MapStatusCode not respected for MVC validation errors

[arjun-1]

I want to change the ProblemDetails.Type for a 422 response that is the result of MVC validation error (after having called AddProblemDetailsConventions).

Reading the documentation of MapStatusCode, this should be possible with:

services
  .AddProblemDetails(options =>
  {
    options.MapStatusCode = ctx => // change Type in case of 422
  }
  .AddProblemDetailsConventions()

I find however that the Type is not changed at all. In order to do so, I must replace the MvcProblemDetailsFactory (after calling AddProblemDetailsConventions) and substitute my own which has a modified CreateValidationProblemDetails:

services.Replace(
  ServiceDescriptor.Singleton<MvcProblemDetailsFactory, MyProblemDetailsFactory>()
);

Probably this is because Options.MapStatusCode is not being used in CreateValidationProblemDetails in ProblemDetailsFactory? Is there a way to change the produced Type using the functionality of this library?

[khellang]

Hi @arjun-1! 👋🏻

Sorry for the late reply. Maybe you could try to set the OnBeforeWriteDetails hook? It should let you modify the ProblemDetails object before it's written to the response:

Middleware/test/ProblemDetails.Tests/ProblemDetailsMiddlewareTests.cs

Lines 594 to 597 in a81989f

	options.OnBeforeWriteDetails = (_, details) =>
	{
	details.Extensions[nameof(ProblemDetailsOptions.OnBeforeWriteDetails)] = true;
	};