is-circular/lib/node.js

high-performance, zero-dependency circular reference check for objects (or arrays)

module.exports = Node

/**
 * a linked-list node
 * @class
 * @param {any} value - node's value
 * @param {Node} next - next node
 */
function Node (value, next) {
  this.value = value
  this.next = next
}

/**
 * checks if this node or any of its children has the value
 * @param {any} value - value to check if linked-list contains
 * @return {boolean} true if the list contains the value; false if not
 */
Node.prototype.contains = function (value) {
  var cursor = this

  while (cursor) {
    if (cursor.value === value) return true
    cursor = cursor.next
  }

  return false
}