node_modules.promise.lib.node-extensions.js Maven / Gradle / Ivy

'use strict';

//This file contains then/promise specific extensions that are only useful for node.js interop

var Promise = require('./core.js')
var asap = require('asap')

module.exports = Promise

/* Static Functions */

Promise.denodeify = function (fn, argumentCount) {
  argumentCount = argumentCount || Infinity
  return function () {
    var self = this
    var args = Array.prototype.slice.call(arguments)
    return new Promise(function (resolve, reject) {
      while (args.length && args.length > argumentCount) {
        args.pop()
      }
      args.push(function (err, res) {
        if (err) reject(err)
        else resolve(res)
      })
      var res = fn.apply(self, args)
      if (res && (typeof res === 'object' || typeof res === 'function') && typeof res.then === 'function') {
        resolve(res)
      }
    })
  }
}
Promise.nodeify = function (fn) {
  return function () {
    var args = Array.prototype.slice.call(arguments)
    var callback = typeof args[args.length - 1] === 'function' ? args.pop() : null
    var ctx = this
    try {
      return fn.apply(this, arguments).nodeify(callback, ctx)
    } catch (ex) {
      if (callback === null || typeof callback == 'undefined') {
        return new Promise(function (resolve, reject) { reject(ex) })
      } else {
        asap(function () {
          callback.call(ctx, ex)
        })
      }
    }
  }
}

Promise.prototype.nodeify = function (callback, ctx) {
  if (typeof callback != 'function') return this

  this.then(function (value) {
    asap(function () {
      callback.call(ctx, null, value)
    })
  }, function (err) {
    asap(function () {
      callback.call(ctx, err)
    })
  })
}