https://github.com/ljharb/promiseback
Accept an optional node-style callback, and also return a spec-compliant Promise!
https://github.com/ljharb/promiseback
Last synced: 6 months ago
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Accept an optional node-style callback, and also return a spec-compliant Promise!
- Host: GitHub
- URL: https://github.com/ljharb/promiseback
- Owner: ljharb
- License: mit
- Created: 2013-12-30T01:29:04.000Z (almost 12 years ago)
- Default Branch: main
- Last Pushed: 2022-10-28T03:47:51.000Z (almost 3 years ago)
- Last Synced: 2025-03-29T08:01:33.947Z (7 months ago)
- Language: JavaScript
- Homepage:
- Size: 50.8 KB
- Stars: 10
- Watchers: 2
- Forks: 0
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
#promiseback [![Version Badge][npm-version-svg]][npm-url]
[![Build Status][travis-svg]][travis-url]
[![dependency status][deps-svg]][deps-url]
[![dev dependency status][dev-deps-svg]][dev-deps-url]
[![npm badge][npm-badge-png]][npm-url]
[![browser support][testling-png]][testling-url]
Accept an optional node-style callback, and also return a spec-compliant Promise!
## API
```js
var promiseback = require('promiseback');
var callback = function (err, value) {};
/* without a promise: */
promiseback(callback);
/*
- will throw if `callback` is not a function
- returns a "deferred"
- has resolve/reject methods, and `promise` property
- will call `callback` as expected when deferred is resolved
*/
/* with a promise: */
promiseback(promise, callback);
/*
- will throw if `callback` is truthy and not a function
- `promise` will be converted to a Promise, so you can pass a value as well
- returns a Promise
- will call `callback` as expected when the promise is fulfilled
*/
```
## Examples
Using deferreds:
```js
var promiseback = require('promiseback');
module.exports = function doSomethingCool(thing, callback) {
// If callback is not provided, this code will simply return a normal promise.
// If callback is provided but is not a function, promiseback will immediately throw a TypeError.
// "deferred" is an object with `reject/resolve` methods, and a `promise` property.
var deferred = promiseback(callback);
if (thing) {
deferred.resolve(thing);
} else {
deferred.reject(thing);
}
return deferred.promise;
};
```
Using a straight promise, when you can get it from somewhere else:
```js
var promiseback = require('promiseback');
module.exports = function doSomethingCool(thing, callback) {
// If callback is not provided, this code will simply return a normal promise.
// If callback is provided but is not a function, promiseback will immediately throw a TypeError.
var newThingPromise = makeNewThing(thing);
return promiseback(newThingPromise, callback);
};
```
## Tests
Simply clone the repo, `npm install`, and run `npm test`
[npm-url]: https://npmjs.org/package/promiseback
[npm-version-svg]: http://versionbadg.es/ljharb/promiseback.svg
[travis-svg]: https://travis-ci.org/ljharb/promiseback.svg
[travis-url]: https://travis-ci.org/ljharb/promiseback
[deps-svg]: https://david-dm.org/ljharb/promiseback.svg
[deps-url]: https://david-dm.org/ljharb/promiseback
[dev-deps-svg]: https://david-dm.org/ljharb/promiseback/dev-status.svg
[dev-deps-url]: https://david-dm.org/ljharb/promiseback#info=devDependencies
[testling-png]: https://ci.testling.com/ljharb/promiseback.png
[testling-url]: https://ci.testling.com/ljharb/promiseback
[npm-badge-png]: https://nodei.co/npm/promiseback.png?downloads=true&stars=true