export function hasClass(obj: HTMLElement, cls: string) {
  return obj.className.match(new RegExp("(\\s|^)" + cls + "(\\s|$)"))
}

export function removeClass(obj: HTMLElement, cls: string) {
  if (hasClass(obj, cls)) {
    const reg = new RegExp("(\\s|^)" + cls + "(\\s|$)")
    obj.className = obj.className.replace(reg, " ")
  }
}

export function addClass(obj: HTMLElement, cls: string) {
  if (!hasClass(obj, cls)) {
    obj.className === "" ? obj.className = `${cls}` : obj.className += ` ${cls}`
  }
}