From 82b62b0a41f4254d4ec7f03777e0e626d2682dfc Mon Sep 17 00:00:00 2001
From: Tom Longhurst <30480171+thomhurst@users.noreply.github.com>
Date: Thu, 28 May 2026 18:14:33 +0100
Subject: [PATCH 1/2] perf: replace LINQ Any with foreach in
 TestGenericTypeResolver (#6044)

Avoid delegate and IEnumerator allocations on the generic test resolution hot path during discovery.
---
 TUnit.Engine/Services/TestGenericTypeResolver.cs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/TUnit.Engine/Services/TestGenericTypeResolver.cs b/TUnit.Engine/Services/TestGenericTypeResolver.cs
index f6a5e216dc..ba99c96557 100644
--- a/TUnit.Engine/Services/TestGenericTypeResolver.cs
+++ b/TUnit.Engine/Services/TestGenericTypeResolver.cs
@@ -133,7 +133,19 @@ private static Type[] ResolveMethodGenericArguments(
     {
         // Handle the case where some parameter types are Object (placeholders for generic parameters)
         // This happens when data sources provide untyped data or when we have mixed generic/non-generic parameters
-        if (parameterTypes.Any(t => t == typeof(object)) && methodArguments.Length > 0)
+        var hasObjectParameter = false;
+        if (methodArguments.Length > 0)
+        {
+            foreach (var parameterType in parameterTypes)
+            {
+                if (parameterType == typeof(object))
+                {
+                    hasObjectParameter = true;
+                    break;
+                }
+            }
+        }
+        if (hasObjectParameter)
         {
             // Check if this is a simple generic method with one type parameter and mixed parameters
             if (genericMethodInfo.ParameterNames.Length == 1 && parameterTypes.Length >= 1)

From 6b2c7a7401ef3b8b2440058fdfe385b0da4297ee Mon Sep 17 00:00:00 2001
From: Tom Longhurst <30480171+thomhurst@users.noreply.github.com>
Date: Thu, 28 May 2026 18:33:21 +0100
Subject: [PATCH 2/2] perf: also drop LINQ All in TestGenericTypeResolver
 fallback

Convert the second `parameterTypes.All(t => t == typeof(object))`
call to a foreach with a hoisted `methodArguments.Length > 0` guard,
mirroring the prior `Any` substitution. Eliminates the remaining
per-call delegate and enumerator allocation on this hot path. Per
reviewer feedback on PR #6072.
---
 TUnit.Engine/Services/TestGenericTypeResolver.cs | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/TUnit.Engine/Services/TestGenericTypeResolver.cs b/TUnit.Engine/Services/TestGenericTypeResolver.cs
index ba99c96557..6c4d26e578 100644
--- a/TUnit.Engine/Services/TestGenericTypeResolver.cs
+++ b/TUnit.Engine/Services/TestGenericTypeResolver.cs
@@ -205,7 +205,20 @@ private static Type[] ResolveMethodGenericArguments(
         
         // Handle the case where all parameter types are Object
         // This happens when data sources provide untyped data
-        if (parameterTypes.All(t => t == typeof(object)) && methodArguments.Length > 0)
+        var allParametersAreObject = methodArguments.Length > 0;
+        if (allParametersAreObject)
+        {
+            foreach (var t in parameterTypes)
+            {
+                if (t != typeof(object))
+                {
+                    allParametersAreObject = false;
+                    break;
+                }
+            }
+        }
+
+        if (allParametersAreObject)
         {
             // For the AggregateBy test case with 3 generic parameters
             if (genericMethodInfo.ParameterNames.Length == 3 &&