cssMinifier.js

const fs = require('fs');

fs.readFile('./page-setup.css', { encoding: 'utf-8' }, (err, data) => {
  console.log(cssMinifier(data));
});

function cssMinifier(cssString) {
  const removeSpaceAroundChar = char => replace(new RegExp(`\\s*${char}\\s*`, 'g'), char);
  const removeNewLine = replace(/[\r\n]/g, '');
  const shrinkers = map(removeSpaceAroundChar)([',', ';', ':', '{', '}']);

  return pipe(trim, removeNewLine, ...shrinkers)(cssString);
}