Clean Vigour CSS from unwanted properties

parser.js

var fs = require('fs')
var LineByLine = require('line-by-line')

var bundle = 'bundle.css'
var _bundle = '_bundle.css'
var file = 'new.less'
var _file = '_new.less'

var cleanRegEx = /^((\s+)?((\.|\@|\d).+|color|background|border|a|html|body|div|section|div|body|section|img|thumb|\:\:).+|((\s+)?\}))/m
var emptyRegEx = /^((.+\,\n)+)?(.+\{)(\n+|\s+)\}\n?/gm
var resetRegEx = /\/\*\s(file.+reset)(\n|.)+(file.+variables.+)/gm

fs.exists(file, (exists) => {
  if (exists) fs.unlink(file)
  fs.writeFile(file, '')
})

fs.exists(_file, (exists) => {
  if (exists) fs.unlink(_file)
  fs.writeFile(_file, '')
})

fs.exists(_bundle, (exists) => {
  if (exists) fs.unlink(_bundle)
  fs.writeFile(_bundle, '')
})

fs.readFile(bundle, 'utf8', (err, data) => {
  if (err) throw err
  var result = data.replace(resetRegEx, '')
  fs.writeFile(_bundle, result)

  var bundleLines = new LineByLine(_bundle)
  bundleLines.on('line', (line) => {
    if (cleanRegEx.test(line)) {
      fs.appendFileSync(_file, `${line}\n`)
    }
  })

  bundleLines.on('end', () => {
    fs.readFile(_file, 'utf8', (err, data) => {
      if (err) throw err
      var result = data.replace(emptyRegEx, '').replace(emptyRegEx, '')
      fs.appendFileSync(file, `body.vijf {\n ${result} \n}`, 'utf8')
      
      fs.unlink(_file)
      fs.unlink(_bundle)
    })
  })
})