JavaScript Linked List Implementation

linkedlist.js

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

class LinkedList {
  constructor() {
    this.head = null;
    this.tail = null;
  }
  
  add(data) {
    let n = new Node(data);

    if(!this.head) {
      this.head = n;
      this.tail = n;
    } else {
      this.tail.next = n;
      this.tail = n;
      return n;
    }
  }
  
  delete(node) {
    let n = this.head;

    if(node === this.head){
      if(this.head === this.tail) {
        this.head = null;
        this.tail = null;
      } else {
        this.head = this.head.next;
        return;
      }
    }

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

  }
}

//Sample Usage:
let ll = new LinkedList();
let a = ll.add('a');
let b = ll.add('b');
let c = ll.add('c');
let d = ll.add('d');
console.log(ll.tail);