hexo/node_modules/core-js/modules/_array-includes.js

// false -> Array#indexOf
// true  -> Array#includes
var toIObject = require('./_to-iobject');
var toLength = require('./_to-length');
var toAbsoluteIndex = require('./_to-absolute-index');
module.exports = function (IS_INCLUDES) {
  return function ($this, el, fromIndex) {
    var O = toIObject($this);
    var length = toLength(O.length);
    var index = toAbsoluteIndex(fromIndex, length);
    var value;
    // Array#includes uses SameValueZero equality algorithm
    // eslint-disable-next-line no-self-compare
    if (IS_INCLUDES && el != el) while (length > index) {
      value = O[index++];
      // eslint-disable-next-line no-self-compare
      if (value != value) return true;
    // Array#indexOf ignores holes, Array#includes - not
    } else for (;length > index; index++) if (IS_INCLUDES || index in O) {
      if (O[index] === el) return IS_INCLUDES || index || 0;
    } return !IS_INCLUDES && -1;
  };
};