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🚀 Dojo 2 - provides modular fills of ES6+ functionality.
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The @dojo/shim repository has been deprecated and merged into @dojo/framework

You can read more about this change on our blog. We will continue providing patches for shim and other Dojo 2 repositories, and a CLI migration tool is available to aid in migrating projects from v2 to v3.


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This package provides functional shims for ECMAScript, access to the Typescript helpers, and a quick way to include the polyfills needed to run Dojo 2 in the browser.

It is targeted at providing function shims for ECMAScript 6 and beyond targeted at ECMAScript 5. It is different than other solutions of shimming or polyfilling functionality, in that it does not provide the functionality via augmenting the built-in classes in the global namespace.

There are two exceptions to this. One is the Promise object, which needs to be globally available for async/await operations. The other exception is the Symbol functionality, in that the well-known symbols need to be located off of the global Symbol object in order to ensure that the correct symbol is referenced.


To use @dojo/shim, install the package along with its required peer dependencies:

npm install @dojo/shim

# peer dependencies
npm install @dojo/has

Include the module in your project to load the global shims and Typescript helpers.

import '@dojo/shim';

Since the main module loads the Typescript helpers, you'll want to turn off helper generation in your project. Add the following option to your tsconfig.json.

	"compilerOptions": {
		"noEmitHelpers": true

If you are using Dojo 2 in the browser, you will want to load the browser polyfills. These are available by simply importing the @dojo/shim/browser module.

// load polyfills for features used by Dojo 2
import '@dojo/shim/browser';

Note: Other Dojo 2 packages will include these dependencies. You only need to worry about this if you are using this package stand alone.


Many of the features in this package will fallback to a native implementation if one is available.

Array Methods

@dojo/shim/array provides implementations of many array utilities.

Data Structures


The @dojo/shim/Map class is an implementation of the ES2015 Map specification without iterators for use in older browsers.


The @dojo/shim/Set class is an implementation of the ES2015 Set specification. A Set is used to create a collection of unique values.

import Set from '@dojo/shim/Set';

const values = new Set<string>();

values.forEach((value) => {

// output:
// one
// two


The @dojo/shim/WeakMap class is an implementation of the ES2015 WeakMap specification without iterators for use in older browsers. The main difference between WeakMap and Map is that WeakMap's keys can only be objects and that the store has a weak reference to the key/value pair. This allows for the garbage collector to remove pairs.

See the Map documentation for more information on how to use WeakMap.


The @dojo/shim/iterator module is an implementation of the ES2015 Iterator specification.


The @dojo/shim/math module provides implementations for many math methods.


The dojo/shim/number module provides implementations for several Number methods.

  • isNaN
  • isFinite
  • isInteger
  • isSafeInteger


The dojo/shim/object provides implementations of Object methods.

  • is
  • getOwnPropertySymbols
  • getOwnPropertyNames
  • getOwnPropertyDescriptor
  • values
  • entries


The @dojo/shim/Observable class is an implementation of the proposed Observable specification. Observables are further extended in @dojo/core/Observable.


@dojo/shim/Promise is an implementation of the ES2015 Promise specification.


The @dojo/shim/string module contains String methods.


@dojo/shim/Symbol provides an implementation of the ES2015 Symbol specification for environments that do not natively support Symbol.

Licensing information

© 2018 JS Foundation & contributors. New BSD license.