file.OpenReadStream() Cannot access closed stream error - mimekit

Question

I want Website users to submit a file through a Web form. Sometimes multiple files. Then these files should be emailed to a specific set of users. I have created an Email Service that accepts a List attachments.
`
public class EmailModel
{
public EmailAddressModel FromUser { get; private set; }
public List<EmailAddressModel> ToAddresses { get; private set; }
public List<EmailAddressModel> CcAddresses { get; private set; }
public List<EmailAddressModel> BccAddresses { get; private set; }
public List<IFormFile> Attachments { get; private set; }
public string Subject { get; private set; }
public string Body { get; private set; }
public bool isHTML { get; private set; }
public EmailModel(EmailAddressModel fromUser, List<EmailAddressModel> toAddresses, List<EmailAddressModel> ccAddresses, List<EmailAddressModel> bccAddresses, List<IFormFile> attachments, string subject, string body, bool isHTML)
{
FromUser = fromUser;
ToAddresses = toAddresses;
CcAddresses = ccAddresses;
BccAddresses = bccAddresses;
Attachments = attachments;
Subject = subject;
Body = body;
this.isHTML = isHTML;
}
}
EmailService Prepare Email Attachments.
private void PrepareEmailAttachments()
{
foreach (IFormFile attachment in Email.Attachments)
{
if (attachment.Length > 0)
{
var stream = attachment.OpenReadStream();
using (MemoryStream mStream = new MemoryStream())
{
stream.CopyTo(mStream);
var data = mStream.ToArray();
Builder.Attachments.Add(attachment.FileName, data);
}
}
}
}
Test Code Snippet
List<IFormFile> Attachments = new List<IFormFile>();
using (var stream = File.OpenRead("TestFile\\Test Document.pdf"))
{
var file = new FormFile(stream, 0, stream.Length, null, Path.GetFileName(stream.Name))
{
Headers = new HeaderDictionary(),
ContentType = "application/pdf"
};
Attachments.Add(file);
}
EmailModel Email = new EmailModel(
From,
To,
CC,
BCC,
Attachments,
"Test Email",
"This is a build test",
true);
`
var stream = attachment.OpenReadStream() I am getting a "Cannot Access a closed stream."
`
Message: 
Test method BA.Common.Tests.SendMail.SendEmail threw exception:
System.ObjectDisposedException: Cannot access a closed Stream.
Stack Trace: 
BufferedFileStreamStrategy.Seek(Int64 offset, SeekOrigin origin)
FileStream.set_Position(Int64 value)
ReferenceReadStream.ctor(Stream inner, Int64 offset, Int64 length)
FormFile.OpenReadStream()
EmailService.PrepareEmailAttachments() line 111
EmailService.SendMail() line 43
SendMail.SendEmail() line 58
`
I am expecting that the attachment gets loaded into the MimeKit to be emailed. I have confirmed that the file is ready in attachment. But I cannot figure out why I can't open the attachment.

Answer 1

One of my good friends answered me via email after seeing my post, but he didn't answer here so I will. It turns out that the error was in my integration test, not my project.
I thought that once I added the file to the (Attachment.Add(file); that I could dispose of the stream. In my test I was closing my stream before loading my EmailModel. Simple fix, but I should have kept working up my stack trace to find the error. Thanks Andrew!