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0.0.1 • Public • Published


NOTE: This is a fork of extendscript-es5-shim. I have only added the types and a JSON shim

A collection of ES5 shims for polyfiling Exendscript (for es6 shims take a look at https://github.com/ExtendScript/extendscript-es6-shim)


npm init -y
npm install extendscript-es5-shim-ts


Array, String and Function notes

All polyfills could be used in your code.

Object notes

Because it is impossible to emulate property descriptors in ES3 engine, the following functions are just a mocks and you should avoid to use them in your code if it is possible, only shim thirdparty libraries:

defineProperty, defineProperties

Supports only data descriptor. Writable, enumerable and configurable properties of descriptor are ignored. If you try to define set or get propperty this methods will throw an error.


Supports only data descriptor. Configurable property of descriptor is always TRUE. Enumerable and writable properties of descriptor will be always TRUE on user defined objects, but may vary on build in.

freeze, preventExtensions, seal

Only validate input parameter and return input if it is an object.

isExtensible, isFrozen, isSealed

Validates input and returns TRUE, FALSE, FALSE, respectively if input parametr is an object.

These functions you can use in your code:


Support of property descriptor is in the same level as in defineProperty. Although, you can use this function in your code like this:

var obj1 = {: 1};
var obj2 = Object.create(obj1, {: {value : 2}});

or like that:

var obj1 = {: 1};
var obj2 = Object.create(obj1);
obj2.b = 2;


This function uses reflection interface, that ExtendScript provides (see JavaScript Tools Guide), to get own properties of an object (enumerable or not). But ther is no guarantee that the order of enumeration will be the same as in for in loop.


Use for in loop along with hasOwnProperty function to get own enumerable properties in object.


Use build in __proto__ property as return value.


  • Install the devDependencies by running npm install
  • Bundle the index.js by running npm run bundle
  • Add new prototypes in the respective folders
  • If you need new folders, add the folder to the top of ./bin/concat.js into the folders array

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