index.js

class Draggable {

   constructor() {
       this.container = document.querySelector('.box__dragabble');
       this.box = document.querySelectorAll('.box');
       
       this._addEventListener();
   }

   _addEventListener() {
       this.box.forEach(element => {
           element.addEventListener('dragenter', this.dragenter)
           element.addEventListener('dragleave', this.dragleave)
           element.addEventListener('dragover', this.dragover)
           element.addEventListener('drop', this.drop)
       });

       this.container.addEventListener('dragstart', this.dragstart);
       this.container.addEventListener('dragend', this.dragend);
   }

   dragstart(e) {
       this.classList.add('drag_start');
      setTimeout(() => {
         this.classList.add('invisible');
      }, 0);
   }

   dragend(e) {
       console.log('dragend')
       this.classList.remove('invisible');
       this.classList.remove('drag_start');
   }

   dragenter(e) {
       e.preventDefault();
       
       console.log('dragenter')
        this.classList.add('drag_enter');
   }

   dragleave(e) {
       console.log('dragleave')
       this.classList.remove('drag_enter');
   }

   dragover(e) {
       e.preventDefault();
       console.log('dragover')
   }

   drop() {
        let container = document.querySelector('.box__dragabble');
        this.classList.remove('drag_enter')
       this.append(container)
   }

   static init() {
       return new this();
   }
}


document
    .addEventListener('load', Draggable.init());