promise-polyfiller

    6.0.2 • Public • Published
    Promises/A+ logo # Promise Polyfill [![travis][travis-image]][travis-url]

    Lightweight ES6 Promise polyfill for the browser and node. Adheres closely to the spec. It is a perfect polyfill IE, Firefox or any other browser that does not support native promises.

    For API information about Promises, please check out this article HTML5Rocks article.

    It is extremely lightweight. < 1kb Gzipped

    Browser Support

    IE8+, Chrome, Firefox, IOS 4+, Safari 5+, Opera

    NPM Use

    npm install promise-polyfill --save-exact
    

    Bower Use

    bower install promise-polyfill
    

    Downloads

    Simple use

    import Promise from 'promise-polyfill'; 
     
    // To add to window
    if (!window.Promise) {
      window.Promise = Promise;
    }

    then you can use like normal Promises

    var prom = new Promise(function(resolve, reject) {
      // do a thing, possibly async, then…
     
      if (/* everything turned out fine */) {
        resolve("Stuff worked!");
      }  else {
        reject(new Error("It broke"));
      }
    });
     
    prom.then(function(result) {
      // Do something when async done
    });

    Deprecations

    • Promise._setImmediateFn(<immediateFn>) has been deprecated. Use Promise._immediateFn = <immediateFn>; instead.
    • Promise._setUnhandledRejectionFn(<rejectionFn>) has been deprecated. Use Promise._unhandledRejectionFn = <rejectionFn> instead. These functions will be removed in the next major version.

    Performance

    By default promise-polyfill uses setImmediate, but falls back to setTimeout for executing asynchronously. If a browser does not support setImmediate (IE/Edge are the only browsers with setImmediate), you may see performance issues. Use a setImmediate polyfill to fix this issue. setAsap or setImmediate work well.

    If you polyfill window.setImmediate or use Promise._immediateFn = yourImmediateFn it will be used instead of window.setTimeout

    npm install setasap --save
    
    var Promise = require('promise-polyfill');
    var setAsap = require('setasap');
    Promise._immediateFn = setAsap;

    Unhandled Rejections

    promise-polyfill will warn you about possibly unhandled rejections. It will show a console warning if a Promise is rejected, but no .catch is used. You can turn off this behavior by setting Promise._setUnhandledRejectionFn(<rejectError>). If you would like to disable unhandled rejections. Use a noop like below.

    Promise._unhandledRejectionFn = function(rejectError) {};

    Testing

    npm install
    npm test
    

    License

    MIT

    Install

    npm i promise-polyfiller

    DownloadsWeekly Downloads

    1

    Version

    6.0.2

    License

    MIT

    Last publish

    Collaborators

    • mattmueller