181 lines
4.5 KiB
JavaScript
181 lines
4.5 KiB
JavaScript
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'use strict';
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//This file contains then/promise specific extensions to the core promise API
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var Promise = require('./core.js')
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var asap = require('asap')
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module.exports = Promise
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/* Static Functions */
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function ValuePromise(value) {
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this.then = function (onFulfilled) {
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if (typeof onFulfilled !== 'function') return this
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return new Promise(function (resolve, reject) {
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asap(function () {
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try {
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resolve(onFulfilled(value))
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} catch (ex) {
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reject(ex);
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}
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})
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})
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}
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}
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ValuePromise.prototype = Object.create(Promise.prototype)
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var TRUE = new ValuePromise(true)
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var FALSE = new ValuePromise(false)
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var NULL = new ValuePromise(null)
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var UNDEFINED = new ValuePromise(undefined)
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var ZERO = new ValuePromise(0)
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var EMPTYSTRING = new ValuePromise('')
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Promise.resolve = function (value) {
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if (value instanceof Promise) return value
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if (value === null) return NULL
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if (value === undefined) return UNDEFINED
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if (value === true) return TRUE
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if (value === false) return FALSE
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if (value === 0) return ZERO
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if (value === '') return EMPTYSTRING
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if (typeof value === 'object' || typeof value === 'function') {
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try {
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var then = value.then
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if (typeof then === 'function') {
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return new Promise(then.bind(value))
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}
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} catch (ex) {
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return new Promise(function (resolve, reject) {
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reject(ex)
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})
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}
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}
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return new ValuePromise(value)
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}
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Promise.from = Promise.cast = function (value) {
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var err = new Error('Promise.from and Promise.cast are deprecated, use Promise.resolve instead')
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err.name = 'Warning'
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console.warn(err.stack)
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return Promise.resolve(value)
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}
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Promise.denodeify = function (fn, argumentCount) {
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argumentCount = argumentCount || Infinity
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return function () {
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var self = this
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var args = Array.prototype.slice.call(arguments)
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return new Promise(function (resolve, reject) {
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while (args.length && args.length > argumentCount) {
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args.pop()
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}
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args.push(function (err, res) {
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if (err) reject(err)
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else resolve(res)
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})
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fn.apply(self, args)
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})
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}
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}
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Promise.nodeify = function (fn) {
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return function () {
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var args = Array.prototype.slice.call(arguments)
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var callback = typeof args[args.length - 1] === 'function' ? args.pop() : null
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try {
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return fn.apply(this, arguments).nodeify(callback)
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} catch (ex) {
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if (callback === null || typeof callback == 'undefined') {
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return new Promise(function (resolve, reject) { reject(ex) })
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} else {
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asap(function () {
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callback(ex)
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})
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}
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}
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}
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}
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Promise.all = function () {
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var calledWithArray = arguments.length === 1 && Array.isArray(arguments[0])
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var args = Array.prototype.slice.call(calledWithArray ? arguments[0] : arguments)
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if (!calledWithArray) {
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var err = new Error('Promise.all should be called with a single array, calling it with multiple arguments is deprecated')
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err.name = 'Warning'
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console.warn(err.stack)
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}
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return new Promise(function (resolve, reject) {
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if (args.length === 0) return resolve([])
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var remaining = args.length
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function res(i, val) {
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try {
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if (val && (typeof val === 'object' || typeof val === 'function')) {
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var then = val.then
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if (typeof then === 'function') {
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then.call(val, function (val) { res(i, val) }, reject)
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return
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}
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}
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args[i] = val
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if (--remaining === 0) {
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resolve(args);
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}
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} catch (ex) {
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reject(ex)
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}
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}
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for (var i = 0; i < args.length; i++) {
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res(i, args[i])
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}
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})
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}
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Promise.reject = function (value) {
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return new Promise(function (resolve, reject) {
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reject(value);
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});
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}
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Promise.race = function (values) {
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return new Promise(function (resolve, reject) {
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values.forEach(function(value){
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Promise.resolve(value).then(resolve, reject);
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})
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});
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}
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/* Prototype Methods */
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Promise.prototype.done = function (onFulfilled, onRejected) {
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var self = arguments.length ? this.then.apply(this, arguments) : this
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self.then(null, function (err) {
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asap(function () {
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throw err
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})
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})
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}
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Promise.prototype.nodeify = function (callback) {
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if (typeof callback != 'function') return this
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this.then(function (value) {
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asap(function () {
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callback(null, value)
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})
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}, function (err) {
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asap(function () {
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callback(err)
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})
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})
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}
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Promise.prototype['catch'] = function (onRejected) {
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return this.then(null, onRejected);
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}
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