var $ = require('../internals/export');
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-isfrozen -- safe
var $isFrozen = Object.isFrozen;
var FAILS_ON_PRIMITIVES = fails(function () { $isFrozen(1); });

// `Object.isFrozen` method
// https://tc39.es/ecma262/#sec-object.isfrozen
$({ target: 'Object', stat: true, forced: FAILS_ON_PRIMITIVES || ARRAY_BUFFER_NON_EXTENSIBLE }, {
  isFrozen: function isFrozen(it) {
    if (!isObject(it)) return true;
    if (ARRAY_BUFFER_NON_EXTENSIBLE && classof(it) == 'ArrayBuffer') return true;
    return $isFrozen ? $isFrozen(it) : false;
  }
});