Improve Error Handling for RFC 7807 Compatibility — Add ProcessResponseAsync

[saampaark]

Currently, when consuming APIs that follow RFC 7807 (Problem Details for HTTP APIs), the autogenerated client does not expose response.Content in ApiException, making it difficult to access the actual error body content when an error (e.g., 400 Bad Request) is returned.

Structured error details should be returned in the body using application/problem+json, which requires access to response.Content. However, since the client does not expose this directly, we are forced to intercept it by implementing a partial method like this:

public partial class MyClient 
{
    partial void ProcessResponse(
        HttpClient client,
        HttpResponseMessage response)
    {
        if (!response.IsSuccessStatusCode)
        {
            // Extract problem details into ReasonPhrase (as workaround)
            response.ReasonPhrase = response.Content.ReadAsStringAsync().Result;
        }
    }
}

Consider adding support for:

• ProcessResponseAsync (in addition to the sync ProcessResponse) in order to avoid calling .Result which blocks the thread and is an antipattern.
• Easier access to the response content.

[HavenDV]

I also actively use Problem Details - can you try the latest preview version of the package instead of the stable one, I think this problem is already solved

[saampaark]

I'm currently using 0.28.1-dev.75.

catch (global::System.Exception __ex)
{
    throw new global::Zomp.Run2Run.Api.Remote.ApiException(
        message: __response.ReasonPhrase ?? string.Empty,
        innerException: __ex,
        statusCode: __response.StatusCode)
    {
        ResponseHeaders = global::System.Linq.Enumerable.ToDictionary(
            __response.Headers,
            h => h.Key,
            h => h.Value),
    };
}

Upon exception, it never accesses .Content

[HavenDV]

What is you OpenAPI operation definition for this endpoint?

We explicitly specify this for all endpoints:

    public static void MapEndpoints(this WebApplication app)
    {
        var group = app.MapGroup("/")
            // All endpoints require authorization by default
            // You can override at the group or endpoint level if needed
            .RequireAuthorization()

            .ProducesValidationProblem()
            .ProducesProblem(StatusCodes.Status401Unauthorized)
            .ProducesProblem(StatusCodes.Status403Forbidden)
            .ProducesProblem(StatusCodes.Status404NotFound)
            .ProducesProblem(StatusCodes.Status500InternalServerError);

[HavenDV]

Also generator can understand "default" and "4xx" like responses from OpenAPI schema and generate suitable code for this. But in this case you possible need to tweak generation and add some transformers.

https://swagger.io/docs/specification/v3_0/describing-responses/

[saampaark]

Thank you, I'll try it soon.