How do you unit test a mail sending function

Question

I have a function which creates a report and sends it to a user. What I've done is create a mock for the email function, and verify if the 'send' function of the email class was called.

So now I know that the function is called, but how do you unit test the body of the Send() function? How can I prove that the subject and body are correct and an attachment is attached to the email?

Answer 1

Can be done in following ways.

Step 1: Navigate to your Web.Config file and add the following tags to it.

<system.net>     <mailSettings>         <smtp deliveryMethod="SpecifiedPickupDirectory">             <specifiedPickupDirectory pickupDirectoryLocation="E:\MailTest\"/>         </smtp>     </mailSettings> </system.net> 

Make sure the directory you have specified for pickup location must exist.

Step 2 : Now test your email sending functionality. I have used button_click to test this functionality with the following code.

SmtpClient smtp = new SmtpClient(); MailMessage message = new MailMessage("[email protected]", "[email protected]","My Message Subject","This is a test message"); smtp.Send(message); 

Output : It will create .eml files inside the folder with a randonly generated GUID name, which is the email that we can see after receiving it. For me it created a file like c127d1d5-255d-4a5a-873c-409e23002eef.eml in E:\MailTest\ folder

Hope this helps :)

Answer 2

In your unit test tell your mocking framework to expect a call to Send() with a specific body text.

Example for Rhino Mocks:

var mockMail = MockRepository.GenerateMock<Mail>(); mockMail.Expect( m => m.Send("ExpectedFrom", "ExpectedTo", "ExpectedSubject", "ExpectedBodytext") );  mockMail.Send(...whatever...);  mockProvider.VerifyAllExpectations();