https://github.com/hybridables/then-callback
Wrap a promise to allow passing callback to `.then` of given promise, also works as normal `.then`
https://github.com/hybridables/then-callback
Last synced: 3 months ago
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Wrap a promise to allow passing callback to `.then` of given promise, also works as normal `.then`
- Host: GitHub
- URL: https://github.com/hybridables/then-callback
- Owner: hybridables
- License: mit
- Created: 2015-10-10T19:59:25.000Z (over 9 years ago)
- Default Branch: master
- Last Pushed: 2017-04-05T23:21:21.000Z (about 8 years ago)
- Last Synced: 2025-02-17T08:16:40.347Z (4 months ago)
- Language: JavaScript
- Homepage:
- Size: 13.7 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Awesome Lists containing this project
README
# [then-callback][author-www-url] [![npmjs.com][npmjs-img]][npmjs-url] [![The MIT License][license-img]][license-url]
> Wrap a promise to allow passing callback to `.then` of given promise, also works as normal `.then`
[![code climate][codeclimate-img]][codeclimate-url] [![standard code style][standard-img]][standard-url] [![travis build status][travis-img]][travis-url] [![coverage status][coveralls-img]][coveralls-url] [![dependency status][david-img]][david-url]
## Install
```
npm i then-callback --save
```
## Usage
> For more use-cases see the [tests](./test.js)
### [thenCallback](./index.js#L43)
> Basically, you just pass a promise and it returns promise, but `.then` from the returned promise can accept a callback function, instead of two arguments as usual - one for result, one for error.
Notice that it also works as normal `.then` if you pass two arguments.
- `` **{Promise}**
- `return` **{Promise}**
**Example**
```js
const thenCallback = require('then-callback')
const promise = Promise.resolve(123)
thenCallback(promise).then((err, res) => {
console.log('err:', err) // => null
console.log('res:', res) // => 123
})
// but also works as normal `.then`
thenCallback(promise).then((res) => {
console.log('res:', res) // => 123
}, (err) => {
console.log('err:', err)
})
```
You just need to wrap a promise, then you can use `.then` as usual, or to pass callback-style function to it as first argument.
**Example**
```js
const fs = require('fs')
const redolent = require('redolent')
const readFile = redolent(fs.readFile)
const thenCallback = require('then-callback')
const thenCallback = require('then-callback')
var promise = readFile('package.json', 'utf8')
promise = thenCallback(promise)
promise.then((err, res) => {
if (err) return console.error(err)
console.log(JSON.parse(res).name) //=> 'then-callback'
})
```
Otherwise, if you pass two arguments and second is function, it will work as normal `.then`.
**Example**
```js
const thenCallback = require('then-callback')
const NativePromise = require('native-or-another')()
// rejected promise
var promise = NativePromise.reject(new Error('foo bar'))
thenCallback(promise).then(console.log, console.error) //=> Error: foo bar
// resolved promise
var promise = NativePromise.resolve(123)
thenCallback(promise).then(console.log, console.error) //=> '123'
```
## Related
- [always-promise](https://github.com/hybridables/always-promise): Promisify, basically, everything. Generator function, callback-style or synchronous function; sync function that returns child process, stream or observable; directly passed promise, stream or child process.
- [letta](https://github.com/hybridables/letta): Let's move to promises! Drop-in replacement for `co@4`, but on steroids. Accepts sync, async and generator functions.
- [native-or-another](https://github.com/tunnckoCore/native-or-another): Always will expose native `Promise` if available, otherwise `Bluebird` but only if you don't give another promise module like `q` or `promise` or what you want.
- [native-promise](https://github.com/tunnckoCore/native-promise): Get native `Promise` or falsey value if not available.
## Contributing
Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/hybridables/then-callback/issues/new).
But before doing anything, please read the [CONTRIBUTING.md](./CONTRIBUTING.md) guidelines.
## [Charlike Make Reagent](http://j.mp/1stW47C) [![new message to charlike][new-message-img]][new-message-url] [![freenode #charlike][freenode-img]][freenode-url]
[![tunnckocore.tk][author-www-img]][author-www-url] [![keybase tunnckocore][keybase-img]][keybase-url] [![tunnckoCore npm][author-npm-img]][author-npm-url] [![tunnckoCore twitter][author-twitter-img]][author-twitter-url] [![tunnckoCore github][author-github-img]][author-github-url]
[npmjs-url]: https://www.npmjs.com/package/then-callback
[npmjs-img]: https://img.shields.io/npm/v/then-callback.svg?label=then-callback
[license-url]: https://github.com/hybridables/then-callback/blob/master/LICENSE.md
[license-img]: https://img.shields.io/badge/license-MIT-blue.svg
[codeclimate-url]: https://codeclimate.com/github/hybridables/then-callback
[codeclimate-img]: https://img.shields.io/codeclimate/github/hybridables/then-callback.svg
[travis-url]: https://travis-ci.org/hybridables/then-callback
[travis-img]: https://img.shields.io/travis/hybridables/then-callback.svg
[coveralls-url]: https://coveralls.io/r/hybridables/then-callback
[coveralls-img]: https://img.shields.io/coveralls/hybridables/then-callback.svg
[david-url]: https://david-dm.org/hybridables/then-callback
[david-img]: https://img.shields.io/david/hybridables/then-callback.svg
[standard-url]: https://github.com/feross/standard
[standard-img]: https://img.shields.io/badge/code%20style-standard-brightgreen.svg
[author-www-url]: http://www.tunnckocore.tk
[author-www-img]: https://img.shields.io/badge/www-tunnckocore.tk-fe7d37.svg
[keybase-url]: https://keybase.io/tunnckocore
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[author-npm-url]: https://www.npmjs.com/~tunnckocore
[author-npm-img]: https://img.shields.io/badge/npm-~tunnckocore-cb3837.svg
[author-twitter-url]: https://twitter.com/tunnckoCore
[author-twitter-img]: https://img.shields.io/badge/[email protected]
[author-github-url]: https://github.com/tunnckoCore
[author-github-img]: https://img.shields.io/badge/[email protected]
[freenode-url]: http://webchat.freenode.net/?channels=charlike
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[new-message-url]: https://github.com/tunnckoCore/ama
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