Extract invariant instantiation info extension method

osu.Game/Extensions/TypeExtensions.cs

@@ -0,0 +1,31 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using System.Linq;
+
+namespace osu.Game.Extensions
+{
+    internal static class TypeExtensions
+    {
+        /// <summary>
+        /// Returns <paramref name="type"/>'s <see cref="Type.AssemblyQualifiedName"/>
+        /// with the assembly version, culture and public key token values removed.
+        /// </summary>
+        /// <remarks>
+        /// This method is usually used in extensibility scenarios (i.e. for custom rulesets or skins)
+        /// when a version-agnostic identifier associated with a C# class - potentially originating from
+        /// an external assembly - is needed.
+        /// Leaving only the type and assembly names in such a scenario allows to preserve compatibility
+        /// across assembly versions.
+        /// </remarks>
+        internal static string GetInvariantInstantiationInfo(this Type type)
+        {
+            string assemblyQualifiedName = type.AssemblyQualifiedName;
+            if (assemblyQualifiedName == null)
+                throw new ArgumentException($"{type}'s assembly-qualified name is null. Ensure that it is a concrete type and not a generic type parameter.", nameof(type));
+
+            return string.Join(',', assemblyQualifiedName.Split(',').Take(2));
+        }
+    }
+}

osu.Game/Rulesets/Ruleset.cs

@@ -26,6 +26,7 @@ using JetBrains.Annotations;
 using osu.Framework.Extensions;
 using osu.Framework.Extensions.EnumExtensions;
 using osu.Framework.Testing;
+using osu.Game.Extensions;
 using osu.Game.Rulesets.Filter;
 using osu.Game.Screens.Ranking.Statistics;
 
@@ -135,7 +136,7 @@ namespace osu.Game.Rulesets
                 Name = Description,
                 ShortName = ShortName,
                 ID = (this as ILegacyRuleset)?.LegacyID,
-                InstantiationInfo = GetType().AssemblyQualifiedName,
+                InstantiationInfo = GetType().GetInvariantInstantiationInfo(),
                 Available = true,
             };
         }

osu.Game/Rulesets/RulesetInfo.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using Newtonsoft.Json;
 using osu.Framework.Testing;
 
@@ -18,20 +17,7 @@ namespace osu.Game.Rulesets
 
         public string ShortName { get; set; }
 
-        private string instantiationInfo;
+        public string InstantiationInfo { get; set; }
-
-        public string InstantiationInfo
-        {
-            get => instantiationInfo;
-            set => instantiationInfo = abbreviateInstantiationInfo(value);
-        }
-
-        private string abbreviateInstantiationInfo(string value)
-        {
-            // exclude version onwards, matching only on namespace and type.
-            // this is mainly to allow for new versions of already loaded rulesets to "upgrade" from old.
-            return string.Join(',', value.Split(',').Take(2));
-        }
 
         [JsonIgnore]
         public bool Available { get; set; }

osu.Game/Skinning/SkinInfo.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using osu.Framework.IO.Stores;
 using osu.Game.Configuration;
 using osu.Game.Database;
@@ -25,20 +24,7 @@ namespace osu.Game.Skinning
 
         public string Creator { get; set; }
 
-        private string instantiationInfo;
+        public string InstantiationInfo { get; set; }
-
-        public string InstantiationInfo
-        {
-            get => instantiationInfo;
-            set => instantiationInfo = abbreviateInstantiationInfo(value);
-        }
-
-        private string abbreviateInstantiationInfo(string value)
-        {
-            // exclude version onwards, matching only on namespace and type.
-            // this is mainly to allow for new versions of already loaded rulesets to "upgrade" from old.
-            return string.Join(',', value.Split(',').Take(2));
-        }
 
         public virtual Skin CreateInstance(IResourceStore<byte[]> legacyDefaultResources, IStorageResourceProvider resources)
         {

osu.Game/Skinning/SkinManager.cs

@@ -22,6 +22,7 @@ using osu.Framework.Testing;
 using osu.Framework.Utils;
 using osu.Game.Audio;
 using osu.Game.Database;
+using osu.Game.Extensions;
 using osu.Game.IO;
 using osu.Game.IO.Archives;
 
@@ -124,7 +125,7 @@ namespace osu.Game.Skinning
 
             var instance = GetSkin(model);
 
-            model.InstantiationInfo ??= instance.GetType().AssemblyQualifiedName;
+            model.InstantiationInfo ??= instance.GetType().GetInvariantInstantiationInfo();
 
             if (model.Name?.Contains(".osk", StringComparison.OrdinalIgnoreCase) == true)
                 populateMetadata(model, instance);