Writing module code

Now, it's time to in actual implementation details.

In this recipe, we will write some code for our hsl-to-hex module.

Getting ready

Let's ensure that we have a folder called hsl-to-hex, with a package.json file in it. The package.json file should contain hsl-to-rgb-for-reals as a dependency. If there isn't a node_modules folder, we need to ensure that we run npm install from the command line with the working directory set to the hsl-to-hex directory.

To get started, let's create a file called index.js in thehsl-to-hex folder, then open it in our favorite text editor.

How to do it...

The first thing we'll want to do in our index.js file is specify any dependencies we'll be using.

In our case, there's only one dependency:

var toRgb = require('hsl-to-rgb-for-reals') 

Typically, all dependencies should be declared at the top of the file.

Now, let's define an API for our module we're taking hue, saturation, and luminosity values and outputting a CSS compatible hex string.

Hue is in...