Question

Here is the code:

public interface IAccessPoint
{
    int BackHaulMaximum { get; set; }

    bool BackHaulMaximumReached();
    void EmailNetworkProvider();
}

public class AccessPoint : IAccessPoint
{

    public int BackHaulMaximum { get; set; }

    public bool BackHaulMaximumReached()
    {
        if (BackHaulMaximum > 80)
        {
            EmailNetworkProvider();
            return true;
        }
        return false;
        }

    public void EmailNetworkProvider()
    {

    }
}

//Test
[Test]
public void NetworkProviderShouldBeEmailedWhenBackHaulMaximumIsReached()
{
        var apMock = MockRepository.GenerateMock<IAccessPoint>();

        apMock.Stub(x => x.BackHaulMaximum).Return(81);

        Assert.AreEqual(true, apMock.BackHaulMaximumReached());

        apMock.AssertWasCalled(x => x.EmailNetworkProvider());
 }

Answer 1

You shouldn’t be mocking the class that you are testing. You should only be mocking the classes that class under test depends on. Something like this:

public interface IAccessPoint
{
    int BackHaulMaximum { get; set; }

    bool BackHaulMaximumReached();
    void EmailNetworkProvider();
}

public class AccessPoint : IAccessPoint
{
    private IMailProvider Mailer { get; set; }

    public AccessPoint( IMailProvider provider )
    {
        this.Mailer = provider ?? new DefaultMailProvider();
    }

    public int BackHaulMaximum { get; set; }

    public bool BackHaulMaximumReached()
    {
        if (BackHaulMaximum > 80)
        {
            EmailNetworkProvider();
            return true;
        }
        return false;
        }

    public void EmailNetworkProvider()
    {
        this.Mailer.SendMail(...);
    }
}

[Test]
public void NetworkProviderShouldBeEmailedWhenBackHaulMaximumIsReached()  
{  
    var mailerMock = MockRepository.GenerateMock<IMailProvider>();  

    mailerMock .Expect( m => m.SendMail( ... specify argument matches ... ) ); 

    var accessPoint = new AccessPoint( mailerMock ); 

    accessPoint.BackHaulMaximum = 81;

    Assert.IsTrue( accessPoint.BackHaulMaximumReached() );

    mailerMock.VerifyAllExpectations();
}