Add Source metadata support to Mediator and Consumer descriptions

src/Mocha/src/Mocha.Mediator/DependencyInjection/MediatorBuilder.cs

@@ -204,7 +204,8 @@ public MediatorRuntime Build(IServiceProvider applicationServices)
                 config.Kind,
                 MediatorUrn.Message(serviceName, messageName),
                 messageName,
-                config.ResponseType is { } responseType ? MediatorDescriptionHelpers.GetTypeName(responseType) : null));
+                config.ResponseType is { } responseType ? MediatorDescriptionHelpers.GetTypeName(responseType) : null,
+                config.Source));
 
             var terminal = config.Delegate ?? BuildPipelineViaReflection(config);
 

src/Mocha/src/Mocha.Mediator/Descriptions/MediatorHandlerDescription.cs

@@ -9,10 +9,12 @@ namespace Mocha.Mediator;
 /// <param name="MessageId">The URN identity of the message the handler handles.</param>
 /// <param name="MessageName">The readable message type name.</param>
 /// <param name="ResponseTypeName">The readable response type name, or <c>null</c> for void commands and notifications.</param>
+/// <param name="Source">Source metadata captured from the handler declaration, or <c>null</c> when not provided.</param>
 public sealed record MediatorHandlerDescription(
     string Id,
     string Name,
     MediatorHandlerKind Kind,
     string MessageId,
     string MessageName,
-    string? ResponseTypeName);
+    string? ResponseTypeName,
+    SourceMetadata? Source);

src/Mocha/src/Mocha/Consumers/Consumer.cs

@@ -197,7 +197,8 @@ public virtual ConsumerDescription Describe()
             DescriptionHelpers.GetTypeName(Identity),
             Identity.FullName,
             null,
-            false);
+            false,
+            Configuration?.Source);
     }
 
     /// <summary>

src/Mocha/src/Mocha/Consumers/Implementations/BatchConsumer.cs

@@ -155,7 +155,14 @@ private async Task ProcessBatchAsync(MessageBatch<TEvent> batch, CancellationTok
 
     public override ConsumerDescription Describe()
     {
-        return new ConsumerDescription(Urn, Name, DescriptionHelpers.GetTypeName(Identity), Identity.FullName, null, true);
+        return new ConsumerDescription(
+            Urn,
+            Name,
+            DescriptionHelpers.GetTypeName(Identity),
+            Identity.FullName,
+            null,
+            true,
+            Configuration?.Source);
     }
 
     public override async ValueTask DisposeAsync()

src/Mocha/src/Mocha/Descriptions/ConsumerDescription.cs

@@ -9,10 +9,12 @@ namespace Mocha;
 /// <param name="IdentityTypeFullName">The fully qualified type name of the handler, or <c>null</c> if unavailable.</param>
 /// <param name="SagaName">The name of the associated saga, or <c>null</c> if this consumer is not part of a saga.</param>
 /// <param name="IsBatch">Whether this consumer processes messages in batches.</param>
+/// <param name="Source">Source metadata captured from the consumer declaration, or <c>null</c> when not provided.</param>
 public sealed record ConsumerDescription(
     string Id,
     string Name,
     string IdentityType,
     string? IdentityTypeFullName,
     string? SagaName,
-    bool IsBatch);
+    bool IsBatch,
+    SourceMetadata? Source);

src/Mocha/src/Mocha/Descriptions/MessageTypeDescription.cs

@@ -11,6 +11,7 @@ namespace Mocha;
 /// <param name="IsInternal">Whether this message type is internal to the bus and not exposed to user code.</param>
 /// <param name="DefaultContentType">The default serialization content type, or <c>null</c> if using the bus default.</param>
 /// <param name="EnclosedMessageIdentities">The identities of message types enclosed by this type, or <c>null</c> if none.</param>
+/// <param name="Source">Source metadata captured from the message type declaration, or <c>null</c> when not provided.</param>
 public sealed record MessageTypeDescription(
     string Id,
     string Identity,
@@ -19,4 +20,5 @@ public sealed record MessageTypeDescription(
     bool IsInterface,
     bool IsInternal,
     string? DefaultContentType,
-    IReadOnlyList<string>? EnclosedMessageIdentities);
+    IReadOnlyList<string>? EnclosedMessageIdentities,
+    SourceMetadata? Source);

src/Mocha/src/Mocha/Descriptions/SagaDescription.cs

@@ -9,10 +9,12 @@ namespace Mocha;
 /// <param name="StateTypeFullName">The fully qualified type name of the saga state, or <c>null</c> if unavailable.</param>
 /// <param name="ConsumerName">The name of the consumer that drives this saga.</param>
 /// <param name="States">The descriptions of all states in this saga.</param>
+/// <param name="Source">Source metadata captured from the saga declaration, or <c>null</c> when not provided.</param>
 public sealed record SagaDescription(
     string Id,
     string Name,
     string StateType,
     string? StateTypeFullName,
     string ConsumerName,
-    IReadOnlyList<SagaStateDescription> States);
+    IReadOnlyList<SagaStateDescription> States,
+    SourceMetadata? Source);

src/Mocha/src/Mocha/MessageTypes/MessageType.cs

@@ -234,7 +234,8 @@ public MessageTypeDescription Describe()
             IsInterface,
             IsInternal,
             DefaultContentType?.Value,
-            EnclosedMessageIdentities.IsDefaultOrEmpty ? null : EnclosedMessageIdentities);
+            EnclosedMessageIdentities.IsDefaultOrEmpty ? null : EnclosedMessageIdentities,
+            Source);
     }
 
     [RequiresUnreferencedCode("Uses GetInterfaces and BaseType traversal which may reference trimmed types.")]

src/Mocha/src/Mocha/Sagas/Saga.cs

@@ -156,7 +156,8 @@ state.Response is not null
             DescriptionHelpers.GetTypeName(StateType),
             StateType.FullName,
             Consumer.Name,
-            states);
+            states,
+            Configuration?.Source);
     }
 
     /// <summary>

src/Mocha/src/Mocha/Sagas/SagaEventListener.cs

@@ -79,7 +79,8 @@ public override ConsumerDescription Describe()
             DescriptionHelpers.GetTypeName(Identity),
             Identity.FullName,
             saga.Name,
-            false);
+            false,
+            Configuration?.Source ?? saga.Configuration?.Source);
     }
 
     /// <inheritdoc />

src/Mocha/test/Mocha.Mediator.Tests/MediatorDescriptionTests.cs

@@ -24,4 +24,30 @@ public void Describe_Should_ReturnMediatorDescription_When_HandlersRegistered()
         // assert
         description.MatchSnapshot();
     }
+
+    [Fact]
+    public void Describe_Should_ReturnSource_When_HandlerConfigurationHasSource()
+    {
+        // arrange
+        var source = new SourceMetadata
+        {
+            Assembly = "Mocha.Mediator.Tests",
+            RepositoryUrl = "https://github.com/example/mocha",
+            Commit = "abc123",
+            XmlDocumentation = "<summary>Manual query handler.</summary>",
+            DeclarationLocation = new DeclarationLocation("ManualQueryHandler.cs", 1, 1, 5, 2)
+        };
+        var services = new ServiceCollection();
+        services.AddMediator()
+            .ConfigureOptions(o => o.ServiceName = "orders")
+            .AddHandler<ManualQueryHandler>(d => d.Extend().Configuration.Source = source);
+        using var provider = services.BuildServiceProvider();
+
+        // act
+        var description = provider.GetRequiredService<MediatorRuntime>().Describe();
+
+        // assert
+        var handler = description.Handlers.Single(h => h.Name == nameof(ManualQueryHandler));
+        Assert.Same(source, handler.Source);
+    }
 }

src/Mocha/test/Mocha.Mediator.Tests/__snapshots__/MediatorDescriptionTests.Describe_Should_ReturnMediatorDescription_When_HandlersRegistered.snap

@@ -8,31 +8,35 @@
       "Kind": "CommandResponse",
       "MessageId": "urn:mocha:svc:orders:mediator:message:ManualCommand",
       "MessageName": "ManualCommand",
-      "ResponseTypeName": "ManualResponse"
+      "ResponseTypeName": "ManualResponse",
+      "Source": null
     },
     {
       "Id": "urn:mocha:svc:orders:mediator:handler:ManualNotificationHandler1",
       "Name": "ManualNotificationHandler1",
       "Kind": "Notification",
       "MessageId": "urn:mocha:svc:orders:mediator:message:ManualNotification",
       "MessageName": "ManualNotification",
-      "ResponseTypeName": null
+      "ResponseTypeName": null,
+      "Source": null
     },
     {
       "Id": "urn:mocha:svc:orders:mediator:handler:ManualQueryHandler",
       "Name": "ManualQueryHandler",
       "Kind": "Query",
       "MessageId": "urn:mocha:svc:orders:mediator:message:ManualQuery",
       "MessageName": "ManualQuery",
-      "ResponseTypeName": "ManualResponse"
+      "ResponseTypeName": "ManualResponse",
+      "Source": null
     },
     {
       "Id": "urn:mocha:svc:orders:mediator:handler:ManualVoidCommandHandler",
       "Name": "ManualVoidCommandHandler",
       "Kind": "Command",
       "MessageId": "urn:mocha:svc:orders:mediator:message:ManualVoidCommand",
       "MessageName": "ManualVoidCommand",
-      "ResponseTypeName": null
+      "ResponseTypeName": null,
+      "Source": null
     }
   ]
 }

src/Mocha/test/Mocha.Sagas.Tests/SagaInitializationTests.cs

@@ -268,6 +268,70 @@ public void Describe_Should_UseStateAndTransitionUrns_When_SagaInitialized()
         Assert.Equal(startedCancel.Urn, startedCancelDescription.Id);
     }
 
+    [Fact]
+    public void Describe_Should_ReturnSource_When_SagaConfigurationHasSource()
+    {
+        // Arrange
+        var source = new SourceMetadata
+        {
+            Assembly = "Mocha.Sagas.Tests",
+            RepositoryUrl = "https://github.com/example/mocha",
+            Commit = "abc123",
+            XmlDocumentation = "<summary>Test saga.</summary>",
+            DeclarationLocation = new DeclarationLocation("TestSaga.cs", 1, 1, 10, 2)
+        };
+        var saga = CreateInitializedSagaWithSource(source);
+
+        // Act
+        var description = saga.Describe();
+
+        // Assert
+        Assert.Same(source, description.Source);
+    }
+
+    [Fact]
+    public void ConsumerDescribe_Should_FallBackToSagaSource_When_ConsumerConfigurationHasNoSource()
+    {
+        // Arrange - the saga consumer never sets Source on its own ConsumerConfiguration, so
+        // Consumer.Describe() must fall back to the saga's own Source.
+        var source = new SourceMetadata
+        {
+            Assembly = "Mocha.Sagas.Tests",
+            RepositoryUrl = "https://github.com/example/mocha",
+            Commit = "abc123",
+            XmlDocumentation = "<summary>Test saga.</summary>",
+            DeclarationLocation = new DeclarationLocation("TestSaga.cs", 1, 1, 10, 2)
+        };
+        var saga = CreateInitializedSagaWithSource(source);
+
+        // Act
+        var description = saga.Consumer.Describe();
+
+        // Assert
+        Assert.Same(source, description.Source);
+    }
+
+    private Saga<TestState> CreateInitializedSagaWithSource(SourceMetadata source)
+    {
+        var saga =
+            Saga.Create<TestState>(descriptor =>
+            {
+                descriptor.Extend().Configuration.Source = source;
+
+                descriptor
+                    .Initially()
+                    .OnEvent<StartEvent>()
+                    .TransitionTo("Started")
+                    .StateFactory(s => new TestState(Guid.NewGuid(), "Started"));
+                descriptor.During("Started").OnEvent<TriggerEvent>().TransitionTo("Success");
+                descriptor.Finally("Success");
+            });
+
+        saga.Initialize(_context);
+
+        return saga;
+    }
+
     private Saga<TestState> CreateInitializedSagaWithCancelTransitions()
     {
         var saga =

src/Mocha/test/Mocha.Tests/Consumers/ConsumerBehaviorTests.cs

@@ -22,6 +22,29 @@ public void Describe_Should_ReturnConsumerDescription_When_EventHandlerRegistere
         description.MatchSnapshot();
     }
 
+    [Fact]
+    public void Describe_Should_ReturnSource_When_ConsumerConfigurationHasSource()
+    {
+        // arrange
+        var source = new SourceMetadata
+        {
+            Assembly = "Mocha.Tests",
+            RepositoryUrl = "https://github.com/example/mocha",
+            Commit = "abc123",
+            XmlDocumentation = "<summary>Handles order created events.</summary>",
+            DeclarationLocation = new DeclarationLocation("OrderCreatedHandler.cs", 1, 1, 5, 2)
+        };
+        var runtime = CreateRuntime(
+            b => b.AddEventHandler<OrderCreatedHandler>(d => d.Extend().Configuration.Source = source));
+        var consumer = runtime.Consumers.First(c => c.Name == nameof(OrderCreatedHandler));
+
+        // act
+        var description = consumer.Describe();
+
+        // assert
+        Assert.Same(source, description.Source);
+    }
+
     [Fact]
     public async Task ProcessAsync_Should_ThrowInvalidOperationException_When_ContextIsNotConsumeContext()
     {

src/Mocha/test/Mocha.Tests/Consumers/__snapshots__/ConsumerBehaviorTests.Describe_Should_ReturnConsumerDescription_When_EventHandlerRegistered.snap

@@ -4,5 +4,6 @@
   "IdentityType": "OrderCreatedHandler",
   "IdentityTypeFullName": "Mocha.Tests.Consumers.ConsumerBehaviorTests+OrderCreatedHandler",
   "SagaName": null,
-  "IsBatch": false
+  "IsBatch": false,
+  "Source": null
 }

src/Mocha/test/Mocha.Tests/MessageTypes/MessageTypeTests.cs

@@ -17,6 +17,33 @@ public void EventHandler_Should_RegisterMessageType_When_AddingEventHandler()
         Assert.Equal(typeof(OrderCreated), messageType.RuntimeType);
     }
 
+    [Fact]
+    public void Describe_Should_ReturnSource_When_MessageTypeConfigurationHasSource()
+    {
+        // arrange
+        var source = new SourceMetadata
+        {
+            Assembly = "Mocha.Tests",
+            RepositoryUrl = "https://github.com/example/mocha",
+            Commit = "abc123",
+            XmlDocumentation = "<summary>Raised when an order is created.</summary>",
+            DeclarationLocation = new DeclarationLocation("OrderCreated.cs", 1, 1, 3, 2)
+        };
+        var runtime = CreateRuntime(b =>
+        {
+            b.AddEventHandler<OrderCreatedHandler>();
+            b.AddMessage<OrderCreated>(d => d.Extend().Configuration.Source = source);
+        });
+        var messageType = runtime.Messages.GetMessageType(typeof(OrderCreated));
+        Assert.NotNull(messageType);
+
+        // act
+        var description = messageType.Describe();
+
+        // assert
+        Assert.Same(source, description.Source);
+    }
+
     [Fact]
     public void EventHandlerMessageType_Should_HaveUrnIdentity_When_Registered()
     {