JSPM – promise-polyfill@5.1.0

Package Exports

promise-polyfill
promise-polyfill/promise
promise-polyfill/promise.min.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (promise-polyfill) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

# Promise [![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

Downloads

Node

npm install promise-polyfill

Bower

bower install promise-polyfill

Simple use

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
});

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._setImmediateFn(immedateFn) it will be used instead of window.setTimeout

npm install setasap --save

var Promise = require('promise-polyfill');
var setAsap = require('setasap');
Promise._setImmediateFn(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._setUnhandledRejectionFn(function(rejectError) {});

Testing

npm install
npm test

License

MIT