Let JsonException bubble through problem details in minimal APIs

[Youssef1313]

Fixes #64139

[Copilot]

Pull request overview

Updates minimal API JSON body binding to emit validation-style Problem Details when System.Text.Json throws a JsonException (e.g., missing required properties), aligning the behavior more closely with MVC/controller model binding.

Changes:

• Write HttpValidationProblemDetails via IProblemDetailsService when JSON body deserialization throws JsonException in RequestDelegateFactory.
• Add a functional test validating consistent Problem Details output for both a minimal endpoint and an MVC [ApiController] endpoint.
• Extend the SimpleWebSiteWithWebApplicationBuilder test app with endpoints/models to reproduce the required property scenario.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
src/Mvc/test/WebSites/SimpleWebSiteWithWebApplicationBuilder/Program.cs	Adds ProblemDetails services + new endpoints/model to exercise missing required property behavior.
src/Mvc/test/Mvc.FunctionalTests/SimpleWithWebApplicationBuilderTests.cs	Adds a functional test asserting Problem Details JSON for both minimal + MVC endpoints.
src/Http/Http.Extensions/src/RequestDelegateFactory.cs	Emits HttpValidationProblemDetails on JsonException during minimal API JSON body binding.

[mikekistler]

@Youssef1313 Thank you for this contribution!

I will let the engineering team weigh in on the details of this change but I fully support the effort to solve this problem.

[Youssef1313]

@BrennanConroy @halter73 @javiercn Can I get a review here please? Thanks.

[BrennanConroy]

While looking around, I noticed we don't set the Status on the problem details in the validation filter
https://source.dot.net/#Microsoft.AspNetCore.Routing/[ValidationEndpointFilterFactory.cs](https://source.dot.net/#Microsoft.AspNetCore.Routing/ValidationEndpointFilterFactory.cs,99),99
Should probably do that, either here or a separate change.

[Youssef1313]

Hmm, looks like this will eventually get applied anyways when it reaches to:

aspnetcore/src/Http/Http.Extensions/src/DefaultProblemDetailsWriter.cs

Line 56 in 05434a9

ProblemDetailsDefaults.Apply(context.ProblemDetails, httpContext.Response.StatusCode);

aspnetcore/src/Shared/ProblemDetails/ProblemDetailsDefaults.cs

Line 179 in 05434a9

problemDetails.Status = statusCode;

This is assuming that the DefaultProblemDetailsWriter is used and not any other custom writer that's written and registered by the user. For the case of a custom implementation, I'm not sure yet, I'll try to come up with a test to demonstrate how the behavior can be different. I assume we will need to also have some consistency there between what MVC does and what minimal API does.

Thanks for pointing that out @BrennanConroy!

[BrennanConroy]

We should keep RDF tests in the RDF area https://github.com/dotnet/aspnetcore/tree/main/src/Http/Http.Extensions/test

Should also check that RDG behavior matches probably would put the test in
https://github.com/dotnet/aspnetcore/blob/main/src/Http/Http.Extensions/test/RequestDelegateGenerator/RequestDelegateCreationTests.JsonBody.cs
so it tests both RDF and RDG