(C#) exceptions do not copy the response body into exceptions

If I have a C# WebApi controller return a BadRequestErrorMessageResult (as an example, it’s valid to return a body with other status codes)

       [SwaggerResponse(HttpStatusCode.OK, "PutWidgetResponse", typeof(ApiResponse<WidgetModel>))]
        public async Task<IHttpActionResult> PutWidget(int id, [FromBody] WidgetModel widget)
        {
            // Validate
            if (id <= 0)
            {
                return BadRequest("id={0} is invalid", id);
            }
            // etc

The response body has the following JSON (from memory, it’s approximately this):

{ "message" : "id=0 is invalid"}

The generated C# proxy (I’ve removed a few irrelevant lines from this snippet) sets the response body to null:

            _httpResponse = await this.Client.HttpClient.SendAsync(_httpRequest, cancellationToken).ConfigureAwait(false);
            HttpStatusCode _statusCode = _httpResponse.StatusCode;
            string _responseContent = null;
            if ((int)_statusCode != 200)
            {
                var ex = new HttpOperationException(string.Format("Operation returned an invalid status code '{0}'", _statusCode));
                ex.Request = new HttpRequestMessageWrapper(_httpRequest, _requestContent);
                ex.Response = new HttpResponseMessageWrapper(_httpResponse, _responseContent);

In my use case it’d be great to have the Response body get copied into the exception so we can mine it for more useful information.

Is it possible to get this changed so the response body is copied into the exception?

[koolraap]

TL;DR garbage in==garbage out.

Thanks, that clears it up. It was user error on my part and non-obvious Swashbuckle behaviour.

Initially I’d avoided decorating my controller methods with this… [SwaggerResponse(HttpStatusCode.Unauthorized, "", typeof(Exception))] …as it was generating object in Autorest. Turns out Swashbuckle doesn’t have XML documentation available for System.Exception so it doesn’t emit anything useful.

Changing to this… [SwaggerResponse(HttpStatusCode.Unauthorized, "", typeof(MyExceptionModel))] Autorest works as expected.

[brentonw]

@stankovski - so what happens when you can’t control the Swagger?

Why not just set the body and allow the caller of the generated code to access anything they need?