One of the two main topics of this book is Knockout.JS, a JavaScript library that simplifies the development process of rich and dynamic user interfaces. Knockout.JS is one of many libraries out there that implements a presentation design pattern, in particular the Model-View-ViewModel (MVVM).

We will review Version 3.1 and its most important concepts and features using several examples, and try to understand why this library is so important in relation to testing a web application.

However, this book is not intended to be a complete Knockout.JS compendium; please refer to the Knockout.JS website documentation (http://knockoutjs.com/documentation/introduction.html) to discover all the advanced topics and references that are not covered in this chapter.

In this chapter, you will learn: