How to test a parallel port C# application?

Question

I am implementing a simple C# application that controls some leds (on/off) through the parallel port. My problem now is that I would like to test the application and monitor the behavior of the signals that I send out.

Question:

Is it possible to have like a virtual parallel port address on my windows PC and monitor this port ? Note that I don't have a LPT port in my laptop, this application will be executed on another PC.

Answer 1

Encapsulate your basic parallel port operations in a class that implements an interface. Then use constructor injection to provide an implementation of your parallel port interface to any class that needs to use a parallel port. That way, you can mock out a fake parallel port implementation to provide whatever sort of data you want to use for the purposes of your unit tests.