A missing queue implementation for JavaScript, implemented with a linked list

queue.js

/**
 * Simple Queue implementation based on a linked-list
 */
class Q {
  /**
   * Construct a queue
   * @param {array} [items] - Items to put in the queue (in left-to-right order)
   */
  constructor(items) {
    this._size = 0
    this._head = null
    this._tail = null
    if (items) {
      this.enqueue(...items)
    }
  }
  /**
   * Elements currently in queue
   */
  get size() {
    return this._size
  }
  /**
   * Add item(s) to queue
   * @param {...*} items - Items to put in the queue (in left-to-right order)
   */
  enqueue(...items) {
    for (let item of items) {
      if (!this._tail){
        this._tail = this._head = { item, next: null}
      } else {
        this._tail.next = { item, next: null}
        this._tail = this._tail.next
      }
      this._size++
    }
  }
  /**
   * Remove item in FIFO order
   * @return {*} item
   * @throws {Error} Queue must not be empty
   */
  dequeue() {
    if (!this._size) {
      throw new Error("queue is empty")
    }
    let result = this._head.item
    this._head = this._head.next
    this._size--
    if (this._head === null) {
      this._tail = null
    }
    return result
  }
  /** for debugging in node */
  inspect() {
    let node = this._head
    let items = []
    while (node) {
      items.push(node.item)
      node = node.next
    }
    return `queue -> ${items.map(i => require('util').inspect(i)).join(',')} ->`
  }
}