More fixes to void/result constraints

Sample/Handlers/ErrorRequestHandler.cs

@@ -2,6 +2,7 @@
 
 namespace Sample.Handlers;
 
+
 [RegisterHandler]
 public class ErrorRequestHandler : IRequestHandler<ErrorRequest>
 {

Sample/MauiProgram.cs

@@ -42,11 +42,10 @@ public static MauiApp CreateMauiApp()
             .UseBlazor()
             .AddUserNotificationExceptionMiddleware(new UserExceptionRequestMiddlewareConfig
             {
-                ErrorConfirm = "Error",
+                ErrorConfirm = "OK",
+                ErrorTitle = "OOOPS",
                 ErrorMessage = "You did something wrong",
-#if DEBUG
-                ShowFullException = true
-#endif
+                ShowFullException = false
             })
         );
         builder.Services.AddDiscoveredMediatorHandlersFromSample();

src/Shiny.Mediator.Maui/Middleware/CacheRequestMiddleware.cs

@@ -6,7 +6,7 @@ namespace Shiny.Mediator.Middleware;
 public class CacheRequestMiddleware<TRequest, TResult>(
     IConnectivity connectivity, 
     IFileSystem fileSystem
-) : IRequestMiddleware<TRequest, TResult> where TRequest : IRequest<TResult> 
+) : IRequestMiddleware<TRequest, TResult> 
     // IRequestHandler<FlushAllCacheRequest>, 
     // IRequestHandler<FlushCacheItemRequest>
 { 

src/Shiny.Mediator.Maui/Middleware/TimedLoggingRequestMiddleware.cs

@@ -5,7 +5,7 @@
 namespace Shiny.Mediator.Middleware;
 
 
-public class TimedLoggingRequestMiddleware<TRequest, TResult>(ILogger<TRequest> logger) : IRequestMiddleware<TRequest, TResult> where TRequest : IRequest<TResult>
+public class TimedLoggingRequestMiddleware<TRequest, TResult>(ILogger<TRequest> logger) : IRequestMiddleware<TRequest, TResult>
 {
     public async Task<TResult> Process(TRequest request, RequestHandlerDelegate<TResult> next, IRequestHandler requestHandler, CancellationToken cancellationToken)
     {

src/Shiny.Mediator.Maui/Middleware/UserNotificationExceptionRequestMiddleware.cs

@@ -3,7 +3,7 @@
 namespace Shiny.Mediator.Middleware;
 
 
-public class UserExceptionRequestMiddleware<TRequest, TResult>(ILogger<TRequest> logger, UserExceptionRequestMiddlewareConfig config) : IRequestMiddleware<TRequest, TResult> where TRequest : IRequest<TResult>
+public class UserExceptionRequestMiddleware<TRequest, TResult>(ILogger<TRequest> logger, UserExceptionRequestMiddlewareConfig config) : IRequestMiddleware<TRequest, TResult>
 {
     public async Task<TResult> Process(TRequest request, RequestHandlerDelegate<TResult> next, IRequestHandler requestHandler, CancellationToken cancellationToken)
     {

src/Shiny.Mediator/Impl/DefaultRequestSender.cs

@@ -40,25 +40,14 @@ public async Task Handle(IServiceProvider services, TRequest request, Cancellati
         if (requestHandler == null)
             throw new InvalidOperationException("No request handler found for " + request.GetType().FullName);
 
-        var handler = new RequestHandlerDelegate<Unit>(async () =>
+        var handlerExec = new RequestHandlerDelegate<Unit>(async () =>
         {
             await requestHandler.Handle(request, cancellationToken).ConfigureAwait(false);
             return Unit.Value;
         });
 
-        await services
-            .GetServices<IRequestMiddleware<TRequest, Unit>>()
-            .Reverse()
-            .Aggregate(
-                handler, 
-                (next, middleware) => () => middleware.Process(
-                    request, 
-                    next, 
-                    requestHandler,
-                    cancellationToken
-                )
-            )
-            .Invoke()
+        await RequestExecutor
+            .Execute(services, request, requestHandler, handlerExec, cancellationToken)
             .ConfigureAwait(false);
     }
 }
@@ -71,14 +60,34 @@ public async Task<TResult> Handle(IServiceProvider services, TRequest request, C
         if (requestHandler == null)
             throw new InvalidOperationException("No request handler found for " + request.GetType().FullName);
 
-        var handler = new RequestHandlerDelegate<TResult>(()
+        var handlerExec = new RequestHandlerDelegate<TResult>(()
             => requestHandler.Handle(request, cancellationToken));
+
+        var result = await RequestExecutor
+            .Execute(services, request, requestHandler, handlerExec, cancellationToken)
+            .ConfigureAwait(false);
+
+        return result;
+    }
+}
+
+
+static class RequestExecutor
+{
+    public static async Task<TResult> Execute<TRequest, TResult>(
+        IServiceProvider services, 
+        TRequest request, 
+        IRequestHandler requestHandler,
+        RequestHandlerDelegate<TResult> handlerExec,
+        CancellationToken cancellationToken
+    )
+    {
+        var middleware = services.GetServices<IRequestMiddleware<TRequest, TResult>>();
 
-        var result = await services
-            .GetServices<IRequestMiddleware<TRequest, TResult>>()
+        var result = await middleware
             .Reverse()
             .Aggregate(
-                handler, 
+                handlerExec, 
                 (next, middleware) => () => middleware.Process(
                     request, 
                     next,