Refactor GeneratesMethod target resolution to use named constructor parameter mapping (#25)

* Initial plan

* Refactor GeneratesMethod argument lookup to named parameter matching

Co-authored-by: dex3r <3155725+dex3r@users.noreply.github.com>

* Apply explicit parameter-index lookup style cleanup

Co-authored-by: dex3r <3155725+dex3r@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: dex3r <3155725+dex3r@users.noreply.github.com>

Author: Copilot

MattSourceGenHelpers.Generators/GeneratesMethodGenerationTargetCollector.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using MattSourceGenHelpers.Abstractions;
 using System.Collections.Immutable;
 using static MattSourceGenHelpers.Generators.Consts;
 
@@ -54,7 +55,23 @@ internal static List<GeneratesMethodGenerationTarget> Collect(
                 continue;
             }
 
-            string? targetMethodName = attribute.ConstructorArguments[0].Value?.ToString();
+            ImmutableArray<IParameterSymbol> constructorParameters = attribute.AttributeConstructor?.Parameters ?? [];
+            int targetMethodNameArgumentIndex = -1;
+            for (int parameterIndex = 0; parameterIndex < constructorParameters.Length; parameterIndex++)
+            {
+                IParameterSymbol constructorParameter = constructorParameters[parameterIndex];
+                if (constructorParameter.Name.Equals(nameof(GeneratesMethod.SameClassMethodName), StringComparison.OrdinalIgnoreCase))
+                {
+                    targetMethodNameArgumentIndex = parameterIndex;
+                    break;
+                }
+            }
+            if (targetMethodNameArgumentIndex < 0 || targetMethodNameArgumentIndex >= attribute.ConstructorArguments.Length)
+            {
+                continue;
+            }
+
+            string? targetMethodName = attribute.ConstructorArguments[targetMethodNameArgumentIndex].Value?.ToString();
             if (string.IsNullOrEmpty(targetMethodName))
             {
                 continue;

MattSourceGenHelpers.Tests/UnitTest1.cs

@@ -45,7 +45,7 @@ public partial class TestColorsClass
 {
     public partial string GetAllColorsString();
 
-    [GeneratesMethod(nameof(GetAllColorsString))]
+    [GeneratesMethod(sameClassMethodName: nameof(GetAllColorsString))]
     private static string GetAllColorsString_Generator() =>
         string.Join(", ", Enum.GetNames<TestColorsEnum>());
 }