RFC9110 - UnprocessableContent

[Kristian Hellang]

Background and Motivation

Now that RFC 9110 - HTTP Semantics is official, with the inclusion of the 422 Unprocessable Content status code, I'd like to propose the following changes to ASP.NET Core APIs.

Existing (shipped) members containing UnprocessableEntity is kept, but will simply forward to its UnprocessableContent counterpart.

Proposed API

namespace Microsoft.AspNetCore.Http;

public static class StatusCodes
{
+    public const int Status422UnprocessableContent = 422;
}

public static partial class Results
{
+    public static IResult UnprocessableContent(object? error = null) { throw null; }
}

public static class TypedResults {
-    public static UnprocessableEntity UnprocessableEntity();
+    public static UnprocessableContent UnprocessableContent();
-    public static UnprocessableEntity<TValue> UnprocessableEntity<TValue>(TValue? error) { throw null; }
+    public static UnprocessableContent<TValue> UnprocessableContent<TValue>(TValue? error) { throw null; }
}

namespace Microsoft.AspNetCore.Http.HttpResults;

-public sealed class UnprocessableEntity : IResult, IEndpointMetadataProvider { }
+public sealed class UnprocessableContent : IResult, IEndpointMetadataProvider { }

-public sealed class UnprocessableEntity<TValue> : IResult, IEndpointMetadataProvider { }
+public sealed class UnprocessableContent<TValue> : IResult, IEndpointMetadataProvider { }

Alternative Designs

Keeping the old name as-is? Should the existing UnprocessableEntity APIs be marked as [Obsolete]?

Risks

I'm not sure there are any.

[Kristian Hellang]

BTW, this is what the changes would look like (inside Microsoft.AspNetCore.Http only): main...khellang:unprocessable-content

[David Fowler]

This diverges from MVC's ActionResult (https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.mvc.unprocessableentityresult?view=aspnetcore-6.0).

[Kristian Hellang]

Yeah, or MVC needs the same treatment?

[Kristian Hellang]

In this case, it's still not too late to rename some of the APIs. In MVC's case, it'll all have to live side by side.

[Kristian Hellang]

@rafikiassumani-msft If this ships in .NET 7, it would be a breaking change to do anything with it in .NET 8. Is it too late to change this in .NET 7?