From 459cc1cb9ad156cc1fb9bb1bf12ea450e73b4370 Mon Sep 17 00:00:00 2001
From: TekH <h.tek@digitaldata.works>
Date: Wed, 3 Dec 2025 15:03:22 +0100
Subject: [PATCH] Add ValidationException handling to middleware

Enhanced the `ExceptionHandlingMiddleware` to handle
`ValidationException` from the `FluentValidation` library.
Set HTTP status code to 422 (Unprocessable Entity) for
validation errors and constructed error messages by
aggregating validation error details. Improved error
response clarity for validation-related issues.
---
 src/ReC.API/Middleware/ExceptionHandlingMiddleware.cs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/ReC.API/Middleware/ExceptionHandlingMiddleware.cs b/src/ReC.API/Middleware/ExceptionHandlingMiddleware.cs
index 0486ea6..c770712 100644
--- a/src/ReC.API/Middleware/ExceptionHandlingMiddleware.cs
+++ b/src/ReC.API/Middleware/ExceptionHandlingMiddleware.cs
@@ -1,4 +1,5 @@
 using DigitalData.Core.Exceptions;
+using FluentValidation;
 using ReC.Application.Common.Exceptions;
 using System.Net;
 using System.Text.Json;
@@ -65,6 +66,11 @@ public class ExceptionHandlingMiddleware
                 message = badRequestEx.Message;
                 break;
 
+            case ValidationException validationEx:
+                context.Response.StatusCode = (int)HttpStatusCode.UnprocessableEntity;
+                message = "Validation failed: " + string.Join("; ", validationEx.Errors.Select(e => e.ErrorMessage));
+                break;
+
             case NotFoundException notFoundEx:
                 context.Response.StatusCode = (int)HttpStatusCode.NotFound;
                 message = notFoundEx.Message;