How do I get the real error message in HttpClient response.ReasonPhrase?

.net, asp.net, asp.net-web-api, c#

Solution

The new CreateResponse() method:

    /// <summary>
    /// Recognizes common repository exceptions and creates a corresponding error response.
    /// </summary>
    /// <param name="request">The request to which the response should be created.</param>
    /// <param name="ex">The exception to handle.</param>
    /// <returns>An error response containing the status code and exception data, or null if this is not a common exception.</returns>
    private HttpResponseMessage CreateResponse(HttpRequestMessage request, Exception ex)
    {
        string message = ex.Message;

        HttpStatusCode code = 0;

        if      (ex is KeyNotFoundException)        code = HttpStatusCode.NotFound;
        else if (ex is ArgumentException)           code = HttpStatusCode.BadRequest;
        else if (ex is InvalidOperationException)   code = HttpStatusCode.BadRequest;
        else if (ex is UnauthorizedAccessException) code = HttpStatusCode.Unauthorized;
        else if (ex is HttpException)
        {
            // HttpExceptions are thrown when request between IdentityServer and the API server have failed.
            // IdentityServer has generated an error, the API server received it and now it needs to relay it back to the client.
            var httpException = (HttpException) ex;

            code = (HttpStatusCode) httpException.GetHttpCode();
            message = httpException.Message;
        }
        else
        {
            code = HttpStatusCode.InternalServerError;

            // For security reasons, when an exception is not handled the system should return a general error, not exposing the real error information
            // In development time, the programmer will need the details of the error, so this general message is disabled.
#if DEBUG
            message = ex.Message;
#else
            message = Errors.InternalServerError;
#endif
        }

        // For some reason the request.CreateErrorResponse() method ignores the message given to it and parses its own message.
        // The error response is constructed manually.
        return CreateErrorResponse(request, code, message);
    }

    private HttpResponseMessage CreateErrorResponse(HttpRequestMessage request, HttpStatusCode code, string message)
    {
        var content = new { Message = message };

        return new HttpResponseMessage(code)
        {
            ReasonPhrase = message,
            RequestMessage = request,
            Content = new ObjectContent(content.GetType(), content, new JsonMediaTypeFormatter())
        };
    }
}

Hope this just saved someone's day... ;)

Problem

My Setting I have 2 WebApi projects with the following flow: - User makes request to API 1 - API 1 makes request to API 2 on behalf of the user (using an `HttpClient`). ``` using (var client = new HttpClient()) { client.SetBearerToken(token); string endpoint = PbbSettings.Identity.Users.Delete.Replace("{userId}", userId); // Attempt deletion of the user using (var response = await client.DeleteAsync(endpoint)) { // Throw exception if not succeeded EnsureSuccess(response); } } ``` The Problem So the flow of control and information works fine. The problem is that when API 2 responds with an error, `response.ReasonPhrase` says "Bad Request" or "Internal Server Error", instead of the message I set in the exception. Been spitting blood on this for a whole day now. Any insights? More Info (TLDR) For clarity, all my APIs have a global exception filter registered to handle errors: ``` public class RepositoryExceptionsHandlerAttribute : ExceptionFilterAttribute { public override void OnException(HttpActionExecutedContext context) { HandleException(context); base.OnException(context); } public override Task OnExceptionAsync(HttpActionExecutedContext context, CancellationToken cancellationToken) { HandleException(context); return base.OnExceptionAsync(context, cancellationToken); } /// <summary> /// Recognizes common repository exceptions and if necessary creates a response and updates the context. /// </summary> /// <param name="context">The context in which the exception was thrown.</param> private void HandleException(HttpActionExecutedContext context) { var response = CreateResponse(context.Request, context.Exception); if (response != null) context.Response = response; } /// <summary> /// Recognizes common repository exceptions and creates a corresponding error response. /// </summary> /// <param name="request">The request to which the response should be created.</param> /// <param name="ex">The exception to handle.</param> /// <returns>An error response containing the status code and exception data, or null if this is not a common exception.</returns> private HttpResponseMessage CreateResponse(HttpRequestMessage request, Exception ex) { string message = ex.Message; if (ex is KeyNotFoundException) return request.CreateErrorResponse(HttpStatusCode.NotFound, message); if (ex is ArgumentException) return request.CreateErrorResponse(HttpStatusCode.BadRequest, message); if (ex is InvalidOperationException) return request.CreateErrorResponse(HttpStatusCode.BadRequest, message); if (ex is UnauthorizedAccessException) return request.CreateErrorResponse(HttpStatusCode.Unauthorized, message); #if !DEBUG // For security reasons, when an exception is not handled the system should return a general error, not exposing the real error information // In development time, the programmer will need the details of the error, so this general message is disabled. request.CreateErrorResponse(HttpStatusCode.InternalServerError, Errors.InternalServerError); #endif return null; } } ``` This works fine between the user and API 1. But when API 1 and API 2 do their thing, the response creation ignores the message I put in and sets the status as the reason.

Original source