npm to run shell commands is all well and good, but as you can imagine it has its limits. When you want to really complicate things, you'll need to start writing tasks in Node.js. To do this we'll need that index.js file we specified in our package.json entry point field.
Create a file called index.js. Next we'll need to download a package which compiles watches our Sass files. The package is
node-sass is a Node "wrapper" of the
LibSass port of Sass. This means we write code familiar to Node which then uses
LibSass to actually compile and do whatever else we ask.
So first we'll run the command to download and install
node-sass into our project:
npm install node-sass --save-dev