fix: assign TestDetails before TestContext is published to ClassHookContext.Tests

TUnit.Core/ContextProvider.cs

@@ -8,7 +8,7 @@ namespace TUnit.Core;
 /// <summary>
 /// Builder for creating and managing the context hierarchy with proper parent-child relationships and singleton behavior
 /// </summary>
-public class ContextProvider(IServiceProvider serviceProvider, string testSessionId, string? testFilter) : IContextProvider
+internal class ContextProvider(IServiceProvider serviceProvider, string testSessionId, string? testFilter) : IContextProvider
 {
     private readonly ConcurrentDictionary<Assembly, AssemblyHookContext> _assemblyContexts = new();
     private readonly ConcurrentDictionary<Type, ClassHookContext> _classContexts = new();
@@ -81,15 +81,20 @@ public ClassHookContext GetOrCreateClassContext(
     /// Creates a test context with proper parent hierarchy
     /// </summary>
     public TestContext CreateTestContext(
-        string testName,
         [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.PublicProperties | DynamicallyAccessedMemberTypes.PublicMethods)]
         Type classType,
         TestBuilderContext testBuilderContext,
+        TestDetails testDetails,
         CancellationToken cancellationToken)
     {
         var classContext = GetOrCreateClassContext(classType);
 
-        var testContext = new TestContext(testName, serviceProvider, classContext, testBuilderContext, cancellationToken);
+        var testContext = new TestContext(testDetails.TestName, serviceProvider, classContext, testBuilderContext, cancellationToken)
+        {
+            // Must be assigned before AddTest publishes the context via ClassHookContext.Tests —
+            // AfterEvery(Class) hooks can iterate Tests while sibling dynamic tests are still being built.
+            TestDetails = testDetails,
+        };
 
         classContext.AddTest(testContext);
 

TUnit.Core/Services/IContextProvider.cs

@@ -6,7 +6,7 @@ namespace TUnit.Core.Services;
 /// <summary>
 /// Interface for building and managing context hierarchies
 /// </summary>
-public interface IContextProvider
+internal interface IContextProvider
 {
     /// <summary>
     /// Gets or creates the discovery context
@@ -36,12 +36,14 @@ ClassHookContext GetOrCreateClassContext(
         Type classType);
 
     /// <summary>
-    /// Creates a test context
+    /// Creates a test context. <paramref name="testDetails"/> is assigned before the context
+    /// becomes observable via <see cref="ClassHookContext.Tests"/> so hooks never see a
+    /// partially-built context.
     /// </summary>
     TestContext CreateTestContext(
-        string testName,
         [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.PublicProperties | DynamicallyAccessedMemberTypes.PublicMethods)]
         Type classType,
         TestBuilderContext testBuilderContext,
+        TestDetails testDetails,
         CancellationToken cancellationToken);
 }

TUnit.Engine/Building/TestBuilder.cs

@@ -1078,13 +1078,11 @@ private async ValueTask<TestContext> CreateTestContextAsync(string testId, TestM
         };
 
         var context = _contextProvider.CreateTestContext(
-            metadata.TestName,
             metadata.TestClassType,
             testBuilderContext,
+            testDetails,
             CancellationToken.None);
 
-        context.Metadata.TestDetails = testDetails;
-
         return context;
     }
 
@@ -1174,16 +1172,14 @@ private async Task<Attribute[]> InitializeAttributesAsync(Attribute[] attributes
     private TestContext CreateFailedTestContext(TestMetadata metadata, TestDetails testDetails)
     {
         var context = _contextProvider.CreateTestContext(
-            metadata.TestName,
             metadata.TestClassType,
             new TestBuilderContext
             {
                 TestMetadata = metadata.MethodMetadata
             },
+            testDetails,
             CancellationToken.None);
 
-        context.Metadata.TestDetails = testDetails;
-
         return context;
     }
 

TUnit.Engine/Building/TestBuilderPipeline.cs

@@ -265,14 +265,11 @@ private async Task<AbstractExecutableTest[]> GenerateDynamicTests(TestMetadata m
             var testBuilderContext = CreateTestBuilderContext(metadata);
 
             var context = _contextProvider.CreateTestContext(
-                metadata.TestName,
                 metadata.TestClassType,
                 testBuilderContext,
+                testDetails,
                 CancellationToken.None);
 
-            // Set the TestDetails on the context
-            context.Metadata.TestDetails = testDetails;
-
             // Set custom display name for dynamic tests if specified
             if (dynamicTestMetadata?.DisplayName != null)
             {
@@ -392,14 +389,11 @@ private async IAsyncEnumerable<AbstractExecutableTest> BuildTestsFromSingleMetad
                     };
 
                     var context = _contextProvider.CreateTestContext(
-                        resolvedMetadata.TestName,
                         resolvedMetadata.TestClassType,
                         CreateTestBuilderContext(resolvedMetadata),
+                        testDetails,
                         CancellationToken.None);
 
-                    // Set the TestDetails on the context
-                    context.Metadata.TestDetails = testDetails;
-
                     // Set custom display name for dynamic tests if specified
                     if (dynamicMetadata.DisplayName != null)
                     {
@@ -473,13 +467,11 @@ private AbstractExecutableTest CreateFailedTestForDataGenerationError(TestMetada
         };
 
         var context = _contextProvider.CreateTestContext(
-            metadata.TestName,
             metadata.TestClassType,
             CreateTestBuilderContext(metadata),
+            testDetails,
             CancellationToken.None);
 
-        context.Metadata.TestDetails = testDetails;
-
         var now = DateTimeOffset.UtcNow;
 
         return new FailedExecutableTest(exception)
@@ -528,13 +520,11 @@ private AbstractExecutableTest CreateFailedTestForGenericResolutionError(TestMet
         };
 
         var context = _contextProvider.CreateTestContext(
-            metadata.TestName,
             metadata.TestClassType,
             CreateTestBuilderContext(metadata),
+            testDetails,
             CancellationToken.None);
 
-        context.Metadata.TestDetails = testDetails;
-
         var now = DateTimeOffset.UtcNow;
 
         return new FailedExecutableTest(exception)

TUnit.PublicAPI/Tests.Core_Library_Has_No_API_Changes.DotNet10_0.verified.txt

@@ -423,18 +423,6 @@ namespace
         public virtual string GetStandardOutput() { }
         public void RestoreExecutionContext() { }
     }
-    public class ContextProvider : .
-    {
-        public ContextProvider( serviceProvider, string testSessionId, string? testFilter) { }
-        public .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        public .GlobalContext GlobalContext { get; }
-        public .TestDiscoveryContext TestDiscoveryContext { get; }
-        public .TestSessionContext TestSessionContext { get; }
-        public .TestContext CreateTestContext(string testName, [.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken) { }
-        public .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly) { }
-        [.("Trimming", "IL2111", Justification="Type parameter is annotated at the method boundary.")]
-        public .ClassHookContext GetOrCreateClassContext([.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType) { }
-    }
     public class CultureExecutor : .DedicatedThreadExecutor
     {
         public CultureExecutor(.CultureInfo cultureInfo) { }
@@ -2898,15 +2886,6 @@ namespace .Services
         public [] ResolveGenericClassArguments([.(..PublicConstructors)]  genericTypeDefinition, object?[] constructorArguments) { }
         public [] ResolveGenericMethodArguments(.MethodInfo genericMethodDefinition, object?[] runtimeArguments) { }
     }
-    public interface IContextProvider
-    {
-        .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        .TestDiscoveryContext TestDiscoveryContext { get; }
-        .TestSessionContext TestSessionContext { get; }
-        .TestContext CreateTestContext(string testName, [.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken);
-        .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly);
-        .ClassHookContext GetOrCreateClassContext([.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType);
-    }
     public static class ModeDetector
     {
         public static bool IsSourceGenerationAvailable { get; }

TUnit.PublicAPI/Tests.Core_Library_Has_No_API_Changes.DotNet8_0.verified.txt

@@ -423,18 +423,6 @@ namespace
         public virtual string GetStandardOutput() { }
         public void RestoreExecutionContext() { }
     }
-    public class ContextProvider : .
-    {
-        public ContextProvider( serviceProvider, string testSessionId, string? testFilter) { }
-        public .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        public .GlobalContext GlobalContext { get; }
-        public .TestDiscoveryContext TestDiscoveryContext { get; }
-        public .TestSessionContext TestSessionContext { get; }
-        public .TestContext CreateTestContext(string testName, [.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken) { }
-        public .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly) { }
-        [.("Trimming", "IL2111", Justification="Type parameter is annotated at the method boundary.")]
-        public .ClassHookContext GetOrCreateClassContext([.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType) { }
-    }
     public class CultureExecutor : .DedicatedThreadExecutor
     {
         public CultureExecutor(.CultureInfo cultureInfo) { }
@@ -2898,15 +2886,6 @@ namespace .Services
         public [] ResolveGenericClassArguments([.(..PublicConstructors)]  genericTypeDefinition, object?[] constructorArguments) { }
         public [] ResolveGenericMethodArguments(.MethodInfo genericMethodDefinition, object?[] runtimeArguments) { }
     }
-    public interface IContextProvider
-    {
-        .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        .TestDiscoveryContext TestDiscoveryContext { get; }
-        .TestSessionContext TestSessionContext { get; }
-        .TestContext CreateTestContext(string testName, [.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken);
-        .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly);
-        .ClassHookContext GetOrCreateClassContext([.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType);
-    }
     public static class ModeDetector
     {
         public static bool IsSourceGenerationAvailable { get; }

TUnit.PublicAPI/Tests.Core_Library_Has_No_API_Changes.DotNet9_0.verified.txt

@@ -423,18 +423,6 @@ namespace
         public virtual string GetStandardOutput() { }
         public void RestoreExecutionContext() { }
     }
-    public class ContextProvider : .
-    {
-        public ContextProvider( serviceProvider, string testSessionId, string? testFilter) { }
-        public .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        public .GlobalContext GlobalContext { get; }
-        public .TestDiscoveryContext TestDiscoveryContext { get; }
-        public .TestSessionContext TestSessionContext { get; }
-        public .TestContext CreateTestContext(string testName, [.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken) { }
-        public .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly) { }
-        [.("Trimming", "IL2111", Justification="Type parameter is annotated at the method boundary.")]
-        public .ClassHookContext GetOrCreateClassContext([.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType) { }
-    }
     public class CultureExecutor : .DedicatedThreadExecutor
     {
         public CultureExecutor(.CultureInfo cultureInfo) { }
@@ -2898,15 +2886,6 @@ namespace .Services
         public [] ResolveGenericClassArguments([.(..PublicConstructors)]  genericTypeDefinition, object?[] constructorArguments) { }
         public [] ResolveGenericMethodArguments(.MethodInfo genericMethodDefinition, object?[] runtimeArguments) { }
     }
-    public interface IContextProvider
-    {
-        .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        .TestDiscoveryContext TestDiscoveryContext { get; }
-        .TestSessionContext TestSessionContext { get; }
-        .TestContext CreateTestContext(string testName, [.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken);
-        .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly);
-        .ClassHookContext GetOrCreateClassContext([.(..None | ..PublicParameterlessConstructor | ..PublicConstructors | ..PublicMethods | ..PublicProperties)]  classType);
-    }
     public static class ModeDetector
     {
         public static bool IsSourceGenerationAvailable { get; }

TUnit.PublicAPI/Tests.Core_Library_Has_No_API_Changes.Net4_7.verified.txt

@@ -403,17 +403,6 @@ namespace
         public virtual string GetStandardOutput() { }
         public void RestoreExecutionContext() { }
     }
-    public class ContextProvider : .
-    {
-        public ContextProvider( serviceProvider, string testSessionId, string? testFilter) { }
-        public .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        public .GlobalContext GlobalContext { get; }
-        public .TestDiscoveryContext TestDiscoveryContext { get; }
-        public .TestSessionContext TestSessionContext { get; }
-        public .TestContext CreateTestContext(string testName,  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken) { }
-        public .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly) { }
-        public .ClassHookContext GetOrCreateClassContext( classType) { }
-    }
     public class CultureExecutor : .DedicatedThreadExecutor
     {
         public CultureExecutor(.CultureInfo cultureInfo) { }
@@ -2819,15 +2808,6 @@ namespace .Services
         public [] ResolveGenericClassArguments( genericTypeDefinition, object?[] constructorArguments) { }
         public [] ResolveGenericMethodArguments(.MethodInfo genericMethodDefinition, object?[] runtimeArguments) { }
     }
-    public interface IContextProvider
-    {
-        .BeforeTestDiscoveryContext BeforeTestDiscoveryContext { get; }
-        .TestDiscoveryContext TestDiscoveryContext { get; }
-        .TestSessionContext TestSessionContext { get; }
-        .TestContext CreateTestContext(string testName,  classType, .TestBuilderContext testBuilderContext, .CancellationToken cancellationToken);
-        .AssemblyHookContext GetOrCreateAssemblyContext(.Assembly assembly);
-        .ClassHookContext GetOrCreateClassContext( classType);
-    }
     public static class ModeDetector
     {
         public static bool IsSourceGenerationAvailable { get; }

TUnit.UnitTests/ContextProviderTests.cs

@@ -0,0 +1,76 @@
+namespace TUnit.UnitTests;
+
+/// <summary>
+/// Regression tests for https://github.com/thomhurst/TUnit/issues/6180 —
+/// a partially-built <see cref="TestContext"/> (with <c>TestDetails == null</c>) must never
+/// be observable via <see cref="ClassHookContext.Tests"/>, otherwise AfterEvery(Class) hooks
+/// running concurrently with dynamic test registration NRE on <c>test.Metadata.TestDetails</c>.
+/// </summary>
+public class ContextProviderTests
+{
+    [Test]
+    public async Task CreateTestContext_PublishesContextWithTestDetailsAlreadyAssigned()
+    {
+        var provider = new ContextProvider(new EmptyServiceProvider(), Guid.NewGuid().ToString(), testFilter: null);
+
+        var classMetadata = new ClassMetadata
+        {
+            Type = typeof(DummyTestClass),
+            TypeInfo = new ConcreteType(typeof(DummyTestClass)),
+            Name = nameof(DummyTestClass),
+            Namespace = typeof(DummyTestClass).Namespace ?? string.Empty,
+            Assembly = new AssemblyMetadata
+            {
+                Name = typeof(DummyTestClass).Assembly.GetName().Name ?? string.Empty
+            },
+            Parent = null,
+            Parameters = [],
+            Properties = []
+        };
+
+        var methodMetadata = MethodMetadataFactory.Create(
+            nameof(DummyTestClass.SomeTest),
+            typeof(DummyTestClass),
+            typeof(Task),
+            classMetadata);
+
+        var testDetails = new TestDetails([])
+        {
+            TestId = "Test:0",
+            TestName = nameof(DummyTestClass.SomeTest),
+            ClassType = typeof(DummyTestClass),
+            MethodName = nameof(DummyTestClass.SomeTest),
+            ClassInstance = PlaceholderInstance.Instance,
+            TestMethodArguments = [],
+            TestClassArguments = [],
+            MethodMetadata = methodMetadata,
+            ReturnType = typeof(Task),
+            AttributesByType = new Dictionary<Type, IReadOnlyList<Attribute>>()
+        };
+
+        var context = provider.CreateTestContext(
+            typeof(DummyTestClass),
+            new TestBuilderContext { TestMetadata = methodMetadata },
+            testDetails,
+            CancellationToken.None);
+
+        var classContext = provider.GetOrCreateClassContext(typeof(DummyTestClass));
+        var publishedContext = classContext.Tests.Single();
+
+        // The contract callers (and AfterEvery(Class) hooks) rely on: by the time a context is
+        // visible in ClassHookContext.Tests, its TestDetails is set — no post-hoc assignment.
+        await Assert.That(publishedContext).IsSameReferenceAs(context);
+        await Assert.That(publishedContext.TestDetails).IsNotNull();
+        await Assert.That(publishedContext.Metadata.TestDetails).IsSameReferenceAs(testDetails);
+    }
+
+    private sealed class DummyTestClass
+    {
+        public Task SomeTest() => Task.CompletedTask;
+    }
+
+    private sealed class EmptyServiceProvider : IServiceProvider
+    {
+        public object? GetService(Type serviceType) => null;
+    }
+}

TUnit.UnitTests/SessionActivityLifecycleTests.cs

@@ -309,12 +309,12 @@ public ClassHookContext GetOrCreateClassContext(
             throw new NotSupportedException();
 
         public TestContext CreateTestContext(
-            string testName,
             [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors |
                                         DynamicallyAccessedMemberTypes.PublicProperties |
                                         DynamicallyAccessedMemberTypes.PublicMethods)]
             Type classType,
             TestBuilderContext testBuilderContext,
+            TestDetails testDetails,
             CancellationToken cancellationToken) =>
             throw new NotSupportedException();
     }