Extrapolate DerivesFromModuleBase() to an extension method

src/Discord.Net.Analyzers/GuildAccessAnalyzer.cs

@@ -41,7 +41,7 @@ namespace Discord.Analyzers
             // Bail out if the containing class doesn't derive from 'ModuleBase<T>'
             var classNode = context.Node.FirstAncestorOrSelf<TypeDeclarationSyntax>();
             var classSymbol = context.SemanticModel.GetDeclaredSymbol(classNode);
-            if (!DerivesFromModuleBase(classSymbol))
+            if (!classSymbol.DerivesFromModuleBase())
                 return;
 
             // Bail out if the containing method isn't marked with '[Command]'
@@ -66,20 +66,5 @@ namespace Discord.Analyzers
 
         private static readonly Func<AttributeData, bool> _attributeDataPredicate =
             (a => a.AttributeClass.Name == nameof(RequireContextAttribute));
-
-        private static readonly string _moduleBaseName = typeof(ModuleBase<>).Name;
-
-        private static bool DerivesFromModuleBase(INamedTypeSymbol symbol)
-        {
-            var bType = symbol.BaseType;
-            while (bType != null)
-            {
-                if (bType.MetadataName == _moduleBaseName)
-                    return true;
-
-                bType = bType.BaseType;
-            }
-            return false;
-        }
     }
 }

src/Discord.Net.Analyzers/SymbolExtensions.cs

@@ -0,0 +1,24 @@
+using System;
+using Microsoft.CodeAnalysis;
+using Discord.Commands;
+
+namespace Discord.Analyzers
+{
+    internal static class SymbolExtensions
+    {
+        private static readonly string _moduleBaseName = typeof(ModuleBase<>).Name;
+
+        public static bool DerivesFromModuleBase(this INamedTypeSymbol symbol)
+        {
+            var bType = symbol.BaseType;
+            while (bType != null)
+            {
+                if (bType.MetadataName == _moduleBaseName)
+                    return true;
+
+                bType = bType.BaseType;
+            }
+            return false;
+        }
+    }
+}

test/Discord.Net.Tests/AnalyzerTests/TestModule.cs

@@ -1,12 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using Discord.Commands;
-
-namespace Test
-{
-    public class TestModule : ModuleBase<ICommandContext>
-    {
-        [Command("test"), RequireContext(ContextType.Group)]
-        public Task TestCmd() => ReplyAsync(Context.Guild.Name);
-    }
-}