Add the ability to create a separate DI scope

Author: javiercn

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerExtensions.cs

@@ -47,6 +47,25 @@ public static IApplicationBuilder UseExceptionHandler(this IApplicationBuilder a
         });
     }
 
+    /// <summary>
+    /// Adds a middleware to the pipeline that will catch exceptions, log them, reset the request path, and re-execute the request.
+    /// The request will not be re-executed if the response has already started.
+    /// </summary>
+    /// <param name="app">The <see cref="IApplicationBuilder"/>.</param>
+    /// <param name="errorHandlingPath">The <see cref="string"/> path to the endpoint that will handle the exception.</param>
+    /// <param name="newScope">Whether or not to create a new <see cref="IServiceProvider"/> scope.</param>
+    /// <returns></returns>
+    public static IApplicationBuilder UseExceptionHandler(this IApplicationBuilder app, string errorHandlingPath, bool newScope)
+    {
+        ArgumentNullException.ThrowIfNull(app);
+
+        return app.UseExceptionHandler(new ExceptionHandlerOptions
+        {
+            ExceptionHandlingPath = new PathString(errorHandlingPath),
+            UseNewServiceResolutionScope = newScope
+        });
+    }
+
     /// <summary>
     /// Adds a middleware to the pipeline that will catch exceptions, log them, and re-execute the request in an alternate pipeline.
     /// The request will not be re-executed if the response has already started.

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerMiddlewareImpl.cs

@@ -10,6 +10,7 @@
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.AspNetCore.Diagnostics;
 
@@ -70,6 +71,7 @@ public ExceptionHandlerMiddlewareImpl(
     public Task Invoke(HttpContext context)
     {
         ExceptionDispatchInfo edi;
+
         try
         {
             var task = _next(context);
@@ -141,8 +143,16 @@ private async Task HandleException(HttpContext context, ExceptionDispatchInfo ed
         {
             context.Request.Path = _options.ExceptionHandlingPath;
         }
+        var oldScope = _options.UseNewServiceResolutionScope ? context.RequestServices : null;
+        using var scope = _options.UseNewServiceResolutionScope ? context.RequestServices.GetRequiredService<IServiceScopeFactory>().CreateScope() : null;
+
         try
         {
+            if (scope != null)
+            {
+                context.RequestServices = scope.ServiceProvider;
+            }
+
             var exceptionHandlerFeature = new ExceptionHandlerFeature()
             {
                 Error = edi.SourceException,
@@ -216,6 +226,10 @@ private async Task HandleException(HttpContext context, ExceptionDispatchInfo ed
         finally
         {
             context.Request.Path = originalPath;
+            if (oldScope != null)
+            {
+                context.RequestServices = oldScope;
+            }
         }
 
         _metrics.RequestException(exceptionName, ExceptionResult.Unhandled, handler: null);

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerOptions.cs

@@ -17,6 +17,13 @@ public class ExceptionHandlerOptions
     /// </summary>
     public PathString ExceptionHandlingPath { get; set; }
 
+    /// <summary>
+    /// Gets or sets whether the handler needs to create a separate <see cref="IServiceProvider"/> scope and
+    /// replace it on <see cref="HttpContext"/>.
+    /// </summary>
+    /// <remarks>The default value is <see langword="false"/>.</remarks>
+    public bool UseNewServiceResolutionScope { get; set; }
+
     /// <summary>
     /// The <see cref="RequestDelegate" /> that will handle the exception. If this is not
     /// explicitly provided, the subsequent middleware pipeline will be used by default.

src/Middleware/Diagnostics/src/PublicAPI.Unshipped.txt

@@ -1,5 +1,8 @@
 #nullable enable
+Microsoft.AspNetCore.Builder.ExceptionHandlerOptions.UseNewServiceResolutionScope.get -> bool
+Microsoft.AspNetCore.Builder.ExceptionHandlerOptions.UseNewServiceResolutionScope.set -> void
 Microsoft.AspNetCore.Diagnostics.IExceptionHandler
 Microsoft.AspNetCore.Diagnostics.IExceptionHandler.TryHandleAsync(Microsoft.AspNetCore.Http.HttpContext! httpContext, System.Exception! exception, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.ValueTask<bool>
 Microsoft.AspNetCore.Diagnostics.StatusCodeReExecuteFeature.OriginalStatusCode.get -> int
+static Microsoft.AspNetCore.Builder.ExceptionHandlerExtensions.UseExceptionHandler(this Microsoft.AspNetCore.Builder.IApplicationBuilder! app, string! errorHandlingPath, bool newScope) -> Microsoft.AspNetCore.Builder.IApplicationBuilder!
 static Microsoft.Extensions.DependencyInjection.ExceptionHandlerServiceCollectionExtensions.AddExceptionHandler<T>(this Microsoft.Extensions.DependencyInjection.IServiceCollection! services) -> Microsoft.Extensions.DependencyInjection.IServiceCollection!