| # ES6-Promise (subset of [rsvp.js](https://github.com/tildeio/rsvp.js)) [](https://travis-ci.org/stefanpenner/es6-promise) |
| |
| This is a polyfill of the [ES6 Promise](http://www.ecma-international.org/ecma-262/6.0/#sec-promise-constructor). The implementation is a subset of [rsvp.js](https://github.com/tildeio/rsvp.js) extracted by @jakearchibald, if you're wanting extra features and more debugging options, check out the [full library](https://github.com/tildeio/rsvp.js). |
| |
| For API details and how to use promises, see the <a href="http://www.html5rocks.com/en/tutorials/es6/promises/">JavaScript Promises HTML5Rocks article</a>. |
| |
| ## Downloads |
| |
| * [es6-promise 27.86 KB (7.33 KB gzipped)](https://cdn.jsdelivr.net/npm/es6-promise/dist/es6-promise.js) |
| * [es6-promise-auto 27.78 KB (7.3 KB gzipped)](https://cdn.jsdelivr.net/npm/es6-promise/dist/es6-promise.auto.js) - Automatically provides/replaces `Promise` if missing or broken. |
| * [es6-promise-min 6.17 KB (2.4 KB gzipped)](https://cdn.jsdelivr.net/npm/es6-promise/dist/es6-promise.min.js) |
| * [es6-promise-auto-min 6.19 KB (2.4 KB gzipped)](https://cdn.jsdelivr.net/npm/es6-promise/dist/es6-promise.auto.min.js) - Minified version of `es6-promise-auto` above. |
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| ## CDN |
| |
| To use via a CDN include this in your html: |
| |
| ```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 |
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| To install: |
| |
| ```sh |
| yarn add es6-promise |
| ``` |
| |
| or |
| |
| ```sh |
| npm install es6-promise |
| ``` |
| |
| To use: |
| |
| ```js |
| var Promise = require('es6-promise').Promise; |
| ``` |
| |
| |
| ## Usage in IE<9 |
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| `catch` and `finally` are reserved keywords in IE<9, meaning |
| `promise.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: |
| |
| ```js |
| promise['catch'](function(err) { |
| // ... |
| }); |
| ``` |
| |
| ```js |
| promise['finally'](function() { |
| // ... |
| }); |
| ``` |
| |
| ## Auto-polyfill |
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| To polyfill the global environment (either in Node or in the browser via CommonJS) use the following code snippet: |
| |
| ```js |
| require('es6-promise').polyfill(); |
| ``` |
| |
| Alternatively |
| |
| ```js |
| 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 |
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| You will need to have PhantomJS installed globally in order to run the tests. |
| |
| `npm install -g phantomjs` |
| |
| * `npm run build` to build |
| * `npm test` to run tests |
| * `npm start` to run a build watcher, and webserver to test |
| * `npm run test:server` for a testem test runner and watching builder |