ES6-Promise (subset of rsvp.js) #
This is a polyfill of the ES6 Promise. The implementation is a subset of rsvp.js extracted by @jakearchibald, if you're wanting extra features and more debugging options, check out the full library.
For API details and how to use promises, see the JavaScript Promises HTML5Rocks article.
Downloads#
- es6-promise 27.86 KB (7.33 KB gzipped)
- es6-promise-auto 27.78 KB (7.3 KB gzipped) - Automatically provides/replaces
Promise
if missing or broken. - es6-promise-min 6.17 KB (2.4 KB gzipped)
- es6-promise-auto-min 6.19 KB (2.4 KB gzipped) - Minified version of
es6-promise-auto
above.
CDN#
To use via a CDN include this in your html:
<!-- Automatically provides/replaces `Promise` if missing or broken. -->
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.js"></script>
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.auto.js"></script>
<!-- Minified version of `es6-promise-auto` below. -->
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.auto.min.js"></script>
Node.js#
To install:
yarn add es6-promise
or
npm install es6-promise
To use:
var Promise = require('es6-promise').Promise;
Usage in IE<9#
catch
and finally
are reserved keywords in IE<9, meaningpromise.catch(func)
or promise.finally(func)
throw a syntax error. To work
around this, you can use a string to access the property as shown in the
following example.
However most minifiers will automatically fix this for you, making the
resulting code safe for old browsers and production:
promise['catch'](function(err) {
// ...
});
promise['finally'](function() {
// ...
});
Auto-polyfill#
To polyfill the global environment (either in Node or in the browser via CommonJS) use the following code snippet:
require('es6-promise').polyfill();
Alternatively
require('es6-promise/auto');
Notice that we don't assign the result of polyfill()
to any variable. The polyfill()
method will patch the global environment (in this case to the Promise
name) when called.
Building & Testing#
You will need to have PhantomJS installed globally in order to run the tests.
npm install -g phantomjs
npm run build
to buildnpm test
to run testsnpm start
to run a build watcher, and webserver to testnpm run test:server
for a testem test runner and watching builder