add AOT mode checks to prevent unsupported reflection usage and suppress AOT warnings in reflection classes (#3239)

Author: thomhurst

TUnit.Core/DynamicTestBuilderContext.cs

@@ -1,3 +1,5 @@
+using System.Diagnostics.CodeAnalysis;
+
 namespace TUnit.Core;
 
 /// <summary>
@@ -20,6 +22,7 @@ public DynamicTestBuilderContext(string filePath, int lineNumber)
 
     public IReadOnlyList<AbstractDynamicTest> Tests => _tests.AsReadOnly();
 
+    [RequiresDynamicCode("Adding dynamic tests requires reflection which is not supported in native AOT scenarios.")]
     public void AddTest(AbstractDynamicTest test)
     {
         // Set creator location if the test implements IDynamicTestCreatorLocation
@@ -28,7 +31,7 @@ public void AddTest(AbstractDynamicTest test)
             testWithLocation.CreatorFilePath = FilePath;
             testWithLocation.CreatorLineNumber = LineNumber;
         }
-        
+
         _tests.Add(test);
     }
 }

TUnit.Core/Extensions/TestContextExtensions.cs

@@ -24,6 +24,7 @@ public static string GetClassTypeName(this TestContext context)
         return $"{context.TestDetails.ClassType.Name}({string.Join(", ", context.TestDetails.TestClassArguments.Select(a => ArgumentFormatter.Format(a, context.ArgumentDisplayFormatters)))})";
     }
 
+    [RequiresDynamicCode("Adding dynamic tests requires reflection which is not supported in native AOT scenarios.")]
     public static async Task AddDynamicTest<[DynamicallyAccessedMembers(
         DynamicallyAccessedMemberTypes.PublicConstructors
         | DynamicallyAccessedMemberTypes.NonPublicConstructors

TUnit.Core/Interfaces/ITestRegistry.cs

@@ -14,13 +14,14 @@ public interface ITestRegistry
     /// <param name="context">The current test context</param>
     /// <param name="dynamicTest">The dynamic test instance to add</param>
     /// <returns>A task that completes when the test has been queued for execution</returns>
+    [RequiresDynamicCode("Adding dynamic tests requires runtime compilation and reflection which are not supported in native AOT scenarios.")]
     Task AddDynamicTest<[DynamicallyAccessedMembers(
         DynamicallyAccessedMemberTypes.PublicConstructors
         | DynamicallyAccessedMemberTypes.NonPublicConstructors
         | DynamicallyAccessedMemberTypes.PublicProperties
         | DynamicallyAccessedMemberTypes.PublicMethods
         | DynamicallyAccessedMemberTypes.NonPublicMethods
         | DynamicallyAccessedMemberTypes.PublicFields
-        | DynamicallyAccessedMemberTypes.NonPublicFields)] T>(TestContext context, DynamicTest<T> dynamicTest) 
+        | DynamicallyAccessedMemberTypes.NonPublicFields)] T>(TestContext context, DynamicTest<T> dynamicTest)
         where T : class;
 }

TUnit.Core/PropertyInjection/Initialization/Strategies/ReflectionPropertyStrategy.cs

@@ -1,4 +1,5 @@
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 using TUnit.Core.DataSources;
 using TUnit.Core.Initialization;
@@ -33,6 +34,13 @@ public bool CanHandle(PropertyInitializationContext context)
     [UnconditionalSuppressMessage("Trimming", "IL2072", Justification = "Reflection mode support")]
     public async Task InitializePropertyAsync(PropertyInitializationContext context)
     {
+#if NET
+        if (!RuntimeFeature.IsDynamicCodeSupported)
+        {
+            throw new Exception("Using TUnit Reflection mechanisms isn't supported in AOT mode");
+        }
+#endif
+
         if (context.PropertyInfo == null || context.DataSource == null)
         {
             return;
@@ -58,4 +66,4 @@ public async Task InitializePropertyAsync(PropertyInitializationContext context)
         PropertyTrackingService.AddToTestContext(context, resolvedValue);
     }
 
-}
+}

TUnit.Engine/Building/Collectors/AotTestDataCollector.cs

@@ -76,6 +76,8 @@ private async IAsyncEnumerable<TestMetadata> CollectDynamicTestsStreaming(
         }
     }
 
+    [UnconditionalSuppressMessage("AOT", "IL3050:Calling members annotated with 'RequiresDynamicCodeAttribute' may break functionality when AOT compiling.",
+        Justification = "Dynamic tests are opt-in and users are warned via RequiresDynamicCode on the method they call")]
     private async IAsyncEnumerable<TestMetadata> ConvertDynamicTestToMetadataStreaming(
         AbstractDynamicTest abstractDynamicTest,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
@@ -92,6 +94,7 @@ private async IAsyncEnumerable<TestMetadata> ConvertDynamicTestToMetadataStreami
         }
     }
 
+    [System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Dynamic tests require runtime compilation of lambda expressions and are not supported in native AOT scenarios.")]
     private Task<TestMetadata> CreateMetadataFromDynamicDiscoveryResult(DynamicDiscoveryResult result)
     {
         if (result.TestClassType == null || result.TestMethod == null)
@@ -144,6 +147,7 @@ private Task<TestMetadata> CreateMetadataFromDynamicDiscoveryResult(DynamicDisco
         });
     }
 
+    [System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Dynamic test instance creation requires Activator.CreateInstance and MakeGenericType which are not supported in native AOT scenarios.")]
     [UnconditionalSuppressMessage("Trimming",
         "IL2070:'this' argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicConstructors' in call to 'System.Type.GetConstructors()'",
         Justification = "AOT mode uses source-generated factories")]
@@ -187,6 +191,7 @@ private Task<TestMetadata> CreateMetadataFromDynamicDiscoveryResult(DynamicDisco
         };
     }
 
+    [System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Dynamic test invocation requires LambdaExpression.Compile() which is not supported in native AOT scenarios.")]
     private static Func<object, object?[], Task> CreateAotDynamicTestInvoker(DynamicDiscoveryResult result)
     {
         return async (instance, args) =>

TUnit.Engine/Building/ReflectionMetadataBuilder.cs

@@ -1,4 +1,5 @@
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
 using TUnit.Core;
 
 namespace TUnit.Engine.Building;

TUnit.Engine/Building/TestDataCollectorFactory.cs

@@ -23,8 +23,6 @@ internal static class TestDataCollectorFactory
     /// Creates a test data collector based on the specified or detected mode.
     /// Source generation mode is preferred for AOT compatibility.
     /// </summary>
-    [UnconditionalSuppressMessage("Trimming", "IL2026:Using member 'TUnit.Engine.Discovery.ReflectionTestDataCollector.ReflectionTestDataCollector()' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code", Justification = "Reflection mode is explicitly chosen and cannot support trimming")]
-    [UnconditionalSuppressMessage("AOT", "IL3050:Using member 'TUnit.Engine.Discovery.ReflectionTestDataCollector.ReflectionTestDataCollector()' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling", Justification = "Reflection mode is explicitly chosen and cannot support AOT")]
     public static ITestDataCollector Create(bool? useSourceGeneration = null, Assembly[]? assembliesToScan = null)
     {
         var isSourceGenerationEnabled = useSourceGeneration ?? SourceRegistrar.IsEnabled;
@@ -43,8 +41,6 @@ public static ITestDataCollector Create(bool? useSourceGeneration = null, Assemb
     /// Attempts AOT mode first, falls back to reflection if no source-generated tests found.
     /// This provides automatic mode selection for optimal performance and compatibility.
     /// </summary>
-    [UnconditionalSuppressMessage("Trimming", "IL2026:Using member 'TUnit.Engine.Discovery.ReflectionTestDataCollector.ReflectionTestDataCollector()' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code", Justification = "Reflection mode is a fallback and cannot support trimming")]
-    [UnconditionalSuppressMessage("AOT", "IL3050:Using member 'TUnit.Engine.Discovery.ReflectionTestDataCollector.ReflectionTestDataCollector()' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling", Justification = "Reflection mode is a fallback and cannot support AOT")]
     public static async Task<ITestDataCollector> CreateAutoDetectAsync(string testSessionId, Assembly[]? assembliesToScan = null)
     {
         // Try AOT mode first (check if any tests were registered)

TUnit.Engine/Discovery/ReflectionAttributeExtractor.cs

@@ -1,6 +1,7 @@
 using System.Collections.Concurrent;
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using TUnit.Core;
 
 namespace TUnit.Engine.Discovery;
@@ -59,8 +60,15 @@ public override int GetHashCode()
     /// </summary>
     public static T? GetAttribute<T>(Type testClass, MethodInfo? testMethod = null) where T : Attribute
     {
+#if NET
+        if (!RuntimeFeature.IsDynamicCodeSupported)
+        {
+            throw new Exception("Using TUnit Reflection mechanisms isn't supported in AOT mode");
+        }
+#endif
+
         var cacheKey = new AttributeCacheKey(testClass, testMethod, typeof(T));
-        
+
         return (T?)_attributeCache.GetOrAdd(cacheKey, key =>
         {
             // Original lookup logic preserved
@@ -88,6 +96,13 @@ public override int GetHashCode()
     /// </summary>
     public static IEnumerable<T> GetAttributes<T>(Type testClass, MethodInfo? testMethod = null) where T : Attribute
     {
+#if NET
+        if (!RuntimeFeature.IsDynamicCodeSupported)
+        {
+            throw new Exception("Using TUnit Reflection mechanisms isn't supported in AOT mode");
+        }
+#endif
+
         var attributes = new List<T>();
 
         attributes.AddRange(testClass.Assembly.GetCustomAttributes<T>());
@@ -104,7 +119,7 @@ public static IEnumerable<T> GetAttributes<T>(Type testClass, MethodInfo? testMe
     public static string[] ExtractCategories(Type testClass, MethodInfo testMethod)
     {
         var categories = new HashSet<string>();
-        
+
         foreach (var attr in GetAttributes<CategoryAttribute>(testClass, testMethod))
         {
             categories.Add(attr.Category);
@@ -128,7 +143,7 @@ public static bool CanRunInParallel(Type testClass, MethodInfo testMethod)
     public static TestDependency[] ExtractDependencies(Type testClass, MethodInfo testMethod)
     {
         var dependencies = new List<TestDependency>();
-        
+
         foreach (var attr in GetAttributes<DependsOnAttribute>(testClass, testMethod))
         {
             dependencies.Add(attr.ToTestDependency());
@@ -155,13 +170,13 @@ public static IDataSourceAttribute[] ExtractDataSources(ICustomAttributeProvider
     public static Attribute[] GetAllAttributes(Type testClass, MethodInfo testMethod)
     {
         var attributes = new List<Attribute>();
-        
+
         // Add in reverse order of precedence so method attributes come first
         // This ensures ScopedAttributeFilter will keep method-level attributes over class/assembly
         attributes.AddRange(testMethod.GetCustomAttributes());
         attributes.AddRange(testClass.GetCustomAttributes());
         attributes.AddRange(testClass.Assembly.GetCustomAttributes());
-        
+
         return attributes.ToArray();
     }
 
@@ -193,4 +208,4 @@ public static PropertyDataSource[] ExtractPropertyDataSources([DynamicallyAccess
 
         return propertyDataSources.ToArray();
     }
-}
+}

TUnit.Engine/Discovery/ReflectionGenericTypeResolver.cs

@@ -1,20 +1,34 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using TUnit.Core;
 
 namespace TUnit.Engine.Discovery;
 
 /// <summary>
 /// Handles generic type resolution and instantiation for reflection-based test discovery
 /// </summary>
-[RequiresUnreferencedCode("Reflection-based generic type resolution requires unreferenced code")]
+[UnconditionalSuppressMessage("Trimming", "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code", Justification = "Reflection mode cannot support trimming")]
+[UnconditionalSuppressMessage("Trimming", "IL2055:Call to 'System.Type.MakeGenericType' can not be statically analyzed", Justification = "Reflection mode requires dynamic access")]
+[UnconditionalSuppressMessage("Trimming", "IL2065:Value passed to implicit 'this' parameter of method can not be statically determined and may not meet 'DynamicallyAccessedMembersAttribute' requirements", Justification = "Reflection mode requires dynamic access")]
+[UnconditionalSuppressMessage("Trimming", "IL2067:Target parameter does not satisfy annotation requirements", Justification = "Reflection mode requires dynamic access")]
+[UnconditionalSuppressMessage("Trimming", "IL2070:Target method does not satisfy annotation requirements", Justification = "Reflection mode requires dynamic access")]
+[UnconditionalSuppressMessage("Trimming", "IL2075:'this' argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicMethods' in call to 'System.Type.GetMethods(BindingFlags)'", Justification = "Reflection mode requires dynamic access")]
+[UnconditionalSuppressMessage("AOT", "IL3050:Calling members annotated with 'RequiresDynamicCodeAttribute' may break functionality when AOT compiling.", Justification = "Reflection mode cannot support AOT")]
 internal static class ReflectionGenericTypeResolver
 {
     /// <summary>
     /// Determines generic type arguments from data row values
     /// </summary>
     public static Type[]? DetermineGenericTypeArguments(Type genericTypeDefinition, object?[] dataRow)
     {
+#if NET
+        if (!RuntimeFeature.IsDynamicCodeSupported)
+        {
+            throw new Exception("Using TUnit Reflection mechanisms isn't supported in AOT mode");
+        }
+#endif
+
         var genericParameters = genericTypeDefinition.GetGenericArguments();
 
         // If no data row or empty data, can't determine types
@@ -68,9 +82,6 @@ internal static class ReflectionGenericTypeResolver
     /// <summary>
     /// Extracts generic type information including constraints
     /// </summary>
-    [UnconditionalSuppressMessage("Trimming",
-        "IL2065:Value passed to implicit 'this' parameter of method 'System.Type.GetInterfaces()' can not be statically determined and may not meet 'DynamicallyAccessedMembersAttribute' requirements",
-        Justification = "Reflection mode requires dynamic access")]
     public static GenericTypeInfo? ExtractGenericTypeInfo(Type testClass)
     {
         if (!testClass.IsGenericTypeDefinition)
@@ -106,9 +117,6 @@ internal static class ReflectionGenericTypeResolver
     /// <summary>
     /// Extracts generic method information including parameter positions
     /// </summary>
-    [UnconditionalSuppressMessage("Trimming",
-        "IL2065:Value passed to implicit 'this' parameter of method 'System.Type.GetInterfaces()' can not be statically determined and may not meet 'DynamicallyAccessedMembersAttribute' requirements",
-        Justification = "Reflection mode requires dynamic access")]
     public static GenericMethodInfo? ExtractGenericMethodInfo(MethodInfo method)
     {
         if (!method.IsGenericMethodDefinition)
@@ -157,10 +165,6 @@ internal static class ReflectionGenericTypeResolver
     /// <summary>
     /// Creates a concrete type from a generic type definition and validates the type arguments
     /// </summary>
-    [UnconditionalSuppressMessage("Trimming", "IL2055:Call to 'System.Type.MakeGenericType' can not be statically analyzed",
-        Justification = "Reflection mode requires dynamic access")]
-    [UnconditionalSuppressMessage("AOT", "IL3050:Calling members annotated with 'RequiresDynamicCodeAttribute' may break functionality when AOT compiling.",
-        Justification = "Reflection mode cannot support AOT")]
     public static Type CreateConcreteType(Type genericTypeDefinition, Type[] typeArguments)
     {
         var genericParams = genericTypeDefinition.GetGenericArguments();
@@ -174,4 +178,4 @@ public static Type CreateConcreteType(Type genericTypeDefinition, Type[] typeArg
 
         return genericTypeDefinition.MakeGenericType(typeArguments);
     }
-}
+}