Re: How does one unit test a Mail Session?

Danno wrote:


As with most 3rd party libraries, you can put it behind an adapter.

interface MySession {
   void setProtocolForAddress(String addresstype, String protocol);
   // copy the remaining or better still, used methods from Session
   ...
}

public class SessionAdapter implements MySession {

  private Session theRealSession = Session.getInstance();

  public void setProtocolForAddress(String addresstype, String protocol){
    theRealSession.setProtocolForAddress(addressType, protocol);
  }

  // delegate remaining Session methods to 'theRealSession'
  ...
}

class MockSession implement MySession {

  public String lastAddressType;
  public String lastProtocol

  public void setProtocolForAddress(String addresstype, String protocol){
    lastAddressType = addressType;
    lastProtocol = protocol;
  }

}

class MyMail {

   void send(String message) {
     MySession session = createSession();
     if (imap) {
       session.setProtocolForAddress(addressType, "IMAP");
     } else {
       session.setProtocolForAddress(addressType, "SMTP");
     }
   }

   /** Protected so test can over ride*/
   protected MySession createSession() {
     return new SessionAdapter();
   }

}

class MyMailTest extends Testcase {

  public void testImapTransportProtocolUsed() {

    MockSession mockSession = new MockSession();

    MyMail mailer = new MyMail() {

       protected MySession createSession() {
           return mockSession;
       }

    };

    mailer.send("Boo");

    assertEquals("Wrong transport protocol", "IMAP",
mockSession.lastProtocol);
  }

}