5.3. Mocking Objects

Some programs rely heavily on the use of objects, eschewing global variables and functions for loosely-coupled, well-encapsulated, and strongly polymorphic designs. This kind of code can be easier to maintain and understand—and to test. Well-factored code that adheres to intelligent interfaces between objects makes it possible to reuse and substitute equivalent implementations—including testing components.

This lab demonstrates how to create and use mock objects to test the inputs and outputs of code.