Mini CSS negator

css-negator.js

/**
  README.md
  1. Copy & paste the input file into third-party.css as raw CSS
  2. $ node css-negator.js
  3. When finished, the final copy will be in the file named: negated-output.css
*/

var css      = require('css');
var fs       = require('fs');
var colors   = require('colors');
var cleanCSS = require('clean-css');

/**
  `opts` is an array which can be empty, can contain either of the following two string values, or can contain both of the following two string values:

    "display-none"
    "visibility-hidden"

  setting these flags in the array signals the css negater to ignore `display:none` css key/value pairs or ignore `visibility:hidden` css key/value pairs.
*/
var opts = [/*"display-none", "visibility-hidden"*/];

console.log("*** Starting! ***".bold.cyan);

var inputFile = fs.readFileSync('third-party.css', 'utf8');

console.log(" * Finished reading the input file");

var ast = css.parse(inputFile);

ast.stylesheet.rules = ast.stylesheet.rules.map(function(rule) {
  if (rule.type === 'rule') {
    rule.declarations = rule.declarations.map(function(declaration) {
      if (opts.length && (
          (~opts.indexOf('display-none') && declaration.property == 'display' && declaration.value == 'none') ||
          (~opts.indexOf('visibility-hidden') && declaration.property == 'visibility' && declaration.value == 'hidden')
      )) {
        console.log(' Skipping declaration.');
      } else {
        declaration.value = 'inherit';
      }
      return declaration;
    });
  }
  return rule;
});

var css = css.stringify(ast);

/* Only keep the first special comment when minifying */
var minifiedCSS = new cleanCSS({ keepSpecialComments: 1}).minify(css).styles;

fs.writeFile("negated-output.css", minifiedCSS, function(err) {
  if (err) {
    console.log(err);
  } else {
    console.log("*** DONE! The file was saved as negated-output.css ***".bold.green);
  }
});

package.json

{
  "name": "mini-css-negator",
  "version": "1.0.0",
  "description": "Mini CSS negator",
  "main": "css-negator.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Alex DiLiberto <npm@alexdiliberto.com> (http://alexdiliberto.com/)",
  "license": "MIT",
  "dependencies": {
    "clean-css": "^3.4.5",
    "colors": "^1.1.2",
    "css": "^2.2.1"
  }
}