Lightweight promise polyfill. A+ compliant
npm install promise-polyfillLightweight ES6 Promise polyfill for the browser and node. Adheres closely to
the spec. It is a perfect polyfill IE 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_
IE8+, Chrome, Firefox, IOS 4+, Safari 5+, Opera
``
npm install promise-polyfill --save-exact
`
bower install promise-polyfill
This will set a global Promise object if the browser doesn't already have window.Promise.
`html`
If you would like to add a global Promise object (Node or Browser) if native Promise doesn't exist (polyfill Promise). Use the method below. This is useful if you are building a website and want to support older browsers.
Javascript library authors should _NOT_ use this method.
`js`
import 'promise-polyfill/src/polyfill';
If you would like to not affect the global environment (sometimes known as a ponyfill, you can import the base module. This is nice for library authors or people working in environment where you don't want
to affect the global environment.
`js`
import Promise from 'promise-polyfill';
If using require with Webpack 2+ (rare), you need to specify the default import
`js`
var Promise = require('promise-polyfill').default;
then you can use like normal Promises
`js
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
});
`
By default promise-polyfill uses setImmediate, but falls back to setTimeout
for executing asynchronously. If a browser does not support
(IE/Edge are the only browsers with setImmediate), you may see performance
issues. Use a 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
`js`
import Promise from 'promise-polyfill/src/polyfill';
import setAsap from 'setasap';
Promise._immediateFn = setAsap;
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
change this behavior by doing.
-NOTE: This only works on promise-polyfill Promises. Native Promises do not support this function
`js`
Promise._unhandledRejectionFn =
If you would like to disable unhandled rejection messages. Use a noop like
below.
`js`
Promise._unhandledRejectionFn = function(rejectError) {};
`
npm install
npm test
MIT