extensions rework pt1

Railway.SourceGenerator/Executors/EnsureExtensionsExecutor.cs

@@ -2,11 +2,11 @@ using System.Collections.Generic;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors;
 
 public sealed class EnsureExtensionsExecutor : IGeneratorExecutor
 {
-    public void Execute(SourceProductionContext context, Compilation source)
+    public void Execute(IncrementalGeneratorPostInitializationContext context)
     {
         var methods = GenerateMethods();
         var code = $$"""

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultAppendExecutor.cs

@@ -3,11 +3,13 @@ using System.Linq;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
 
-internal sealed class ResultAppendExecutor : ResultExtensionsExecutor
+internal class ResultAppendExecutor : ResultExtensionsExecutor
 {
     protected override string ExtensionType => "Append";
+    protected override string NamespaceName => "Just.Railway";
+    protected override string PartialClassName => "ResultExtensions";
 
     protected override void GenerateHelperMethods(StringBuilder sb)
     {
@@ -89,19 +91,17 @@ internal sealed class ResultAppendExecutor : ResultExtensionsExecutor
         """);
 
         GenerateAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, resultValueExpansion);
-        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
 
         if (argCount < Constants.MaxResultTupleSize)
         {
             GenerateExpandedMethods(sb, templateArgNames, resultTypeDef, resultValueExpansion);
             GenerateExpandedAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, resultValueExpansion);
-            GenerateExpandedAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
         }
 
         sb.AppendLine("#endregion");
     }
 
-    private void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
+    protected static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
     {
         string methodTemplateDecl = GenerateTemplateDecl(templateArgNames);
 
@@ -192,7 +192,7 @@ internal sealed class ResultAppendExecutor : ResultExtensionsExecutor
         """);
     }
 
-    private void GenerateExpandedAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
+    protected static void GenerateExpandedAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
     {
         var expandedTemplateArgNames = templateArgNames.Add("TNext");
         string resultExpandedTypeDef = GenerateResultTypeDef(expandedTemplateArgNames);

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultBindExecutor.cs

@@ -3,11 +3,13 @@ using System.Linq;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
 
-internal sealed class ResultBindExecutor : ResultExtensionsExecutor
+internal class ResultBindExecutor : ResultExtensionsExecutor
 {
     protected override string ExtensionType => "Bind";
+    protected override string NamespaceName => "Just.Railway";
+    protected override string PartialClassName => "ResultExtensions";
 
     protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
     {
@@ -37,12 +39,11 @@ internal sealed class ResultBindExecutor : ResultExtensionsExecutor
         """);
 
         GenerateAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, resultValueExpansion);
-        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
 
         sb.AppendLine("#endregion");
     }
 
-    private static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
+    protected static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
     {
         string methodTemplateDecl = GenerateTemplateDecl(templateArgNames.Add("R"));
         string bindTemplateDecl = GenerateTemplateDecl(templateArgNames.Add("Result<R>"));

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultCombineExecutor.cs

@@ -5,11 +5,11 @@ using System.Linq;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
 
 internal sealed class ResultCombineExecutor : IGeneratorExecutor
 {
-    public void Execute(SourceProductionContext context, Compilation source)
+    public void Execute(IncrementalGeneratorPostInitializationContext context)
     {
         var methods = GenerateCombineMethods();
         var code = $$"""

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultExtendExecutor.cs

@@ -3,11 +3,13 @@ using System.Linq;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
 
-internal sealed class ResultExtendExecutor : ResultExtensionsExecutor
+internal class ResultExtendExecutor : ResultExtensionsExecutor
 {
     protected override string ExtensionType => "Extend";
+    protected override string NamespaceName => "Just.Railway";
+    protected override string PartialClassName => "ResultExtensions";
 
     protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
     {
@@ -58,12 +60,11 @@ internal sealed class ResultExtendExecutor : ResultExtensionsExecutor
         """);
 
         GenerateAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, resultValueExpansion);
-        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
 
         sb.AppendLine("#endregion");
     }
 
-    private static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
+    protected static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
     {
         var expandedTemplateArgNames = templateArgNames.Add("R");
         string resultExpandedTypeDef = GenerateResultTypeDef(expandedTemplateArgNames);

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultMapExecutor.cs

@@ -1,13 +1,17 @@
 using System.Collections.Immutable;
 using System.Linq;
 using System.Text;
+using Just.Railway.SourceGen.Executors.ResultExtensions;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors;
 
-internal sealed class ResultMapExecutor : ResultExtensionsExecutor
+internal class ResultMapExecutor : ResultExtensionsExecutor
 {
     protected override string ExtensionType => "Map";
+    protected override string NamespaceName => "Just.Railway";
+    protected override string PartialClassName => "ResultExtensions";
+
     protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
     {
         var templateArgNames = Enumerable.Range(1, argCount)
@@ -35,12 +39,11 @@ internal sealed class ResultMapExecutor : ResultExtensionsExecutor
         """);
 
         GenerateAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, resultValueExpansion);
-        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
 
         sb.AppendLine("#endregion");
     }
 
-    private static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
+    protected static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
     {
         var methodTemplateArgNames = templateArgNames.Add("R");
         string methodTemplateDecl = GenerateTemplateDecl(methodTemplateArgNames);

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultMatchExecutor.cs

@@ -3,11 +3,13 @@ using System.Linq;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
 
-internal sealed class ResultMatchExecutor : ResultExtensionsExecutor
+internal class ResultMatchExecutor : ResultExtensionsExecutor
 {
     protected override string ExtensionType => "Match";
+    protected override string NamespaceName => "Just.Railway";
+    protected override string PartialClassName => "ResultExtensions";
 
     protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
     {
@@ -36,12 +38,11 @@ internal sealed class ResultMatchExecutor : ResultExtensionsExecutor
         """);
 
         GenerateAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, resultValueExpansion);
-        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
 
         sb.AppendLine("#endregion");
     }
 
-    private static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
+    protected static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
     {
         var methodTemplateArgNames = templateArgNames.Add("R");
         string methodTemplateDecl = GenerateTemplateDecl(methodTemplateArgNames);

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultTapExecutor.cs

@@ -3,11 +3,13 @@ using System.Linq;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
 
-internal sealed class ResultTapExecutor : ResultExtensionsExecutor
+internal class ResultTapExecutor : ResultExtensionsExecutor
 {
     protected override string ExtensionType => "Tap";
+    protected override string NamespaceName => "Just.Railway";
+    protected override string PartialClassName => "ResultExtensions";
 
     protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
     {
@@ -24,7 +26,7 @@ internal sealed class ResultTapExecutor : ResultExtensionsExecutor
         sb.AppendLine($$"""
         [PureAttribute]
         [GeneratedCodeAttribute("{{nameof(ResultTapExecutor)}}", "1.0.0.0")]
-        public static ref readonly {{resultTypeDef}} Tap{{methodTemplateDecl}}(this in {{resultTypeDef}} result, Action{{methodTemplateDecl}}? onSuccess = null, Action<Error>? onFailure = null)
+        public static {{resultTypeDef}} Tap{{methodTemplateDecl}}(this in {{resultTypeDef}} result, Action{{methodTemplateDecl}}? onSuccess = null, Action<Error>? onFailure = null)
         {
             switch (result.State)
             {
@@ -37,17 +39,16 @@ internal sealed class ResultTapExecutor : ResultExtensionsExecutor
 
                 default: throw new ResultNotInitializedException(nameof(result));
             }
-            return ref result;
+            return result;
         }
         """);
 
         GenerateAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, resultValueExpansion);
-        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
 
         sb.AppendLine("#endregion");
     }
 
-    private static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
+    protected static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string resultValueExpansion)
     {
         string methodTemplateDecl = GenerateTemplateDecl(templateArgNames);
         string asyncActionTemplateDecl = GenerateTemplateDecl(templateArgNames.Add(taskType));

Railway.SourceGenerator/Executors/ResultExtensions/MainExtensions/ResultTryRecoverExecutor.cs

@@ -2,11 +2,14 @@ using System.Collections.Immutable;
 using System.Linq;
 using System.Text;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
 
-internal sealed class ResultTryRecoverExecutor : ResultExtensionsExecutor
+internal class ResultTryRecoverExecutor : ResultExtensionsExecutor
 {
     protected override string ExtensionType => "TryRecover";
+    protected override string NamespaceName => "Just.Railway";
+    protected override string PartialClassName => "ResultExtensions";
+
     protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
     {
         if (argCount > 1) return;
@@ -34,11 +37,11 @@ internal sealed class ResultTryRecoverExecutor : ResultExtensionsExecutor
         """);
 
         GenerateAsyncMethods("Task", string.Empty, sb, templateArgNames, resultTypeDef, methodTemplateDecl);
-        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, methodTemplateDecl);
 
         sb.AppendLine("#endregion");
     }
-    private static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string methodTemplateDecl)
+
+    protected static void GenerateAsyncMethods(string taskType, string methodSuffix, StringBuilder sb, ImmutableArray<string> templateArgNames, string resultTypeDef, string methodTemplateDecl)
     {
         sb.AppendLine($$"""
         [PureAttribute]

Railway.SourceGenerator/Executors/ResultExtensions/ResultExtensionsExecutor.cs

@@ -2,11 +2,11 @@ using System.Collections.Immutable;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors.ResultExtensions;
 
 internal abstract class ResultExtensionsExecutor : IGeneratorExecutor
 {
-    public void Execute(SourceProductionContext context, Compilation source)
+    public void Execute(IncrementalGeneratorPostInitializationContext context)
     {
         var methods = GenerateMethods();
         var code = $$"""
@@ -16,15 +16,15 @@ internal abstract class ResultExtensionsExecutor : IGeneratorExecutor
         using System.Diagnostics.Contracts;
         using System.CodeDom.Compiler;
 
-        namespace Just.Railway;
+        namespace {{NamespaceName}};
 
-        public static partial class ResultExtensions
+        public static partial class {{PartialClassName}}
         {
         {{methods}}
         }
         """;
 
-        context.AddSource($"ResultExtensions.{ExtensionType}.g.cs", code);
+        context.AddSource($"{PartialClassName}.{ExtensionType}.g.cs", code);
     }
 
     private string GenerateMethods()
@@ -87,6 +87,8 @@ internal abstract class ResultExtensionsExecutor : IGeneratorExecutor
     }
 
     protected abstract string ExtensionType { get; }
+    protected abstract string NamespaceName { get; }
+    protected abstract string PartialClassName { get; }
     protected abstract void GenerateMethodsForArgCount(StringBuilder sb, int argCount);
     protected virtual void GenerateHelperMethods(StringBuilder sb) {}
 }

Railway.SourceGenerator/Executors/ResultExtensions/ValueTaskExtensions/ResultValueTaskAppendExecutor.cs

@@ -0,0 +1,47 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
+
+internal class ResultValueTaskAppendExecutor : ResultAppendExecutor
+{
+    protected override string NamespaceName => "Just.Railway.ValueTaskExtensions";
+    protected override string PartialClassName => "ResultValueTaskExtensions";
+
+    protected override void GenerateHelperMethods(StringBuilder sb)
+    {
+        sb.AppendLine("""
+        private static IEnumerable<string> GetBottom(ResultState r1, ResultState r2, string firstArg = "result", string secondArg = "next")
+        {
+            if (r1 == ResultState.Bottom)
+                yield return firstArg;
+            if (r2 == ResultState.Bottom)
+                yield return secondArg;
+        }
+        """);
+    }
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        var templateArgNames = Enumerable.Range(1, argCount)
+            .Select(i => $"T{i}")
+            .ToImmutableArray();
+
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+        string resultValueExpansion = GenerateResultValueExpansion(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
+
+        if (argCount < Constants.MaxResultTupleSize)
+        {
+            GenerateExpandedAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
+        }
+
+        sb.AppendLine("#endregion");
+    }
+}

Railway.SourceGenerator/Executors/ResultExtensions/ValueTaskExtensions/ResultValueTaskBindExecutor.cs

@@ -0,0 +1,29 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
+
+internal class ResultValueTaskBindExecutor : ResultBindExecutor
+{
+    protected override string NamespaceName => "Just.Railway.ValueTaskExtensions";
+    protected override string PartialClassName => "ResultValueTaskExtensions";
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        var templateArgNames = Enumerable.Range(1, argCount)
+            .Select(i => $"T{i}")
+            .ToImmutableArray();
+
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+        string resultValueExpansion = GenerateResultValueExpansion(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
+
+        sb.AppendLine("#endregion");
+    }
+}

Railway.SourceGenerator/Executors/ResultExtensions/ValueTaskExtensions/ResultValueTaskExtendExecutor.cs

@@ -0,0 +1,35 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
+
+internal sealed class ResultValueTaskExtendExecutor : ResultExtendExecutor
+{
+    protected override string NamespaceName => "Just.Railway.ValueTaskExtensions";
+    protected override string PartialClassName => "ResultValueTaskExtensions";
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        if (argCount == 0 || argCount == Constants.MaxResultTupleSize)
+        {
+            return;
+        }
+
+        var templateArgNames = Enumerable.Range(1, argCount)
+            .Select(i => $"T{i}")
+            .ToImmutableArray();
+
+        var expandedTemplateArgNames = templateArgNames.Add("R");
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+        string resultValueExpansion = GenerateResultValueExpansion(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
+
+        sb.AppendLine("#endregion");
+    }
+}

Railway.SourceGenerator/Executors/ResultExtensions/ValueTaskExtensions/ResultValueTaskMapExecutor.cs

@@ -0,0 +1,28 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
+
+internal sealed class ResultValueTaskMapExecutor : ResultMapExecutor
+{
+    protected override string NamespaceName => "Just.Railway.ValueTaskExtensions";
+    protected override string PartialClassName => "ResultValueTaskExtensions";
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        var templateArgNames = Enumerable.Range(1, argCount)
+            .Select(i => $"T{i}")
+            .ToImmutableArray();
+
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+        string resultValueExpansion = GenerateResultValueExpansion(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
+
+        sb.AppendLine("#endregion");
+    }
+}

Railway.SourceGenerator/Executors/ResultExtensions/ValueTaskExtensions/ResultValueTaskMatchExecutor.cs

@@ -0,0 +1,29 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
+
+internal class ResultValueTaskMatchExecutor : ResultMatchExecutor
+{
+    protected override string NamespaceName => "Just.Railway.ValueTaskExtensions";
+    protected override string PartialClassName => "ResultValueTaskExtensions";
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        var templateArgNames = Enumerable.Range(1, argCount)
+            .Select(i => $"T{i}")
+            .ToImmutableArray();
+
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+        string resultValueExpansion = GenerateResultValueExpansion(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
+
+        sb.AppendLine("#endregion");
+    }
+}

Railway.SourceGenerator/Executors/ResultExtensions/ValueTaskExtensions/ResultValueTaskTapExecutor.cs

@@ -0,0 +1,29 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
+using Microsoft.CodeAnalysis;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
+
+internal class ResultValueTaskTapExecutor : ResultTapExecutor
+{
+    protected override string NamespaceName => "Just.Railway.ValueTaskExtensions";
+    protected override string PartialClassName => "ResultValueTaskExtensions";
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        var templateArgNames = Enumerable.Range(1, argCount)
+            .Select(i => $"T{i}")
+            .ToImmutableArray();
+
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+        string resultValueExpansion = GenerateResultValueExpansion(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, resultValueExpansion);
+
+        sb.AppendLine("#endregion");
+    }
+}

Railway.SourceGenerator/Executors/ResultExtensions/ValueTaskExtensions/ResultValueTaskTryRecoverExecutor.cs

@@ -0,0 +1,30 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
+
+namespace Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
+
+internal class ResultValueTaskTryRecoverExecutor : ResultTryRecoverExecutor
+{
+    protected override string NamespaceName => "Just.Railway.ValueTaskExtensions";
+    protected override string PartialClassName => "ResultValueTaskExtensions";
+
+
+    protected override void GenerateMethodsForArgCount(StringBuilder sb, int argCount)
+    {
+        if (argCount > 1) return;
+
+        var templateArgNames = Enumerable.Repeat("T", argCount)
+            .ToImmutableArray();
+
+        string methodTemplateDecl = GenerateTemplateDecl(templateArgNames);
+        string resultTypeDef = GenerateResultTypeDef(templateArgNames);
+
+        sb.AppendLine($"#region {resultTypeDef}");
+
+        GenerateAsyncMethods("ValueTask", "ValueTask", sb, templateArgNames, resultTypeDef, methodTemplateDecl);
+
+        sb.AppendLine("#endregion");
+    }
+}

Railway.SourceGenerator/Executors/TryExtensionsExecutor.cs

@@ -3,11 +3,11 @@ using System.Linq;
 using System.Text;
 using Microsoft.CodeAnalysis;
 
-namespace Just.Railway.SourceGen;
+namespace Just.Railway.SourceGen.Executors;
 
 public sealed class TryExtensionsExecutor : IGeneratorExecutor
 {
-    public void Execute(SourceProductionContext context, Compilation source)
+    public void Execute(IncrementalGeneratorPostInitializationContext context)
     {
         var methods = GenerateMethods();
         var code = $$"""
@@ -123,13 +123,13 @@ public sealed class TryExtensionsExecutor : IGeneratorExecutor
         }
         """);
 
-        GenerateAsyncMethods(sb, templateArgNames, actionTemplateDecl, funcTemplateDecl, argumentsDeclExpansion, argumentsExpansion, "Task");
-        GenerateAsyncMethods(sb, templateArgNames, actionTemplateDecl, funcTemplateDecl, argumentsDeclExpansion, argumentsExpansion, "ValueTask");
+        GenerateAsyncMethods(sb, templateArgNames, actionTemplateDecl, funcTemplateDecl, argumentsDeclExpansion, argumentsExpansion, "Task", string.Empty);
+        GenerateAsyncMethods(sb, templateArgNames, actionTemplateDecl, funcTemplateDecl, argumentsDeclExpansion, argumentsExpansion, "ValueTask", "ValueTask");
 
         sb.AppendLine("#endregion");
     }
 
-    private static void GenerateAsyncMethods(StringBuilder sb, ImmutableArray<string> templateArgNames, string actionTemplateDecl, string funcTemplateDecl, string argumentsDeclExpansion, string argumentsExpansion, string taskType)
+    private static void GenerateAsyncMethods(StringBuilder sb, ImmutableArray<string> templateArgNames, string actionTemplateDecl, string funcTemplateDecl, string argumentsDeclExpansion, string argumentsExpansion, string taskType, string methodSuffix)
     {
         string actionTaskTemplateDecl = GenerateTemplateDecl(templateArgNames.Add(taskType));
         string resultActionTaskTemplateDecl = GenerateTemplateDecl(templateArgNames.Add($"{taskType}<Result>"));
@@ -138,7 +138,7 @@ public sealed class TryExtensionsExecutor : IGeneratorExecutor
         sb.AppendLine($$"""
         [PureAttribute]
         [GeneratedCodeAttribute("{{nameof(TryExtensionsExecutor)}}", "1.0.0.0")]
-        public static async {{taskType}}<Result> Run{{actionTemplateDecl}}(Func{{actionTaskTemplateDecl}} action{{TrailingArguments(argumentsDeclExpansion)}})
+        public static async {{taskType}}<Result> Run{{methodSuffix}}{{actionTemplateDecl}}(Func{{actionTaskTemplateDecl}} action{{TrailingArguments(argumentsDeclExpansion)}})
         {
             try
             {
@@ -155,7 +155,7 @@ public sealed class TryExtensionsExecutor : IGeneratorExecutor
         sb.AppendLine($$"""
         [PureAttribute]
         [GeneratedCodeAttribute("{{nameof(TryExtensionsExecutor)}}", "1.0.0.0")]
-        public static async {{taskType}}<Result> Run{{actionTemplateDecl}}(Func{{resultActionTaskTemplateDecl}} action{{TrailingArguments(argumentsDeclExpansion)}})
+        public static async {{taskType}}<Result> Run{{methodSuffix}}{{actionTemplateDecl}}(Func{{resultActionTaskTemplateDecl}} action{{TrailingArguments(argumentsDeclExpansion)}})
         {
             try
             {
@@ -171,7 +171,7 @@ public sealed class TryExtensionsExecutor : IGeneratorExecutor
         sb.AppendLine($$"""
         [PureAttribute]
         [GeneratedCodeAttribute("{{nameof(TryExtensionsExecutor)}}", "1.0.0.0")]
-        public static async {{taskType}}<Result<TResult>> Run{{funcTemplateDecl}}(Func{{funcTaskTemplateDecl}} func{{TrailingArguments(argumentsDeclExpansion)}})
+        public static async {{taskType}}<Result<TResult>> Run{{methodSuffix}}{{funcTemplateDecl}}(Func{{funcTaskTemplateDecl}} func{{TrailingArguments(argumentsDeclExpansion)}})
         {
             try
             {
@@ -187,7 +187,7 @@ public sealed class TryExtensionsExecutor : IGeneratorExecutor
         sb.AppendLine($$"""
         [PureAttribute]
         [GeneratedCodeAttribute("{{nameof(TryExtensionsExecutor)}}", "1.0.0.0")]
-        public static async {{taskType}}<Result<TResult>> Run{{funcTemplateDecl}}(Func{{resultFuncTaskTemplateDecl}} func{{TrailingArguments(argumentsDeclExpansion)}})
+        public static async {{taskType}}<Result<TResult>> Run{{methodSuffix}}{{funcTemplateDecl}}(Func{{resultFuncTaskTemplateDecl}} func{{TrailingArguments(argumentsDeclExpansion)}})
         {
             try
             {

Railway.SourceGenerator/ExtensionsMethodGenerator.cs

@@ -1,4 +1,7 @@
 using System.Collections.Generic;
+using Just.Railway.SourceGen.Executors;
+using Just.Railway.SourceGen.Executors.ResultExtensions.MainExtensions;
+using Just.Railway.SourceGen.Executors.ResultExtensions.ValueTaskExtensions;
 using Microsoft.CodeAnalysis;
 
 namespace Just.Railway.SourceGen;
@@ -6,9 +9,10 @@ namespace Just.Railway.SourceGen;
 [Generator]
 public class ExtensionsMethodGenerator : IIncrementalGenerator
 {
-    private readonly IEnumerable<IGeneratorExecutor> _executors = new IGeneratorExecutor[]
-    {
+    private readonly IEnumerable<IGeneratorExecutor> _executors =
+    [
         new ResultCombineExecutor(),
+
         new ResultMatchExecutor(),
         new ResultMapExecutor(),
         new ResultBindExecutor(),
@@ -16,15 +20,24 @@ public class ExtensionsMethodGenerator : IIncrementalGenerator
         new ResultExtendExecutor(),
         new ResultTryRecoverExecutor(),
         new ResultAppendExecutor(),
+
+        new ResultValueTaskMatchExecutor(),
+        new ResultValueTaskMapExecutor(),
+        new ResultValueTaskBindExecutor(),
+        new ResultValueTaskTapExecutor(),
+        new ResultValueTaskExtendExecutor(),
+        new ResultValueTaskTryRecoverExecutor(),
+        new ResultValueTaskAppendExecutor(),
+
         new TryExtensionsExecutor(),
         new EnsureExtensionsExecutor(),
-    };
+    ];
 
     public void Initialize(IncrementalGeneratorInitializationContext context)
     {
         foreach (var executor in _executors)
         {
-            context.RegisterSourceOutput(context.CompilationProvider, executor.Execute);
+            context.RegisterPostInitializationOutput(executor.Execute);
         }
     }
 }

Railway.SourceGenerator/IGeneratorExecutor.cs

@@ -4,5 +4,5 @@ namespace Just.Railway.SourceGen;
 
 internal interface IGeneratorExecutor
 {
-    public abstract void Execute(SourceProductionContext context, Compilation source);
+    public abstract void Execute(IncrementalGeneratorPostInitializationContext context);
 }

Railway/Error.cs

@@ -206,6 +206,7 @@ public sealed class ExpectedError : Error
 {
     public ExpectedError(string type, string message)
     {
+        ArgumentNullException.ThrowIfNull(type);
         Type = type;
         Message = message;
     }
@@ -252,6 +253,7 @@ public sealed class ExceptionalError : Error
 
     public ExceptionalError(string type, string message)
     {
+        ArgumentNullException.ThrowIfNull(type);
         Type = type;
         Message = message;
     }
@@ -343,7 +345,7 @@ public sealed class ManyErrors : Error, IEnumerable<Error>, IReadOnlyList<Error>
     [Pure] public override string Type => "many_errors";
 
     private string? _lazyMessage = null;
-    [Pure] public override string Message => _lazyMessage ??= ToFullArrayString(_errors);
+    [Pure] public override string Message => _lazyMessage ??= ToFullArrayString(_errors); // not thread safe. wontfix
 
     [Pure] private static string ToFullArrayString(in ImmutableArray<Error> errors)
     {
@@ -428,7 +430,7 @@ public sealed class ManyErrors : Error, IEnumerable<Error>, IReadOnlyList<Error>
     }
 
     private int? _lazyHashCode = null;
-    [Pure] public override int GetHashCode() => _lazyHashCode ??= CalcHashCode(_errors);
+    [Pure] public override int GetHashCode() => _lazyHashCode ??= CalcHashCode(_errors); // not thread safe. wontfix
     private static int CalcHashCode(in ImmutableArray<Error> errors)
     {
         if (errors.IsEmpty)

Railway/ReflectionHelper.cs

@@ -7,13 +7,9 @@ internal static class ReflectionHelper
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool IsEqual<T>(T? left, T? right) => TypeReflectionCache<T>.IsEqualFunc(left, right);
 
-    [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static int Compare<T>(T? left, T? right) => TypeReflectionCache<T>.CompareFunc(left, right);
-
     private static class TypeReflectionCache<T>
     {
         public static readonly Func<T?, T?, bool> IsEqualFunc;
-        public static readonly Func<T?, T?, int> CompareFunc;
 
         static TypeReflectionCache()
         {
@@ -34,33 +30,11 @@ internal static class ReflectionHelper
             {
                 IsEqualFunc = static (left, right) => left is null ? right is null : left.Equals(right);
             }
-
-            var comparableType = typeof(IComparable<>).MakeGenericType(underlyingType);
-            if (comparableType.IsAssignableFrom(underlyingType))
-            {
-                var compareFunc = thisType.GetMethod(isNullableStruct ? nameof(CompareNullable) : nameof(Compare), BindingFlags.Static | BindingFlags.Public)
-                    !.MakeGenericMethod(underlyingType);
-
-                CompareFunc = (Func<T?, T?, int>)Delegate.CreateDelegate(typeof(Func<T?, T?, int>), compareFunc);
-            }
-            else
-            {
-                CompareFunc = static (left, right) => left is null
-                    ? right is null ? 0 : -1
-                    : right is null ? 1 : left.GetHashCode().CompareTo(right.GetHashCode());
-            }
         }
 
     #pragma warning disable CS8604 // Possible null reference argument.
         [Pure] public static bool IsEqual<R>(R? left, R? right) where R : notnull, IEquatable<R>, T => left is null ? right is null : left.Equals(right);
         [Pure] public static bool IsEqualNullable<R>(R? left, R? right) where R : struct, IEquatable<R> => left is null ? right is null : right is not null && left.Value.Equals(right.Value);
-
-        [Pure] public static int Compare<R>(R? left, R? right) where R : notnull, IComparable<R>, T => left is null
-            ? right is null ? 0 : -1
-            : right is null ? 1 : left.CompareTo(right);
-        [Pure] public static int CompareNullable<R>(R? left, R? right) where R : struct, IComparable<R> => left is null
-            ? right is null ? 0 : -1
-            : right is null ? 1 : left.Value.CompareTo(right.Value);
     #pragma warning restore CS8604 // Possible null reference argument.
     }
 }

Railway/Result.cs

@@ -127,7 +127,7 @@ public readonly partial struct Result : IEquatable<Result>
     [Pure] public override bool Equals(object? obj) => obj is Result other && Equals(other);
     [Pure] public bool Equals(Result other)
     {
-        if (State == ResultState.Bottom)
+        if (State == ResultState.Bottom || other.State == ResultState.Bottom)
             throw new ResultNotInitializedException();
 
         return Error == other.Error;
@@ -260,7 +260,7 @@ public readonly struct Result<T> : IEquatable<Result<T>>
     [Pure] public override bool Equals(object? obj) => obj is Result<T> other && Equals(other);
     [Pure] public bool Equals(Result<T> other)
     {
-        if (State == ResultState.Bottom)
+        if (State == ResultState.Bottom || other.State == ResultState.Bottom)
             throw new ResultNotInitializedException();
 
         if (IsSuccess != other.IsSuccess)

Railway/ResultExtensions.cs

@@ -4,9 +4,82 @@ namespace Just.Railway;
 
 public static partial class ResultExtensions
 {
-    #region Match (with fallback)
+    #region Finally
 
-    public static T Match<T>(this in Result<T> result, Func<Error, T> fallback)
+    public static Result Finally(this in Result result, Action action)
+    {
+        switch (result.State)
+        {
+            case ResultState.Success: 
+            case ResultState.Error:
+                action.Invoke();
+                break;
+
+            default: throw new ResultNotInitializedException(nameof(result));
+        }
+
+        return result;
+    }
+
+    public static async Task<Result> Finally(this Task<Result> resultTask, Action action)
+    {
+        var result = await resultTask;
+        switch (result.State)
+        {
+            case ResultState.Success: 
+            case ResultState.Error:
+                action.Invoke();
+                break;
+
+            default: throw new ResultNotInitializedException(nameof(resultTask));
+        }
+
+        return result;
+    }
+    public static async Task<Result> Finally(this Result result, Func<Task> action)
+    {
+        switch (result.State)
+        {
+            case ResultState.Success: 
+            case ResultState.Error:
+                await action.Invoke();
+                break;
+
+            default: throw new ResultNotInitializedException(nameof(result));
+        }
+
+        return result;
+    }
+    public static async Task<Result> Finally(this Task<Result> resultTask, Func<Task> action)
+    {
+        var result = await resultTask;
+        switch (result.State)
+        {
+            case ResultState.Success: 
+            case ResultState.Error:
+                await action.Invoke();
+                break;
+
+            default: throw new ResultNotInitializedException(nameof(resultTask));
+        }
+
+        return result;
+    }
+
+    #endregion
+
+    #region ValueOr
+
+    public static T ValueOr<T>(this in Result<T> result, T fallback)
+    {
+        return result.State switch
+        {
+            ResultState.Success => result.Value,
+            ResultState.Error => fallback,
+            _ => throw new ResultNotInitializedException(nameof(result))
+        };
+    }
+    public static T ValueOr<T>(this in Result<T> result, Func<Error, T> fallback)
     {
         return result.State switch
         {
@@ -16,7 +89,17 @@ public static partial class ResultExtensions
         };
     }
 
-    public static async Task<T> Match<T>(this Result<T> result, Func<Error, Task<T>> fallback)
+    public static async Task<T> ValueOr<T>(this Task<Result<T>> resultTask, T fallback)
+    {
+        var result = await resultTask.ConfigureAwait(false);
+        return result.State switch
+        {
+            ResultState.Success => result.Value,
+            ResultState.Error => fallback,
+            _ => throw new ResultNotInitializedException(nameof(resultTask))
+        };
+    }
+    public static async Task<T> ValueOr<T>(this Result<T> result, Func<Error, Task<T>> fallback)
     {
         return result.State switch
         {
@@ -25,7 +108,7 @@ public static partial class ResultExtensions
             _ => throw new ResultNotInitializedException(nameof(result))
         };
     }
-    public static async Task<T> Match<T>(this Task<Result<T>> resultTask, Func<Error, T> fallback)
+    public static async Task<T> ValueOr<T>(this Task<Result<T>> resultTask, Func<Error, T> fallback)
     {
         var result = await resultTask.ConfigureAwait(false);
         return result.State switch
@@ -35,37 +118,7 @@ public static partial class ResultExtensions
             _ => throw new ResultNotInitializedException(nameof(resultTask))
         };
     }
-    public static async Task<T> Match<T>(this Task<Result<T>> resultTask, Func<Error, Task<T>> fallback)
-    {
-        var result = await resultTask.ConfigureAwait(false);
-        return result.State switch
-        {
-            ResultState.Success => result.Value,
-            ResultState.Error => await fallback(result.Error!).ConfigureAwait(false),
-            _ => throw new ResultNotInitializedException(nameof(resultTask))
-        };
-    }
-
-    public static async ValueTask<T> Match<T>(this Result<T> result, Func<Error, ValueTask<T>> fallback)
-    {
-        return result.State switch
-        {
-            ResultState.Success => result.Value,
-            ResultState.Error => await fallback(result.Error!).ConfigureAwait(false),
-            _ => throw new ResultNotInitializedException(nameof(result))
-        };
-    }
-    public static async ValueTask<T> Match<T>(this ValueTask<Result<T>> resultTask, Func<Error, T> fallback)
-    {
-        var result = await resultTask.ConfigureAwait(false);
-        return result.State switch
-        {
-            ResultState.Success => result.Value,
-            ResultState.Error => fallback(result.Error!),
-            _ => throw new ResultNotInitializedException(nameof(resultTask))
-        };
-    }
-    public static async ValueTask<T> Match<T>(this ValueTask<Result<T>> resultTask, Func<Error, ValueTask<T>> fallback)
+    public static async Task<T> ValueOr<T>(this Task<Result<T>> resultTask, Func<Error, Task<T>> fallback)
     {
         var result = await resultTask.ConfigureAwait(false);
         return result.State switch
@@ -83,79 +136,95 @@ public static partial class ResultExtensions
     public static Result Merge(this IEnumerable<Result> results)
     {
         ImmutableArray<Error>.Builder? errors = null;
-        bool hasErrors = false;
 
-        foreach (var result in results.OrderBy(x => x.State))
+        foreach (var result in results)
         {
             switch (result.State)
             {
-                case ResultState.Error:
-                    hasErrors = true;
-                    errors ??= ImmutableArray.CreateBuilder<Error>();
-                    ManyErrors.AppendSanitized(errors, result.Error!);
+                case ResultState.Success:
                     break;
 
-                case ResultState.Success:
-                    if (hasErrors) goto afterLoop;
+                case ResultState.Error:
+                    errors ??= ImmutableArray.CreateBuilder<Error>();
+                    ManyErrors.AppendSanitized(errors, result.Error!);
                     break;
 
                 default: throw new ResultNotInitializedException(nameof(results));
             }
         }
-        afterLoop:
-        return hasErrors
-            ? new(new ManyErrors(errors!.ToImmutable()))
-            : new(null);
+
+        return errors is null
+            ? new(null)
+            : new(new ManyErrors(errors.ToImmutable()));
     }
     public static async Task<Result> Merge(this IEnumerable<Task<Result>> tasks)
     {
-        var results = await Task.WhenAll(tasks).ConfigureAwait(false);
+        var taskList = tasks.ToArray();
+        var results = new Result[taskList.Length];
+
+        // Wait for all tasks to complete (suppress AggregateException — we'll check each individually)
+        try { await Task.WhenAll(taskList).ConfigureAwait(false); } catch { /* handled per-task below */ }
+
+        for (int i = 0; i < taskList.Length; i++)
+        {
+            var task = taskList[i];
+            results[i] = task.Status switch
+            {
+                TaskStatus.RanToCompletion => task.Result,
+                TaskStatus.Faulted => Result.Failure(task.Exception!),
+                TaskStatus.Canceled => Result.Failure(Error.New("task_canceled", "Task was canceled")),
+                _ => Result.Failure(Error.New("task_unexpected", $"Task in unexpected state: {task.Status}"))
+            };
+        }
+
         return results.Merge();
     }
 
     public static Result<IEnumerable<T>> Merge<T>(this IEnumerable<Result<T>> results)
     {
-        ImmutableList<T>.Builder? values = null;
         ImmutableArray<Error>.Builder? errors = null;
-        bool hasErrors = false;
+        ImmutableArray<T>.Builder? values = null;
 
-        foreach (var result in results.OrderBy(x => x.State))
+        foreach (var result in results)
         {
             switch (result.State)
             {
-                case ResultState.Error:
-                    hasErrors = true;
-                    errors ??= ImmutableArray.CreateBuilder<Error>();
-                    ManyErrors.AppendSanitized(errors, result.Error!);
+                case ResultState.Success:
+                    values ??= ImmutableArray.CreateBuilder<T>();
+                    values.Add(result.Value);
                     break;
 
-                case ResultState.Success:
-                    if (hasErrors) goto afterLoop;
-                    values ??= ImmutableList.CreateBuilder<T>();
-                    values.Add(result.Value);
+                case ResultState.Error:
+                    errors ??= ImmutableArray.CreateBuilder<Error>();
+                    ManyErrors.AppendSanitized(errors, result.Error!);
                     break;
 
                 default: throw new ResultNotInitializedException(nameof(results));
             }
         }
-        afterLoop:
-        return hasErrors
-            ? new(new ManyErrors(errors!.ToImmutable()))
-            : new(values is not null ? values.ToImmutable() : ImmutableList<T>.Empty);
+
+        return errors is null
+            ? new(values?.ToImmutable() ?? Enumerable.Empty<T>())
+            : new(new ManyErrors(errors.ToImmutable()));
     }
     public static async Task<Result<IEnumerable<T>>> Merge<T>(this IEnumerable<Task<Result<T>>> tasks)
     {
-        var taskList = tasks.ToList();
-        var results = new Result<T>[taskList.Count];
+        var taskList = tasks.ToArray();
+        var results = new Result<T>[taskList.Length];
 
-        for (int i = 0; i < taskList.Count; i++)
+        // Wait for all tasks to complete (suppress AggregateException — we'll check each individually)
+        try { await Task.WhenAll(taskList).ConfigureAwait(false); } catch { /* handled per-task below */ }
+
+        for (int i = 0; i < taskList.Length; i++)
         {
-            var task = await Task.WhenAny(taskList);
-            taskList.Remove(task);
-
-            results[i] = task.IsCompletedSuccessfully
-                ? task.Result
-                : task.Exception!;
+            var task = taskList[i];
+            results[i] = task.Status switch
+            {
+                TaskStatus.RanToCompletion => task.Result,
+                TaskStatus.Faulted => Result.Failure<T>(task.Exception!),
+                TaskStatus.Canceled => Result.Failure<T>(Error.New("task_canceled", "Task was canceled")),
+                _ => Result.Failure<T>(Error.New("task_unexpected", $"Task in unexpected state: {task.Status}"))
+            };
         }
 
         return results.Merge();

Railway/Try.cs

@@ -1,5 +1,9 @@
 namespace Just.Railway;
 
+/// <summary>
+/// Result based try/catch
+/// </summary>
+/// <remarks>All extension methods are source generated.</remarks>
 public static partial class Try
 {
 }

Railway/ValueTaskExtensions/ResultValueTaskExtensions.cs

@@ -0,0 +1,98 @@
+namespace Just.Railway.ValueTaskExtensions;
+
+public static partial class ResultValueTaskExtensions
+{
+    #region Finally
+
+    public static async ValueTask<Result> ValueTaskFinally(this ValueTask<Result> resultTask, Action action)
+    {
+        var result = await resultTask;
+        switch (result.State)
+        {
+            case ResultState.Success: 
+            case ResultState.Error:
+                action.Invoke();
+                break;
+
+            default: throw new ResultNotInitializedException(nameof(resultTask));
+        }
+
+        return result;
+    }
+    public static async ValueTask<Result> ValueTaskFinally(this Result result, Func<ValueTask> action)
+    {
+        switch (result.State)
+        {
+            case ResultState.Success: 
+            case ResultState.Error:
+                await action.Invoke();
+                break;
+
+            default: throw new ResultNotInitializedException(nameof(result));
+        }
+
+        return result;
+    }
+    public static async ValueTask<Result> ValueTaskFinally(this ValueTask<Result> resultTask, Func<ValueTask> action)
+    {
+        var result = await resultTask;
+        switch (result.State)
+        {
+            case ResultState.Success: 
+            case ResultState.Error:
+                await action.Invoke();
+                break;
+
+            default: throw new ResultNotInitializedException(nameof(resultTask));
+        }
+
+        return result;
+    }
+ 
+    #endregion
+
+    #region ValueOr
+
+
+    public static async ValueTask<T> ValueTaskValueOr<T>(this ValueTask<Result<T>> resultTask, T fallback)
+    {
+        var result = await resultTask.ConfigureAwait(false);
+        return result.State switch
+        {
+            ResultState.Success => result.Value,
+            ResultState.Error => fallback,
+            _ => throw new ResultNotInitializedException(nameof(resultTask))
+        };
+    }
+    public static async ValueTask<T> ValueTaskValueOr<T>(this Result<T> result, Func<Error, ValueTask<T>> fallback)
+    {
+        return result.State switch
+        {
+            ResultState.Success => result.Value,
+            ResultState.Error => await fallback(result.Error!).ConfigureAwait(false),
+            _ => throw new ResultNotInitializedException(nameof(result))
+        };
+    }
+    public static async ValueTask<T> ValueTaskValueOr<T>(this ValueTask<Result<T>> resultTask, Func<Error, T> fallback)
+    {
+        var result = await resultTask.ConfigureAwait(false);
+        return result.State switch
+        {
+            ResultState.Success => result.Value,
+            ResultState.Error => fallback(result.Error!),
+            _ => throw new ResultNotInitializedException(nameof(resultTask))
+        };
+    }
+    public static async ValueTask<T> ValueTaskValueOr<T>(this ValueTask<Result<T>> resultTask, Func<Error, ValueTask<T>> fallback)
+    {
+        var result = await resultTask.ConfigureAwait(false);
+        return result.State switch
+        {
+            ResultState.Success => result.Value,
+            ResultState.Error => await fallback(result.Error!).ConfigureAwait(false),
+            _ => throw new ResultNotInitializedException(nameof(resultTask))
+        };
+    }
+
+    #endregion
+}

Raliway.Tests/ReflectionHelper/ReflectionHelperTests.cs

@@ -0,0 +1,173 @@
+namespace Raliway.Tests.ReflectionHelper;
+
+// --- Test types ---
+
+file sealed record EquatableRecord(string Name, int Value);
+
+file sealed class NonEquatableClass
+{
+    public string Name { get; }
+    public NonEquatableClass(string name) => Name = name;
+    public override bool Equals(object? obj) => obj is NonEquatableClass other && Name == other.Name;
+    public override int GetHashCode() => Name.GetHashCode();
+}
+
+file readonly struct EquatableStruct : IEquatable<EquatableStruct>
+{
+    public int Value { get; }
+    public EquatableStruct(int value) => Value = value;
+    public bool Equals(EquatableStruct other) => Value == other.Value;
+    public override bool Equals(object? obj) => obj is EquatableStruct s && Equals(s);
+    public override int GetHashCode() => Value;
+}
+
+// --- IsEqual tests ---
+
+public class IsEqual_Tests
+{
+    public class ValueType_IEquatable
+    {
+        [Fact] public void Equal_values() =>
+            Just.Railway.ReflectionHelper.IsEqual(42, 42).ShouldBeTrue();
+
+        [Fact] public void Different_values() =>
+            Just.Railway.ReflectionHelper.IsEqual(42, 43).ShouldBeFalse();
+
+        [Fact] public void Null_args() =>
+            Just.Railway.ReflectionHelper.IsEqual(default(int), default(int)).ShouldBeTrue();
+    }
+
+    public class NullableValueType_IEquatable
+    {
+        [Fact] public void Both_have_same_value() =>
+            Just.Railway.ReflectionHelper.IsEqual<int?>(42, 42).ShouldBeTrue();
+
+        [Fact] public void Different_values() =>
+            Just.Railway.ReflectionHelper.IsEqual<int?>(42, 43).ShouldBeFalse();
+
+        [Fact] public void Both_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<int?>(null, null).ShouldBeTrue();
+
+        [Fact] public void One_null_one_value() =>
+            Just.Railway.ReflectionHelper.IsEqual<int?>(42, null).ShouldBeFalse();
+
+        [Fact] public void Null_and_value_reversed() =>
+            Just.Railway.ReflectionHelper.IsEqual<int?>(null, 42).ShouldBeFalse();
+    }
+
+    public class ReferenceType_IEquatable_String
+    {
+        [Fact] public void Equal_strings() =>
+            Just.Railway.ReflectionHelper.IsEqual("hello", "hello").ShouldBeTrue();
+
+        [Fact] public void Different_strings() =>
+            Just.Railway.ReflectionHelper.IsEqual("hello", "world").ShouldBeFalse();
+
+        [Fact] public void Both_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<string>(null, null).ShouldBeTrue();
+
+        [Fact] public void Left_null_right_value() =>
+            Just.Railway.ReflectionHelper.IsEqual<string>(null, "hello").ShouldBeFalse();
+
+        [Fact] public void Left_value_right_null() =>
+            Just.Railway.ReflectionHelper.IsEqual("hello", null).ShouldBeFalse();
+    }
+
+    public class ReferenceType_IEquatable_Error
+    {
+        [Fact] public void Equal_errors() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                Error.New("type", "msg"),
+                Error.New("type", "msg")
+            ).ShouldBeTrue();
+
+        [Fact] public void Different_errors() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                Error.New("type_a", "msg"),
+                Error.New("type_b", "msg")
+            ).ShouldBeFalse();
+
+        [Fact] public void Both_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<Error>(null, null).ShouldBeTrue();
+
+        [Fact] public void One_null() =>
+            Just.Railway.ReflectionHelper.IsEqual(Error.New("type", "msg"), null).ShouldBeFalse();
+    }
+
+    public class RecordType_IEquatable
+    {
+        [Fact] public void Equal_records() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                new EquatableRecord("a", 1),
+                new EquatableRecord("a", 1)
+            ).ShouldBeTrue();
+
+        [Fact] public void Different_records() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                new EquatableRecord("a", 1),
+                new EquatableRecord("b", 2)
+            ).ShouldBeFalse();
+
+        [Fact] public void Both_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<EquatableRecord>(null, null).ShouldBeTrue();
+    }
+
+    public class NonIEquatable_Fallback
+    {
+        [Fact] public void Equal_by_Equals_override() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                new NonEquatableClass("a"),
+                new NonEquatableClass("a")
+            ).ShouldBeTrue();
+
+        [Fact] public void Not_equal() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                new NonEquatableClass("a"),
+                new NonEquatableClass("b")
+            ).ShouldBeFalse();
+
+        [Fact] public void Both_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<NonEquatableClass>(null, null).ShouldBeTrue();
+
+        [Fact] public void Left_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<NonEquatableClass>(null, new NonEquatableClass("a"))
+                .ShouldBeFalse();
+    }
+
+    public class CustomEquatableStruct
+    {
+        [Fact] public void Equal() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                new EquatableStruct(1),
+                new EquatableStruct(1)
+            ).ShouldBeTrue();
+
+        [Fact] public void Not_equal() =>
+            Just.Railway.ReflectionHelper.IsEqual(
+                new EquatableStruct(1),
+                new EquatableStruct(2)
+            ).ShouldBeFalse();
+    }
+
+    public class CustomNullableEquatableStruct
+    {
+        [Fact] public void Both_have_same_value() =>
+            Just.Railway.ReflectionHelper.IsEqual<EquatableStruct?>(
+                new EquatableStruct(1),
+                new EquatableStruct(1)
+            ).ShouldBeTrue();
+
+        [Fact] public void Different_values() =>
+            Just.Railway.ReflectionHelper.IsEqual<EquatableStruct?>(
+                new EquatableStruct(1),
+                new EquatableStruct(2)
+            ).ShouldBeFalse();
+
+        [Fact] public void Both_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<EquatableStruct?>(null, null).ShouldBeTrue();
+
+        [Fact] public void One_null() =>
+            Just.Railway.ReflectionHelper.IsEqual<EquatableStruct?>(new EquatableStruct(1), null)
+                .ShouldBeFalse();
+    }
+}

Raliway.Tests/Results/Bugs.cs

@@ -0,0 +1,185 @@
+namespace Raliway.Tests.Results;
+
+public class Bugs
+{
+    #region BUG-1: Result.Equals asymmetry
+
+    [Fact]
+    public void Result_Success_ShouldNotEqual_Default()
+    {
+        // default(Result) has State=Bottom — it's uninitialized.
+        // Equals should throw because one operand is Bottom.
+        var success = Result.Success();
+        Result bottom = default;
+
+        // Should throw ResultNotInitializedException, NOT return true
+        Should.Throw<ResultNotInitializedException>(() => success.Equals(bottom));
+    }
+
+    [Fact]
+    public void Result_Default_ShouldNotEqual_Success()
+    {
+        Result bottom = default;
+        var success = Result.Success();
+
+        Should.Throw<ResultNotInitializedException>(() => bottom.Equals(success));
+    }
+
+    [Fact]
+    public void Result_Success_EqualsOperator_WithDefault()
+    {
+        var success = Result.Success();
+        Result bottom = default;
+
+        Should.Throw<ResultNotInitializedException>(() => success == bottom);
+    }
+
+    [Fact]
+    public void Result_Error_Equals_WithBottom_ShouldThrow()
+    {
+        var error = Result.Failure("test");
+        Result bottom = default;
+
+        Should.Throw<ResultNotInitializedException>(() => error.Equals(bottom));
+    }
+
+    [Fact]
+    public void Result_Bottom_Equals_WithSuccess_ShouldThrow()
+    {
+        Result bottom = default;
+        var success = Result.Success();
+
+        Should.Throw<ResultNotInitializedException>(() => bottom.Equals(success));
+    }
+
+    #endregion
+
+    #region BUG-2: Result<T>.Equals asymmetry
+
+    [Fact]
+    public void ResultOfT_Success_ShouldNotEqual_Default()
+    {
+        var success = Result.Success(42);
+        Result<int> bottom = default;
+
+        Should.Throw<ResultNotInitializedException>(() => success.Equals(bottom));
+    }
+
+    [Fact]
+    public void ResultOfT_Error_ShouldNotEqual_Default()
+    {
+        var error = Result.Failure<int>("test");
+        Result<int> bottom = default;
+
+        Should.Throw<ResultNotInitializedException>(() => error.Equals(bottom));
+    }
+
+    [Fact]
+    public void ResultOfT_Default_ShouldNotEqual_Success()
+    {
+        Result<int> bottom = default;
+        var success = Result.Success(42);
+
+        Should.Throw<ResultNotInitializedException>(() => bottom.Equals(success));
+    }
+
+    #endregion
+
+    #region BUG-3: Task.WhenAny Merge — faulted task
+
+    [Fact]
+    public async Task Merge_Tasks_WhenOneFaults_ShouldReturnError_NotThrow()
+    {
+        var tasks = new Task<Result>[]
+        {
+            Task.FromResult(Result.Success()),
+            Task.Run(() =>
+            {
+                throw new InvalidOperationException("boom");
+                #pragma warning disable CS0162 // Unreachable code
+                return Result.Success();
+                #pragma warning restore CS0162
+            }),
+        };
+
+        // Should not throw AggregateException escaping the Result error channel
+        var result = await tasks.Merge();
+
+        result.IsFailure.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task Merge_Tasks_WhenOneIsCanceled_ShouldReturnError_NotThrow()
+    {
+        var cts = new CancellationTokenSource();
+        cts.Cancel();
+        var canceledTask = Task.FromCanceled<Result>(cts.Token);
+
+        var tasks = new Task<Result>[]
+        {
+            Task.FromResult(Result.Success()),
+            canceledTask,
+        };
+
+        // Should not throw — canceled tasks have null Exception
+        var result = await tasks.Merge();
+
+        result.IsFailure.ShouldBeTrue();
+    }
+
+    #endregion
+
+    #region BUG-4: Task.WhenAny Merge<T> — canceled task + O(n²)
+
+    [Fact]
+    public async Task MergeOfT_Tasks_WhenOneIsCanceled_ShouldReturnError_NotThrow()
+    {
+        var cts = new CancellationTokenSource();
+        cts.Cancel();
+        var canceledTask = Task.FromCanceled<Result<int>>(cts.Token);
+
+        var tasks = new Task<Result<int>>[]
+        {
+            Task.FromResult(Result.Success(1)),
+            canceledTask,
+        };
+
+        // Should not crash on canceled task (task.Exception is null → null ref in implicit operator)
+        var result = await tasks.Merge();
+
+        result.IsFailure.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task MergeOfT_Tasks_WhenOneFaults_ShouldReturnError_NotThrow()
+    {
+        var tasks = new Task<Result<int>>[]
+        {
+            Task.FromResult(Result.Success(1)),
+            Task.Run(() =>
+            {
+                throw new InvalidOperationException("boom");
+                #pragma warning disable CS0162 // Unreachable code
+                return Result.Success(2);
+                #pragma warning restore CS0162
+            }),
+        };
+
+        var result = await tasks.Merge();
+
+        result.IsFailure.ShouldBeTrue();
+    }
+
+    #endregion
+
+    #region BUG-5: Error.New null type
+
+    [Fact]
+    public void Error_New_WithNullType_ShouldThrowArgumentNullException()
+    {
+        // Null type should throw immediately at construction, not crash later in CompareTo/IsSimilarTo
+        Should.Throw<ArgumentNullException>(() => Error.New(null!, "some message"));
+    }
+
+    #endregion
+}

Raliway.Tests/Results/GeneralUsage.cs

@@ -37,6 +37,7 @@ public class GeneralUsage
         var result = Result.Success()
             .Append(() => Result.Failure<int>(error))
             .Append("test")
+            .Tap(onSuccess: (i, s) => true.ShouldBeFalse("should not reach this path"))
             .Map((i, s) =>
             {
                 true.ShouldBeFalse("should not reach this path");

Raliway.Tests/TryExtensions/Run.cs

@@ -0,0 +1,558 @@
+namespace Raliway.Tests.TryExtensions;
+
+public class RunTests
+{
+    // ═══════════════════════════════════════════════════════════
+    // Action (void) — sync
+    // ═══════════════════════════════════════════════════════════
+
+    public class Action_Void
+    {
+        [Fact]
+        public void No_args_success()
+        {
+            var result = Try.Run(() => { });
+            result.IsSuccess.ShouldBeTrue();
+        }
+
+        [Fact]
+        public void No_args_exception()
+        {
+            var result = Try.Run(new Action(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+            result.Error!.Type.ShouldBe("System.InvalidOperationException");
+        }
+
+        [Fact]
+        public void One_arg_success()
+        {
+            var captured = 0;
+            var result = Try.Run<int>(x => captured = x, 42);
+            result.IsSuccess.ShouldBeTrue();
+            captured.ShouldBe(42);
+        }
+
+        [Fact]
+        public void One_arg_exception()
+        {
+            var result = Try.Run(new Action<int>(_ => throw new InvalidOperationException("boom")), 42);
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+
+        [Fact]
+        public void Five_args_success()
+        {
+            var captured = "";
+            var result = Try.Run<int, string, bool, double, char>(
+                (a, b, c, d, e) => captured = $"{a}{b}{c}{d}{e}",
+                1, "x", true, 3.14, 'z');
+            result.IsSuccess.ShouldBeTrue();
+            captured.ShouldBe("1xTrue3.14z");
+        }
+
+        [Fact]
+        public void Five_args_exception()
+        {
+            var result = Try.Run(
+                new Action<int, string, bool, double, char>((_, _, _, _, _) => throw new InvalidOperationException("boom")),
+                1, "x", true, 3.14, 'z');
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Func<Result> — sync
+    // ═══════════════════════════════════════════════════════════
+
+    public class Func_Result
+    {
+        [Fact]
+        public void No_args_returns_success()
+        {
+            var result = Try.Run(() => Result.Success());
+            result.IsSuccess.ShouldBeTrue();
+        }
+
+        [Fact]
+        public void No_args_returns_failure()
+        {
+            var error = Error.New("nope");
+            var result = Try.Run(() => Result.Failure(error));
+            result.IsFailure.ShouldBeTrue();
+            result.Error.ShouldBe(error);
+        }
+
+        [Fact]
+        public void No_args_exception_caught()
+        {
+            var result = Try.Run(new Func<Result>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+
+        [Fact]
+        public void One_arg_passes_through()
+        {
+            var result = Try.Run<int>(x => Result.Success(x), 42);
+            result.IsSuccess.ShouldBeTrue();
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Func<T> — sync
+    // ═══════════════════════════════════════════════════════════
+
+    public class Func_T
+    {
+        [Fact]
+        public void No_args_success()
+        {
+            var result = Try.Run(() => 42);
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe(42);
+        }
+
+        [Fact]
+        public void No_args_exception()
+        {
+            var result = Try.Run(new Func<int>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+
+        [Fact]
+        public void One_arg_success()
+        {
+            var result = Try.Run(x => $"val:{x}", 42);
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe("val:42");
+        }
+
+        [Fact]
+        public void One_arg_exception()
+        {
+            var result = Try.Run(new Func<int, string>(_ => throw new InvalidOperationException("boom")), 42);
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+
+        [Fact]
+        public void Null_value_is_preserved()
+        {
+            var result = Try.Run(() => (string?)null);
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBeNull();
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Func<Result<T>> — sync
+    // ═══════════════════════════════════════════════════════════
+
+    public class Func_ResultT
+    {
+        [Fact]
+        public void No_args_returns_success()
+        {
+            var result = Try.Run(() => Result.Success(42));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe(42);
+        }
+
+        [Fact]
+        public void No_args_returns_failure()
+        {
+            var error = Error.New("nope");
+            var result = Try.Run(() => Result.Failure<int>(error));
+            result.IsFailure.ShouldBeTrue();
+            result.Error.ShouldBe(error);
+        }
+
+        [Fact]
+        public void No_args_exception_caught()
+        {
+            var result = Try.Run(new Func<Result<int>>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+
+        [Fact]
+        public void One_arg_passes_through()
+        {
+            var result = Try.Run(x => Result.Success($"val:{x}"), 42);
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe("val:42");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Task async — Action (void)
+    // ═══════════════════════════════════════════════════════════
+
+    public class Task_Action
+    {
+        [Fact]
+        public async Task No_args_success()
+        {
+            var result = await Try.Run(() => Task.CompletedTask);
+            result.IsSuccess.ShouldBeTrue();
+        }
+
+        [Fact]
+        public async Task No_args_exception()
+        {
+            var result = await Try.Run(() => Task.FromException(new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+
+        [Fact]
+        public async Task One_arg_success()
+        {
+            var captured = 0;
+            var result = await Try.Run(x => { captured = x; return Task.CompletedTask; }, 42);
+            result.IsSuccess.ShouldBeTrue();
+            captured.ShouldBe(42);
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Task async — Func<Task<Result>>
+    // ═══════════════════════════════════════════════════════════
+
+    public class Task_Func_Result
+    {
+        [Fact]
+        public async Task No_args_returns_success()
+        {
+            var result = await Try.Run(() => Task.FromResult(Result.Success()));
+            result.IsSuccess.ShouldBeTrue();
+        }
+
+        [Fact]
+        public async Task No_args_returns_failure()
+        {
+            var error = Error.New("nope");
+            var result = await Try.Run(() => Task.FromResult(Result.Failure(error)));
+            result.IsFailure.ShouldBeTrue();
+            result.Error.ShouldBe(error);
+        }
+
+        [Fact]
+        public async Task No_args_exception_caught()
+        {
+            var result = await Try.Run(new Func<Task<Result>>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Task async — Func<Task<T>>
+    // ═══════════════════════════════════════════════════════════
+
+    public class Task_Func_T
+    {
+        [Fact]
+        public async Task No_args_success()
+        {
+            var result = await Try.Run(() => Task.FromResult(42));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe(42);
+        }
+
+        [Fact]
+        public async Task No_args_exception()
+        {
+            var result = await Try.Run(new Func<Task<int>>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Task async — Func<Task<Result<T>>>
+    // ═══════════════════════════════════════════════════════════
+
+    public class Task_Func_ResultT
+    {
+        [Fact]
+        public async Task No_args_returns_success()
+        {
+            var result = await Try.Run(() => Task.FromResult(Result.Success(42)));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe(42);
+        }
+
+        [Fact]
+        public async Task No_args_returns_failure()
+        {
+            var error = Error.New("nope");
+            var result = await Try.Run(() => Task.FromResult(Result.Failure<int>(error)));
+            result.IsFailure.ShouldBeTrue();
+            result.Error.ShouldBe(error);
+        }
+
+        [Fact]
+        public async Task No_args_exception_caught()
+        {
+            var result = await Try.Run(new Func<Task<Result<int>>>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // ValueTask async — Action (void)
+    // ═══════════════════════════════════════════════════════════
+
+    public class ValueTask_Action
+    {
+        [Fact]
+        public async Task No_args_success()
+        {
+            var result = await Try.RunValueTask(() => ValueTask.CompletedTask);
+            result.IsSuccess.ShouldBeTrue();
+        }
+
+        [Fact]
+        public async Task No_args_exception()
+        {
+            var result = await Try.RunValueTask(() => ValueTask.FromException(new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+
+        [Fact]
+        public async Task One_arg_success()
+        {
+            var captured = 0;
+            var result = await Try.RunValueTask(x => { captured = x; return ValueTask.CompletedTask; }, 42);
+            result.IsSuccess.ShouldBeTrue();
+            captured.ShouldBe(42);
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // ValueTask async — Func<ValueTask<Result>>
+    // ═══════════════════════════════════════════════════════════
+
+    public class ValueTask_Func_Result
+    {
+        [Fact]
+        public async Task No_args_returns_success()
+        {
+            var result = await Try.RunValueTask(() => ValueTask.FromResult(Result.Success()));
+            result.IsSuccess.ShouldBeTrue();
+        }
+
+        [Fact]
+        public async Task No_args_returns_failure()
+        {
+            var error = Error.New("nope");
+            var result = await Try.RunValueTask(() => ValueTask.FromResult(Result.Failure(error)));
+            result.IsFailure.ShouldBeTrue();
+            result.Error.ShouldBe(error);
+        }
+
+        [Fact]
+        public async Task No_args_exception_caught()
+        {
+            var result = await Try.RunValueTask(new Func<ValueTask<Result>>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // ValueTask async — Func<ValueTask<T>>
+    // ═══════════════════════════════════════════════════════════
+
+    public class ValueTask_Func_T
+    {
+        [Fact]
+        public async Task No_args_success()
+        {
+            var result = await Try.RunValueTask(() => ValueTask.FromResult(42));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe(42);
+        }
+
+        [Fact]
+        public async Task No_args_exception()
+        {
+            var result = await Try.RunValueTask<int>(() => throw new InvalidOperationException("boom"));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // ValueTask async — Func<ValueTask<Result<T>>>
+    // ═══════════════════════════════════════════════════════════
+
+    public class ValueTask_Func_ResultT
+    {
+        [Fact]
+        public async Task No_args_returns_success()
+        {
+            var result = await Try.RunValueTask(() => ValueTask.FromResult(Result.Success(42)));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe(42);
+        }
+
+        [Fact]
+        public async Task No_args_returns_failure()
+        {
+            var error = Error.New("nope");
+            var result = await Try.RunValueTask(() => ValueTask.FromResult(Result.Failure<int>(error)));
+            result.IsFailure.ShouldBeTrue();
+            result.Error.ShouldBe(error);
+        }
+
+        [Fact]
+        public async Task No_args_exception_caught()
+        {
+            var result = await Try.RunValueTask(new Func<ValueTask<Result<int>>>(() => throw new InvalidOperationException("boom")));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("boom");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // AggregateException unwrapping
+    // ═══════════════════════════════════════════════════════════
+
+    public class AggregateException_Unwrapping
+    {
+        [Fact]
+        public void Single_inner_exception_is_unwrapped()
+        {
+            var result = Try.Run(new Func<int>(() => throw new AggregateException(new InvalidOperationException("inner"))));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Type.ShouldBe("System.InvalidOperationException");
+            result.Error!.Message.ShouldBe("inner");
+        }
+
+        [Fact]
+        public void Multiple_inner_exceptions_become_ManyErrors()
+        {
+            var result = Try.Run(new Func<int>(() => throw new AggregateException(
+                new InvalidOperationException("first"),
+                new ArgumentException("second"))));
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Type.ShouldBe("many_errors");
+            var many = (ManyErrors)result.Error!;
+            many.Count.ShouldBe(2);
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Async exception in task body (not Task.FromException)
+    // ═══════════════════════════════════════════════════════════
+
+    public class Async_Exception_In_Body
+    {
+        [Fact]
+        public async Task Task_throws_in_async_body()
+        {
+            var result = await Try.Run(async () =>
+            {
+                await Task.Yield();
+                throw new InvalidOperationException("async boom");
+            });
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("async boom");
+        }
+
+        [Fact]
+        public async Task ValueTask_throws_in_async_body()
+        {
+            var result = await Try.RunValueTask(async () =>
+            {
+                await Task.Yield();
+                throw new InvalidOperationException("async boom vt");
+            });
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("async boom vt");
+        }
+
+        [Fact]
+        public async Task Task_FuncT_throws_in_async_body()
+        {
+            var result = await Try.Run<int>(async () =>
+            {
+                await Task.Yield();
+                throw new InvalidOperationException("async boom");
+            });
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("async boom");
+        }
+
+        [Fact]
+        public async Task ValueTask_ResultT_throws_in_async_body()
+        {
+            var result = await Try.RunValueTask<int>(async () =>
+            {
+                await Task.Yield();
+                throw new InvalidOperationException("async boom vt");
+            });
+            result.IsFailure.ShouldBeTrue();
+            result.Error!.Message.ShouldBe("async boom vt");
+        }
+    }
+
+    // ═══════════════════════════════════════════════════════════
+    // Edge cases
+    // ═══════════════════════════════════════════════════════════
+
+    public class Edge_Cases
+    {
+        [Fact]
+        public void Reference_type_null_success_value_is_preserved()
+        {
+            var result = Try.Run(() => Result.Success<string?>(null));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBeNull();
+        }
+
+        [Fact]
+        public void Large_ValueTuple_is_preserved()
+        {
+            var result = Try.Run(() => (1, 2, 3, 4, 5));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe((1, 2, 3, 4, 5));
+        }
+
+        [Fact]
+        public async Task Async_large_ValueTuple_is_preserved()
+        {
+            var result = await Try.Run(() => Task.FromResult((1, 2, 3, 4, 5)));
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe((1, 2, 3, 4, 5));
+        }
+
+        [Fact]
+        public void Three_args_all_passed_correctly()
+        {
+            var result = Try.Run(
+                (a, b, c) => $"{a}-{b}-{c}",
+                1, "two", true);
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe("1-two-True");
+        }
+
+        [Fact]
+        public async Task Task_with_three_args()
+        {
+            var result = await Try.Run(
+                (a, b, c) => Task.FromResult($"{a}-{b}-{c}"),
+                1, "two", true);
+            result.IsSuccess.ShouldBeTrue();
+            result.Value.ShouldBe("1-two-True");
+        }
+    }
+}