exposing methods for the purpose of testing is bad design, whether or not you are only doing it in a test environment. if you have a method that is sufficiently complex and warrants its own testing, put it in it's own module file and test that module file on it's own - no need to break your design and modify your runtime module exports based on runtime environment checks
http://lostechies.com/derickbailey/2014/01/03/semantics-modu...