iopa-bot/src/polyfill/array.ts

API-First Bot Framework for Internet of Things (IoT), based on Internet of Protocols Alliance (IOPA) specification

/** ES6 Array Polyfill */
if (!Array.prototype.includes) {
  Object.defineProperty(Array.prototype, 'includes', {
    enumerable: false,
    value: function(searchElement) {
      'use strict'
      if (this == null) {
        throw new TypeError(
          'Array.prototype.includes called on null or undefined'
        )
      }

      var O = Object(this)
      var len = parseInt(O.length, 10) || 0
      if (len === 0) {
        return false
      }
      var n = parseInt(arguments[1], 10) || 0
      var k
      if (n >= 0) {
        k = n
      } else {
        k = len + n
        if (k < 0) {
          k = 0
        }
      }
      var currentElement
      while (k < len) {
        currentElement = O[k]
        if (
          searchElement === currentElement ||
          (searchElement !== searchElement && currentElement !== currentElement)
        ) {
          // NaN !== NaN
          return true
        }
        k++
      }
      return false
    }
  })
}