es.array.filter.js

'use strict';
var $ = require('../internals/export');
var $filter = require('../internals/array-iteration').filter;
var fails = require('../internals/fails');
var arrayMethodHasSpeciesSupport = require('../internals/array-method-has-species-support');

var HAS_SPECIES_SUPPORT = arrayMethodHasSpeciesSupport('filter');
// Edge 14- issue
var USES_TO_LENGTH = HAS_SPECIES_SUPPORT && !fails(function () {
  [].filter.call({ length: -1, 0: 1 }, function (it) { throw it; });
});

// `Array.prototype.filter` method
// https://tc39.github.io/ecma262/#sec-array.prototype.filter
// with adding support of @@species
$({ target: 'Array', proto: true, forced: !HAS_SPECIES_SUPPORT || !USES_TO_LENGTH }, {
  filter: function filter(callbackfn /* , thisArg */) {
    return $filter(this, callbackfn, arguments.length > 1 ? arguments[1] : undefined);
  }
});