Node Package - Is it possible to interpolate a variable in package.json?

Question

I have a static site that compile Sass using node-sass.

Currently I'm using Grunt to watch the file, but I feel it's overkill because I can use their built-in CLI.

So I add this in my package.json:

// package.json
...
"scripts": {
  "sass": "node-sass -w input/dir -o output-dir/" 
}

The problem is, I need to require a Sass framework module (installed globally) in the --include-path. I can do this in Gruntfile:

// Gruntfile.js
sass: {
  options: {
    includePaths: require("the-framework").includePaths()
  },
  ...
},

So the first thing that come to my mind is to interpolate the string like:

// package.json
...
"scripts": {
  "sass": "node-sass -w input/dir -o output-dir/ --include-path " + require("the-framework").includePaths()
}

And as expected, it doesn't work. Well the script runs, but the interpolated variable is ignored.

Any solution or alternative? If possible, I would prefer not to create additional file just to store the variable.

Thanks

Answer 1

I dont know is it a right way to do it, but I can explain how I will would solve this task.

You cant interpolate variables in package.json, cause it must be valid json. That you can is to write bash commands here.

1) You can write node command that will needed result. You should take care if includePaths() does not return string.

Node options:
  -e, --eval script     evaluate script
  -p, --print           evaluate script and print result

So it would be something like

node -e "console.log(require('the-framework').includePaths())"

Or shorter version with --print

node -p "require('the-framework').includePaths()"

2) Inline output of previous command into sass script. Take care of right escaping.

{
  "scripts": {
      "sass": "node-sass -w input/dir -o output-dir/ --include-path $(node -p \"require('the-framework').includePaths()\")"
  }
}

More info about executing bash command you can find here.

P.S. Windows version differs

{
  "scripts": {
      "sass": "FOR /f \"delims=\" %v IN ('node -p \"require('edje').includePaths()[0]\"') DO node-sass -w assets/sass -o assets/css --include-path \"%v\""
  }
}

More info you can find here.