No content is written in PDFs uploaded using the instructions for multipart/form-data

I have an objective to send a PDF file from one server to a REST API which handles some archiving. I am using .NET Core 3.1 and RestEase

I have a simple console app that runs at a certain time everyday. The relevant code is as follows:

using System;
using System.Linq;
using System.Threading.Tasks;
using RestEase;

namespace CandidateUploadFile
{
    class Program
    {
        static async Task Main(string[] args)
        {
            try
            {
                var apiClientBuilder = new ApiClientBuilder<ITestApi>();
                var api = apiClientBuilder.GetApi("https://localhost:5001");
                var candidate = await api.GetCandidateByEmailAddress("[e-mail]");
                var fileName = "tester.pdf";
                var fileBytesToUpload = await FileHelper.GetBytesFromFile($@"./{fileName}");
                var result = await api.UploadCandidateFileAsync(fileBytesToUpload, candidate.Data.First().Id, fileName);
            }
            catch (Exception e)
            {
                System.Console.WriteLine(e);
            }
        }
    }
}

apiClientBuilder does some auth-header adding, and that’s really it. I’m certain that bit isn’t relevant.

ITestApi looks like this:

using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;
using Models;
using RestEase;

namespace CandidateUploadFile
{
    public interface ITestApi : IApi
    {
        [Get("v1/candidates/{candidateId}")]
        Task<Models.Response<Candidate>> GetCandidate([Path] string candidateId);

        [Get("v1/candidates")]
        Task<Models.Response<IEnumerable<Candidate>>> GetCandidateByEmailAddress([Query] string email);

        [Get("v1/candidates")]
        Task<Models.Response<IEnumerable<Candidate>>> GetCandidates();

        [Post("v1/candidates/{candidateId}/files?perform_as=327d4d21-5cb0-4bc7-95f5-ae43aabc2db7")]
        Task<string> UploadFileAsync([Path] string candidateId, [Body] HttpContent content);

        [Get("v1/users")]
        Task<Models.Response<IEnumerable<User>>> GetUsers();
    }
}

Per the docs, I’m using an extension method to handle the multipart/form-data piece, along with headers that are required by my API. That extension method looks like this:

using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace CandidateUploadFile
{
    public static class ApiExtension
    {
        public static async Task<string> UploadCandidateFileAsync(this ITestApi api, byte[] data, string candidateId, string fileName)
        {
            var content = new MultipartFormDataContent();

            var fileContent = new ByteArrayContent(data);
            fileContent.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
            fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
            {
                Name = "file",
                FileName = fileName
            };

            content.Add(fileContent);

            return await api.UploadFileAsync(candidateId, content);
        }
    }
}

So what will happen when my console app executes is: I will get a successful response from the upload endpoint, and the file on the archive server gets created, but it’s blank.

It may be important to know that this does not happen when I send, say, a .txt file. The .txt file will save with the expected content.

Not sure where to start on this one; it’s not clear as to if this is a library issue or something else. Any insight would be helpful. Thank you!

[canton7]

(also, reading a file async does nothing unless it was opened as async. You’d also be better off grabbing a FileStream and using that as a SteamContent: then the whole thing doesn’t have to be loaded into memory at once).

Glad you solved it!

[sdg-sjb]

I see… That explains why .txt files were working and not pdfs… Yikes, my bad. Foolish of me. Thank you for the help @StefH @canton7