Very simple class toggler

class-toggler.js

// =============
// CLASS TOGGLER
// =============
(function(){
  const togglers = document.querySelectorAll('.js-toggler');

  togglers.forEach(elm => {
    elm.addEventListener('click', toggleClass);
  });

  function toggleClass(e){
    const toggler = this;
    const tgt = toggler.getAttribute('data-toggler-target');
    const cls = toggler.getAttribute('data-toggler-class');

    document.querySelector(tgt).classList.toggle(cls);
  }
})();