From 31cad400d43d281a485808f58edf603e9739c177 Mon Sep 17 00:00:00 2001
From: Tom Longhurst <30480171+thomhurst@users.noreply.github.com>
Date: Thu, 28 May 2026 18:14:23 +0100
Subject: [PATCH] perf(engine): avoid closure allocation in
 AfterHookPairTracker.GetOrCreateAfterAssemblyTask (#6041)

Add a lock-free TryGetValue fast path before GetOrAdd so cache hits no
longer allocate a closure capturing taskFactory. Mirrors the existing
pattern in GetOrCreateAfterClassTask.
---
 TUnit.Engine/Services/AfterHookPairTracker.cs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/TUnit.Engine/Services/AfterHookPairTracker.cs b/TUnit.Engine/Services/AfterHookPairTracker.cs
index 2adc97a56b..9f25689412 100644
--- a/TUnit.Engine/Services/AfterHookPairTracker.cs
+++ b/TUnit.Engine/Services/AfterHookPairTracker.cs
@@ -155,6 +155,12 @@ public ValueTask<List<Exception>> GetOrCreateAfterTestSessionTask(Func<ValueTask
     /// </summary>
     public ValueTask<List<Exception>> GetOrCreateAfterAssemblyTask(Assembly assembly, Func<Assembly, ValueTask<List<Exception>>> taskFactory)
     {
+        // Lock-free fast path avoids allocating a closure on the common cache-hit case.
+        if (_afterAssemblyTasks.TryGetValue(assembly, out var existingTask))
+        {
+            return new ValueTask<List<Exception>>(existingTask);
+        }
+
         var task = _afterAssemblyTasks.GetOrAdd(assembly, a => taskFactory(a).AsTask());
         return new ValueTask<List<Exception>>(task);
     }