packages/core-js/modules/esnext.array.is-template-object.js

'use strict';
var $ = require('../internals/export');
var isArray = require('../internals/is-array');

// eslint-disable-next-line es/no-object-isfrozen -- safe
var isFrozen = Object.isFrozen;

var isFrozenStringArray = function (array, allowUndefined) {
  if (!isFrozen || !isArray(array) || !isFrozen(array)) return false;
  var index = 0;
  var length = array.length;
  var element;
  while (index < length) {
    element = array[index++];
    if (!(typeof element == 'string' || (allowUndefined && element === undefined))) {
      return false;
    }
  } return length !== 0;
};

// `Array.isTemplateObject` method
// https://github.com/tc39/proposal-array-is-template-object
$({ target: 'Array', stat: true, sham: true, forced: true }, {
  isTemplateObject: function isTemplateObject(value) {
    if (!isFrozenStringArray(value, true)) return false;
    var raw = value.raw;
    return raw.length === value.length && isFrozenStringArray(raw, false);
  }
});