Demo: https://repl.it/@NegarJF/Queue

Queue.js

class Queue {
  constructor(){
    this.head = null;
    this.tail = null;
    this.size = 0;
  }

  get length(){
    return this.size;
  }

  get peek(){
    return this.head.data;
  }

  add(data){
    const node = new Node(data);

    if(this.tail){
      this.tail.next = node;
    }

    this.tail = node;

    if(!this.head){
      this.head = node;
    }

    this.size++;
  }

  remove(){
    const data = this.head.data;
    this.head = this.head.next;
    this.size--;

    if(!this.head){
      this.tail = null;
    }

    return data;
  }
}


class Node {
  constructor(data){
    this.data = data;
    this.next = null;
  }
}


module.exports = Queue;