gistfile1.cs

    [Subject("Registering a user")]
    public class when_username_already_exists : Membership_service_subscription_context
    {
        static Exception exception;

        Because of = () => {
            signup.Username = "username";
            exception = Catch.Exception(() => suo.Register(signup));
        };

        It must_throw_a_validation_exception = () => {
            exception.ShouldNotBeNull();
            exception.ShouldBeOfType<ValidationException>();
        };
    }