Context/Spec style testing and my approach to BDD


I borrow heavily my approach to testing from a combination of Ayende’s Rhino Tools tests, and my reading of the Rspec beta book. But I think I’ve stumbled onto something I’m happy with and I can generate reports out of. Let’s go over some basic rules first:

  1. Move as much common setup logic to a base class as possible.
  2. Use your class name as the context
  3. methods are rules beginning with “should”
  4. create a new subclass of the base context every time you have a new scenario

Code ends up looking like so:

 

public class BaseAddVacationContext
{
protected AddVacationRequest _submission;
protected IEmailSender _sender;
protected IUserInformation _information;
protected ICrudRepo&ltLeaveRequest> _leaverepo;
protected LeaveRequest _request;
[SetUp]
public virtual void SetUp()
{
_sender = MockRepository.GenerateMock&ltIEmailSender>();
_information = MockRepository.GenerateMock&ltIUserInformation>();
_leaverepo = MockRepository.GenerateMock&ltICrudRepo&ltLeaveRequest>>();
_submission = new AddVacationRequest(_sender, _information, _leaverepo);
_request = new LeaveRequest() { UserName = "userman" };


}
}
[TestFixture]
public class SpecAddVacationRequestWhenEmployeeSubmitsRequest : BaseAddVacationContext
{


[SetUp]
public override void SetUp()
{
base.SetUp();
_information.Stub(x => x.GetManagersEmailAddresses("userman")).Return(new[] { "[email protected]", "[email protected]" });
_information.Stub(x => x.GetReviewersEmailAddress("userman")).Return(new[] { "[email protected]", "[email protected]" });
_information.Stub(x => x.GetUserEmail("userman")).Return("[email protected]");
_submission.Execute(_request);

}
[Test]
public void should_email_all_managers()
{
_sender.AssertWasCalled(x => x.Send(Arg&ltMessage>.Matches(y => y.To == "[email protected]")));
_sender.AssertWasCalled(x => x.Send(Arg&ltMessage>.Matches(y => y.To == "[email protected]")));
}

[Test]
public void should_send_email_to_user()
{
_sender.AssertWasCalled(x => x.Send(Arg&ltMessage>.Matches(y => y.To == "[email protected]")));
}

[Test]
public void should_store_leave_request_in_database()
{
_leaverepo.AssertWasCalled(x=>x.Create(Arg<LeaveRequest>.Matches(u=>u == _request)));
}

[Test]
public void should_email_all_reviewers()
{
_sender.AssertWasCalled(x => x.Send(Arg<Message>.Matches(y => y.To == "[email protected]")));
_sender.AssertWasCalled(x => x.Send(Arg<Message>.Matches(y => y.To == "[email protected]")));
}
}
[TestFixture]
public class SpecAddVacationRequestWhenRequesWasAlreadyMadeForThoseDays : BaseAddVacationContext
{


[SetUp]
public override void SetUp()
{
base.SetUp();

_leaverepo.Stub(x=>x.Create(null)).Throw(new EmployeeAlreadyRequestedTheseDaysOff()).IgnoreArguments();
}
[Test]
public void should_not_send_email_to_anyone(){

_sender.AssertWasNotCalled(x => x.Send(Arg<Message>.Is.Anything));
}
}

So here we have:

 

  • A setup that you need to override and call to setup context specific behavior
  • small small tests and asserts.
  • limited setup on mocks, you can use handrolled mocks or the real classes if you prefer (which I do often).
  • Use AssertWasCalled instead of .Expect() on my mocks

I’ll post more examples of this as they come up.

EDIT: typo in code and changes to show more than one context

Glad to be here