WebApi + ClientApp, GraphQL, Reflection

Events-WebApi/Events.WebAPI/Util/Middleware/BadRequestOnRuleValidationException.cs

@@ -0,0 +1,68 @@
+using FluentValidation;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Filters;
+using Events.WebAPI.Util.Extensions;
+using Events.WebAPI.Contract.Command;
+
+namespace Events.WebAPI.Util.Middleware;
+
+public class BadRequestOnRuleValidationException : ExceptionFilterAttribute
+{
+  private readonly ILogger<BadRequestOnRuleValidationException> logger;
+
+  public BadRequestOnRuleValidationException(ILogger<BadRequestOnRuleValidationException> logger)
+  {
+    this.logger = logger;
+  }
+
+  public override void OnException(ExceptionContext context)
+  {
+    if (context.Exception is ValidationException)
+    {
+      
+      string exceptionMessage = context.Exception.CompleteExceptionMessage();        
+      logger.LogDebug("Validation error: {0}", exceptionMessage);
+      
+      ValidationException exc = (ValidationException)context.Exception;
+      Dictionary<string, List<string>> validationErrors = new Dictionary<string, List<string>>();
+      Dictionary<string, List<string>> validationErrorCodes = new Dictionary<string, List<string>>();
+
+      foreach(var failure in exc.Errors)
+      {
+        //remove prefix Dto. (part of Update and AddCommand)
+        string propertyName = failure.PropertyName.Replace(nameof(AddCommand<object, object>.Dto) + ".", "");
+        if (propertyName == nameof(AddCommand<object, object>.Dto))
+        {
+          propertyName = string.Empty;
+        }
+
+        validationErrors.GetOrCreate(propertyName).Add(failure.ErrorMessage);
+
+        if (!string.IsNullOrWhiteSpace(failure.ErrorCode))
+        {
+          validationErrorCodes.GetOrCreate(propertyName).Add(failure.ErrorCode);
+        }
+      }
+
+      var problemDetails = new ValidationProblemDetails(validationErrors.ToDictionary(d => d.Key, d => d.Value.ToArray()))
+      {
+        Detail = context.Exception.Message,
+        Title = "Validation exception",
+        Instance = context.HttpContext.TraceIdentifier
+      };
+      if (validationErrorCodes.Count > 0)
+      {
+        problemDetails.Extensions["errorCodes"] = validationErrorCodes.ToDictionary(d => d.Key, d => d.Value.ToArray());
+      }
+      context.Result = new ObjectResult(problemDetails)
+      {
+        ContentTypes = { "application/problem+json" },
+        StatusCode = StatusCodes.Status400BadRequest
+      };
+
+      context.HttpContext.Response.StatusCode = StatusCodes.Status400BadRequest;
+      context.ExceptionHandled = true;
+
+    }     
+  }   
+}