core-js/internals/get-set-record.js

'use strict';
var aCallable = require('../internals/a-callable');
var anObject = require('../internals/an-object');
var call = require('../internals/function-call');
var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
var getIteratorDirect = require('../internals/get-iterator-direct');

var INVALID_SIZE = 'Invalid size';
var $RangeError = RangeError;
var $TypeError = TypeError;
var max = Math.max;

var SetRecord = function (set, intSize) {
  this.set = set;
  this.size = max(intSize, 0);
  this.has = aCallable(set.has);
  this.keys = aCallable(set.keys);
};

SetRecord.prototype = {
  getIterator: function () {
    return getIteratorDirect(anObject(call(this.keys, this.set)));
  },
  includes: function (it) {
    return call(this.has, this.set, it);
  }
};

// `GetSetRecord` abstract operation
// https://tc39.es/proposal-set-methods/#sec-getsetrecord
module.exports = function (obj) {
  anObject(obj);
  var numSize = +obj.size;
  // NOTE: If size is undefined, then numSize will be NaN
  // eslint-disable-next-line no-self-compare -- NaN check
  if (numSize !== numSize) throw new $TypeError(INVALID_SIZE);
  var intSize = toIntegerOrInfinity(numSize);
  if (intSize < 0) throw new $RangeError(INVALID_SIZE);
  return new SetRecord(obj, intSize);
};