util.js

'use strict'
const fs = require('fs')
const path = require('path')

/*      outcome/
 * Create the folders in the path by creating each path in turn
 */
function ensureExists(path_, cb) {
  try {
    path_ = path.normalize(path_)
  } catch(err) {
    return cb(err)
  }
  let p = path_.split(path.sep)
  if(p[0] == '.') p.shift() // Don't create current directory
  else if(p[0] == '') { // Absolute path
    p.shift()
    p[0] = path.sep + p[0]
  }
  ensure_exists_1(p, 1)

  function ensure_exists_1(p, upto) {
    if(p.length < upto) cb(null, path_)
    else {
      let curr = path.join.apply(path, p.slice(0,upto))
      fs.mkdir(curr, '0777', (err) => {
        if (err && err.code != 'EEXIST' && err.code != 'EPERM') cb(err)
        else ensure_exists_1(p, upto+1)
      })
    }
  }
}

/*    understand/
 * given a name - try and make it as 'clean' as possible
 * so it's usable as a filename
 */
function sanitizeFilename(n) {
  let illegalRe = /[\/\?<>\\:\*\|"]/g;
  let controlRe = /[\x00-\x1f\x80-\x9f]/g;
  let reservedRe = /^\.+$/;
  let windowsReservedRe = /^(con|prn|aux|nul|com[0-9]|lpt[0-9])(\..*)?$/i;
  let windowsTrailingRe = /[\. ]+$/

  return n
    .replace(illegalRe, '')
    .replace(controlRe, '')
    .replace(reservedRe, '')
    .replace(windowsReservedRe, '')
    .replace(windowsTrailingRe, '')
}

module.exports = {
  ensureExists,
  sanitizeFilename,
}