Javascript linked list class

linked-list.js

class LinkedList {
  constructor(initialElement) {
    this.length = 1;
    this.head = initialElement;
    this.head.next = this.head;
    this.head.prev = this.head;
  }

  // Just to be nice.
  value() {
    return this.head;
  }

  addAfter(element) {
    this.head.next.prev = element;
    element.prev = this.head;
    element.next = this.head.next;
    this.head.next = element;
    this.length++;
  }

  addBefore(element) {
    this.head.prev.next = element;
    element.prev = this.head.prev;
    element.next = this.head;
    this.head.prev = element;
    this.length++;
  }

  delete(shiftForward = false) {
    // Guard clause: No 0-length list!
    if (this.length == 1) return;

    let removed = this.head;
    removed.prev.next = removed.next;
    removed.next.prev = removed.prev;

    if (shiftForward) this.head = removed.prev;
    else this.head = removed.next;

    removed = null;
    this.length--;
  }

  next(count = 1) {
    while (count-- > 0) this.head = this.head.next;
  }

  prev(count = 1) {
    while (count-- > 0) this.head = this.head.prev;
  }
}

export default LinkedList;