core-js/internals/object-is-extensible.js

'use strict';
var fails = require('../internals/fails');
var isObject = require('../internals/is-object');
var classof = require('../internals/classof-raw');
var ARRAY_BUFFER_NON_EXTENSIBLE = require('../internals/array-buffer-non-extensible');

// eslint-disable-next-line es/no-object-isextensible -- safe
var $isExtensible = Object.isExtensible;
var FAILS_ON_PRIMITIVES = fails(function () { $isExtensible(1); });

// `Object.isExtensible` method
// https://tc39.es/ecma262/#sec-object.isextensible
module.exports = (FAILS_ON_PRIMITIVES || ARRAY_BUFFER_NON_EXTENSIBLE) ? function isExtensible(it) {
  if (!isObject(it)) return false;
  if (ARRAY_BUFFER_NON_EXTENSIBLE && classof(it) === 'ArrayBuffer') return false;
  return $isExtensible ? $isExtensible(it) : true;
} : $isExtensible;