <see cref="IBindable{TValue}"/>, or null if unavailable.</returns>
-        IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup);
+        IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
+            where TLookup : notnull
+            where TValue : notnull;
     }
 }
diff --git a/osu.Game/Skinning/LegacySkin.cs b/osu.Game/Skinning/LegacySkin.cs
index a3c08f4ba2..92713023f4 100644
--- a/osu.Game/Skinning/LegacySkin.cs
+++ b/osu.Game/Skinning/LegacySkin.cs
@@ -282,6 +282,7 @@ protected override void ParseConfigurationStream(Stream stream)
             => source.ImageLookups.TryGetValue(lookup, out string image) ? new Bindable<string>(image) : null;
 
         private IBindable<TValue>? legacySettingLookup<TValue>(SkinConfiguration.LegacySetting legacySetting)
+            where TValue : notnull
         {
             switch (legacySetting)
             {
@@ -294,10 +295,9 @@ protected override void ParseConfigurationStream(Stream stream)
         }
 
         private IBindable<TValue>? genericLookup<TLookup, TValue>(TLookup lookup)
+            where TLookup : notnull
+            where TValue : notnull
         {
-            if (lookup == null)
-                return null;
-
             try
             {
                 if (Configuration.ConfigDictionary.TryGetValue(lookup.ToString(), out string val))
diff --git a/osu.Game/Skinning/ResourceStoreBackedSkin.cs b/osu.Game/Skinning/ResourceStoreBackedSkin.cs
index 4787b5a4e9..48286bff59 100644
--- a/osu.Game/Skinning/ResourceStoreBackedSkin.cs
+++ b/osu.Game/Skinning/ResourceStoreBackedSkin.cs
@@ -46,7 +46,10 @@ public ResourceStoreBackedSkin(IResourceStore<byte[]> resources, GameHost host,
             return null;
         }
 
-        public IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup) => null;
+        public IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
+            where TLookup : notnull
+            where TValue : notnull
+            => null;
 
         public void Dispose()
         {
diff --git a/osu.Game/Skinning/Skin.cs b/osu.Game/Skinning/Skin.cs
index 2766e58c96..324ed90a67 100644
--- a/osu.Game/Skinning/Skin.cs
+++ b/osu.Game/Skinning/Skin.cs
@@ -50,7 +50,9 @@ public abstract class Skin : IDisposable, ISkin
 
         public abstract Texture? GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT);
 
-        public abstract IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup);
+        public abstract IBindable<TValue>? GetConfig<TLookup, TValue>(TLookup lookup)
+            where TLookup : notnull
+            where TValue : notnull;
 
         /// <summary>
         /// Construct a new skin.