CHAPTER 5
Unit Testing
Unit Testing Backbone Applications With Jasmine Introduction One definition of unit testing is the process of taking the smallest piece of testable code in an application, isolating it from the remainder of your codebase and determining if it behaves exactly as expected. In this section, we’ll be taking a look at how to unit test Backbone applications using a popular JavaScript testing framework called Jasmine from Pivotal Labs. For an application to be considered “well”-tested, distinct functionality should ideally have its own separate unit tests where it’s tested against the different conditions you expect it to work under. All tests must pass before functionality is considered “complete”. This allows developers to both modify a unit of code and it’s dependencies with a level of confidence about whether these changes have caused any breakage. As a basic example of unit testing is where a developer may wish to assert whether passing specific values through to a sum function results in the correct output being returned. For an example more relevant to this book, we may wish to assert whether a user adding a new Todo item to a list correctly adds a Model of a specific type to a Todos Collection. When building modern web-applications, it’s typically considered best-practice to include automated unit testing as a part of your development process. Whilst we’ll be focusing on Jasmine as a solution for this, there are a number of other alternatives worth considering, including QUnit.
Jasmine Jasmine describes itself as a behavior-driven development (BDD) framework for testing JavaScript code. Before we jump into how the framework works, it’s useful to understand exactly what BDD is. 99