Modify API response before passing back to controller in .NET Core

Question

I'm able to achieve same behavior easily in .NET Framework but coming to .NET Core I don't find needed methods to achieve same

Snippet: below response has only Getter no setter and CreateErrorResponse is not supported

var error = new HttpError
        {
           {
             "data", reqdInfo
           }
        };

context.Response = context.Request.CreateErrorResponse(HttpStatusCode.BadRequest, error);

I want to include above error info in the response before i give back control to controller

Edit: In framework

Answer 1

ASP.NET was heavily reworked since the pre-.NET Core version. Something potentially similar can be achieved with Results class (available since ASP.NET Core 6). For example:

app.Use(async (context, next) =>
{
    if (context.Request.Path.Value.Equals("/api/test/error", StringComparison.OrdinalIgnoreCase))
    {
        await Results.Problem(new ProblemDetails
            {
                Extensions = { { "data", new { Value = 1 } } }
            })
            .ExecuteAsync(context);
    }
    else
    {
        await next();
    }
});

Which produces the following result for /api/test/error:

{
    "type": "https://tools.ietf.org/html/rfc7231#section-6.6.1",
    "title": "An error occurred while processing your request.",
    "status": 500,
    "data": {
        "value": 1
    }
}

Potentially useful articles:

1. Handle errors in ASP.NET Core
2. Handle errors in ASP.NET Core web APIs
3. Write custom ASP.NET Core middleware