export function hasClass(el, className) {

  let reg = new RegExp('(^|\\s)' + className + '(\\s|$)')

  return reg.test(el.className)

}

export function addClass(el, className) {

  if (hasClass(el, className)) {

    return

  }

  let newClass = el.className.split(' ')

  newClass.push(className)

  el.className = newClass.join(' ')

}