Test Utility class for creating POST MultipartFormData sending files (like a browser would) to the server

TestHttpContentUtils.cs

using System.Drawing;
using System.Net.Http;
using System.Net.Http.Headers;

namespace Infra.Assets.TestUtils
{
    public static class TestHttpContentUtils
    {
        const string FileFormFieldName = "file";

        public static HttpContent FileContent(
            string fileName,
            string contentType,
            Image image)
        {
            var content = new MultipartFormDataContent();
            var stream = TestImageUtils.StreamFrom(image);

            var disposition = new ContentDispositionHeaderValue("form-data");
            disposition.Name = FileFormFieldName;
            disposition.FileName = fileName;

            var file = new StreamContent(stream);
            file.Headers.ContentLength = stream.Length;
            file.Headers.ContentDisposition = disposition;
            file.Headers.ContentType = new MediaTypeHeaderValue(contentType);

            content.Add(file, FileFormFieldName);
            return content;
        }
    }
}