Promise-back NPM

promise-back

Augment a thunk such that it returns a promise if applied without a callback.

npm install promise-back --save

You can also use Duo, Bower or download the files manually.

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API Example

require

var promiseBack = require('promise-back')

expose dual interface async function

var read = require('fs').readFile
var path = require('path')
var filepath = path.resolve(__dirname, 'package.json')
var encoding = 'utf8'
var readable = promiseBack(read.bind(null, filepath, encoding))

NOTE: if you already have a function that takes a callback as it's only parameter, you can just pass it to promiseBack. Modules that expose such an interface can be passed directly to promiseBack without a wrapper; You may also use Function.prototype.bind to achieve the same.

use callback interface

readable(function (_, str) {
  console.log(JSON.parse(pkg).description)
})
//=> Augment a thunk such that it returns a promise if applied without a callback.

use promise interface

readable()
.then(JSON.parse)
.then(selectn('description'))
.then(console.log)
.catch(console.error)
//=> Augment a thunk such that it returns a promise if applied without a callback.