Creating a test-driven module specification

We're going to create our module by loosely following the test-driven development (TDD) model (refer to http://en.wikipedia.org/wiki/Test-driven_development for more information). JavaScript is asynchronous, so the code can be executed in multiple time streams at once. This can sometimes make for a challenging mental puzzle.

A test suite is a particularly powerful tool when it comes to JavaScript development. It provides a quality assurance process and inspires confidence in a module's user base when tests are passing.

What's more, we can define our tests upfront as a way to map out the intended API before we even begin development.

In this recipe, we'll be doing just that by creating a test suite for a module that extracts the statistical information from MP3 files.

Getting ready

Let's create a new folder named mp3dat, with a file inside named index.js. Then, we will create two subfolders: lib and test, both containing index.js.

We'll also need some...