From fbde4234d4554ff0a8953162ae4fb0fad8c5a961 Mon Sep 17 00:00:00 2001
From: Timothy Makkison <timmakkison@gmail.com>
Date: Wed, 21 Jan 2026 22:21:32 +0000
Subject: [PATCH] perf: reuse no data array and empty task

---
 TUnit.Core/Attributes/TestData/NoDataSource.cs | 3 ++-
 TUnit.Engine/Building/TestBuilder.cs           | 4 +++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/TUnit.Core/Attributes/TestData/NoDataSource.cs b/TUnit.Core/Attributes/TestData/NoDataSource.cs
index d61c2de0ff..87052cb3bc 100644
--- a/TUnit.Core/Attributes/TestData/NoDataSource.cs
+++ b/TUnit.Core/Attributes/TestData/NoDataSource.cs
@@ -2,6 +2,7 @@
 
 internal class NoDataSource : IDataSourceAttribute
 {
+    private static readonly Task<object?[]?> _emptyRowTask = Task.FromResult<object?[]?>([]);
     public static readonly NoDataSource Instance = new();
 
     /// <inheritdoc />
@@ -9,7 +10,7 @@ internal class NoDataSource : IDataSourceAttribute
 
     public async IAsyncEnumerable<Func<Task<object?[]?>>> GetDataRowsAsync(DataGeneratorMetadata dataGeneratorMetadata)
     {
-        yield return () => Task.FromResult<object?[]?>([]);
+        yield return static () => _emptyRowTask;
         await default(ValueTask);
     }
 }
diff --git a/TUnit.Engine/Building/TestBuilder.cs b/TUnit.Engine/Building/TestBuilder.cs
index 04ca0732b1..19daa42c95 100644
--- a/TUnit.Engine/Building/TestBuilder.cs
+++ b/TUnit.Engine/Building/TestBuilder.cs
@@ -812,11 +812,13 @@ private static Type[] TryInferClassGenericsFromDataSources(TestMetadata metadata
         return resolvedTypes;
     }
 
+    private static readonly IDataSourceAttribute[] _dataSourceArray = [NoDataSource.Instance];
+
     private async Task<IDataSourceAttribute[]> GetDataSourcesAsync(IDataSourceAttribute[] dataSources)
     {
         if (dataSources.Length == 0)
         {
-            return [NoDataSource.Instance];
+            return _dataSourceArray;
         }
 
         // Inject properties into data sources during discovery (IAsyncInitializer deferred to execution)