Unit testing with Jasmine

Let's first explore how we can use PhantomJS to run unit tests using Jasmine, JavaScript's testing framework (http://pivotal.github.io/jasmine/). There are several testing frameworks for JavaScript that are freely available to use. Some of the better known testing frameworks are Jasmine, QUnit, and Mocha. Why Jasmine? Jasmine is also one of the more popular testing frameworks.

Besides, Jasmine syntaxes are very much like the English language when used, making it easy to follow and read the content of the test, just like in a document. In this chapter, we will not discuss Jasmine in depth, but only concentrate on those parts that we will need in our code. For more information on how to use the Jasmine API, refer to the Jasmine project page at http://pivotal.github.io/jasmine/.

We will assume that you know about unit testing and are familiar with it. Let's start by creating a simple calculator in JavaScript that has the ability to perform addition,...