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    2.0.0 • Public • Published


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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.

    How do I contribute?

    We appreciate your interest! Please see the Dojo 2 Meta Repository for the Contributing Guidelines.

    Code Style

    This repository uses prettier for code styling rules and formatting. A pre-commit hook is installed automatically and configured to run prettier against all staged files as per the configuration in the project's package.json.

    An additional npm script to run prettier (with write set to true) against all src and test project files is available by running:

    npm run prettier


    To start working with this package, clone the repository and run npm install.

    In order to build the project run grunt dev or grunt dist.


    Test cases MUST be written using Intern using the Object test interface and Assert assertion interface.

    90% branch coverage MUST be provided for all code submitted to this repository, as reported by istanbul’s combined coverage results for all supported platforms.

    To test locally in node run:

    grunt test

    To test against browsers with a local selenium server run:

    grunt test:local

    To test against BrowserStack or Sauce Labs run:

    grunt test:browserstack


    grunt test:saucelabs

    Licensing information

    © 2018 JS Foundation & contributors. New BSD license.




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