Brian Mains on Focusing on Testability – An Example

Brian Mains wrote a nice post on how to modify the code for better testability. Now, it’s not  that the code is not nicer, but testability hasn’t changed – it was testable before and it remained so after.

I’d like to repeat Roy’s comments on the blog:

we focused a lot of effort in making sure that you need to write very little code to make things testable where possible.

in this case the same result can be achieved with:


Isolate.WhenCalled(() => HttpContext.Current.Handler).WillReturn(page);

var fakeTraceContext = ((Page)HttpContext.Current.Handler).Trace;

//act goes here

Isolate.Verify.WasCalledWithAnyArguments(() => { fakeTraceContext.Warn(null, null, null); });

//this works because all fakes are recursive with Typemock – so the trace, handler props are already fake. just use them as you with to verify calls.

Recursive fakes are very powerful:

  • They allow you to write less test code and still achieve the same goal.
  • You don’t need to set behavior on what you don’t need
  • Tests are more robust, because there’s less to break

And at the end of the day, remember that testability is not the issue. It’s your code – and because you’re going to live with it for a long time, make sure you design it they way you want.