improvement: Better message for request validation exceptions

.gitlab-ci.yml

@@ -1,10 +1,10 @@
 include:
   - project: 'fusonic/devops/images/gitlab-ci-tools'
     file: 'dotnet_test.yml'
-    ref: '5.3'
+    ref: '5.9'
   - project: "fusonic/devops/images/gitlab-ci-tools"
     file: "release_tool.yml"
-    ref: "5.3"
+    ref: "5.9"
 
 stages:
   - build

src/AspNetCore/src/Validation/RequestValidationDecorator.cs

@@ -25,6 +25,6 @@ public Task<TResult> Handle(TCommand request, CancellationToken cancellationToke
                                     kv => kv.Key,
                                     kv => kv.Value!.Errors.Select(e => e.ErrorMessage).ToList());
 
-        throw new RequestValidationException(errors);
+        throw new RequestValidationException(typeof(TCommand), errors);
     }
 }

src/AspNetCore/src/Validation/RequestValidationException.cs

@@ -3,7 +3,35 @@
 
 namespace Fusonic.Extensions.AspNetCore.Validation;
 
-public class RequestValidationException(IDictionary<string, List<string>> errors) : Exception("One or more validation errors occurred.")
+public class RequestValidationException : Exception
 {
-    public IDictionary<string, List<string>> Errors { get; } = errors;
+    public RequestValidationException(IDictionary<string, List<string>> errors) 
+        : base($"""
+                One or more validation errors occurred.
+                {GetErrorMessage(errors)}
+                """)
+    {
+        Errors = errors;
+    }
+
+    public RequestValidationException(Type requestType, IDictionary<string, List<string>> errors) 
+        : base($"""
+                One or more validation errors occurred.
+                Request type: {requestType.FullName}.
+                {GetErrorMessage(errors)}
+                """)
+    {
+        RequestType = requestType;
+        Errors = errors;
+    }
+
+    public IDictionary<string, List<string>> Errors { get; }
+    public Type? RequestType { get; }
+
+    private static string GetErrorMessage(IDictionary<string, List<string>> errors)
+    {
+        var messages = errors.SelectMany(err => err.Value.Select(e => $"{err.Key}: {e}"));
+        var message = string.Join(Environment.NewLine, messages);
+        return message;
+    }
 }

src/Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>9.1.0</Version>
+    <Version>9.1.1</Version>
     <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>