Sanitize string & filename

sanitize.js

const _ = require('lodash')

const sanitize = str => _.chain(str)
  .replace(/[^A-Za-z0-9&.-]/g, '-') // sanitise via whitelist of characters
  .replace(/-(?=-)/g, '') // remove repeated dashes - https://regexr.com/6ag8h
  .trim('-') // trim any leading/trailing dashes
  .truncate({
    length: 40, // max length
    omission: '-' // when the string ends with '-', you'll know it was truncated
  })
  .value()

const sanitizeFilename = filename => {    
    // sanitize filename but keep extension
    const filename_parts = filename.split('.')
    const ext = _.slice(filename_parts, filename_parts.length-1)
    const filename_main = _.join(_.dropRight(filename_parts), '.')
    return sanitize(filename_main) + '.' + ext
}