One of the critical aspects of testing to understand is how to use test doubles. Mock objects is a subject that can be difficult to grasp and often developers find themselves feeling like they are mocking too much and testing too little. In this session we will cover test doubles with a focus on mock objects, explaining how they are used as well as why they are used. After this session you will have a renewed confidence in writing tests and be well on your way to writing effective unit tests or specs for your code.