feat(Microservice.Api): add support for transactional outbox messages

- Added a new using directive for `ES.FX.Contracts.TransactionalOutbox` in `Program.cs`.
- Configured the application to exclude publishing of `IOutboxMessage`.
- Updated `MessageTypeEntityNameFormatter` class to include parameters for fault fallback and fault format.
- Enhanced the `FormatEntityName<TMessage>` method to handle formatting of Fault message types.

playground/Playground.Microservice.Api.Host/Program.cs

@@ -1,4 +1,5 @@
 using Asp.Versioning;
+using ES.FX.Contracts.TransactionalOutbox;
 using ES.FX.Hosting.Lifetime;
 using ES.FX.Ignite.Asp.Versioning.Hosting;
 using ES.FX.Ignite.Azure.Data.Tables.Hosting;
@@ -141,6 +142,8 @@
             cfg.Publish<INotification>(p => p.Exclude = true);
             cfg.Publish<IRequest>(p => p.Exclude = true);
             cfg.Publish<IBaseRequest>(p => p.Exclude = true);
+            cfg.Publish<IOutboxMessage>(p => p.Exclude = true);
+
 
             cfg.MessageTopology.SetEntityNameFormatter(new AggregatePrefixEntityNameFormatter(
                 new MessageTypeEntityNameFormatter(cfg.MessageTopology.EntityNameFormatter),

src/ES.FX.MassTransit/Formatters/MessageTypeEntityNameFormatter.cs

@@ -1,5 +1,6 @@
 using ES.FX.Contracts.Messaging;
 using MassTransit;
+using MassTransit.Internals;
 
 namespace ES.FX.MassTransit.Formatters;
 
@@ -8,9 +9,39 @@ namespace ES.FX.MassTransit.Formatters;
 ///     <see cref="IEntityNameFormatter" /> as the base formatter
 /// </summary>
 /// <param name="entityNameFormatter"><see cref="IEndpointNameFormatter" /> to use as the base formatter</param>
-public class MessageTypeEntityNameFormatter(IEntityNameFormatter entityNameFormatter) : IEntityNameFormatter
+/// <param name="faultFallbackToMessageType">
+///     When set to true, the <see cref="MessageTypeAttribute" /> and
+///     <param name="faultFormat"></param>
+///     will be used to determine the <see cref="Fault" /> message name
+/// </param>
+/// <param name="faultFormat">
+///     The format to use for the fault message type if <see cref="MessageTypeAttribute" /> is set
+///     but <see cref="FaultMessageTypeAttribute" /> is not set
+/// </param>
+public class MessageTypeEntityNameFormatter(
+    IEntityNameFormatter entityNameFormatter,
+    bool faultFallbackToMessageType = true,
+    string faultFormat = "{0}_fault") : IEntityNameFormatter
 {
-    public string FormatEntityName<TMessage>() =>
-        MessageTypeAttribute.TypeFor(typeof(TMessage)) ??
-        entityNameFormatter.FormatEntityName<TMessage>();
+    public string FormatEntityName<TMessage>()
+    {
+        if (typeof(TMessage).ClosesType(typeof(Fault<>), out Type[] messageTypes))
+        {
+            var type = FaultMessageTypeAttribute.TypeFor(messageTypes.First());
+            if (type is not null) return type;
+
+            if (faultFallbackToMessageType)
+            {
+                type = MessageTypeAttribute.TypeFor(messageTypes.First());
+                if (type is not null) return string.Format(faultFormat, type);
+            }
+        }
+        else
+        {
+            var type = MessageTypeAttribute.TypeFor(typeof(TMessage));
+            if (type is not null) return type;
+        }
+
+        return entityNameFormatter.FormatEntityName<TMessage>();
+    }
 }