ASP. NET series: SmtpClient and asp. netsmtpclient for unit testing

ASP. NET series: SmtpClient and asp. netsmtpclient for unit testing

When SmtpClient is used to send an Email, we can create an ISmtpClient interface and a SmtpClientWrapper adaptation class. In the unit test, we can perform Mock or custom FackeSmtpClient for ISmtpClient, however, the Facke SMTP Server of nDumbster provides us with a more intuitive and simple way to perform unit tests. You can search for nDumbster through Nuget. Here netDumbster is used.

1. IEmailSender Interface

public interface IEmailSender{    void SendMail(string from, string to, string subject, string body);}

2. Implementation class of SMTPAdapter

public interfacepublic class SMTPAdapter : IEmailSender{    public void SendMail(string from, string to, string subject, string body)    {        var message = new MailMessage();        message.IsBodyHtml = true;        message.From = new MailAddress(from);        message.To.Add(new MailAddress(to));        message.Subject = subject;        message.Body = body;        using (var smtpClient = new SmtpClient())        {            if (smtpClient.Host == null)            {                smtpClient.Host = "localhost";            }            smtpClient.Send(message);        }    }}

3. Use nDumbster for unit testing

public class SMTPAdapterTest{    [Fact]    public void SendMailTest()    {        SimpleSmtpServer server = SimpleSmtpServer.Start(25);        IEmailSender sender = new SMTPAdapter();        sender.SendMail("sender@here.com", "receiver@there.com", "subject", "body");        Assert.Equal(1, server.ReceivedEmailCount);        SmtpMessage mail = (SmtpMessage)server.ReceivedEmail[0];        Assert.Equal("sender@here.com", mail.Headers["From"]);        Assert.Equal("receiver@there.com", mail.Headers["To"]);        Assert.Equal("subject", mail.Headers["Subject"]);        Assert.Equal("body", mail.MessageParts[0].BodyData);        server.Stop();    }}