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- 'use strict';
- var PENDING = 'pending';
- var SETTLED = 'settled';
- var FULFILLED = 'fulfilled';
- var REJECTED = 'rejected';
- var NOOP = function () {};
- var isNode = typeof global !== 'undefined' && typeof global.process !== 'undefined' && typeof global.process.emit === 'function';
- var asyncSetTimer = typeof setImmediate === 'undefined' ? setTimeout : setImmediate;
- var asyncQueue = [];
- var asyncTimer;
- function asyncFlush() {
-
- for (var i = 0; i < asyncQueue.length; i++) {
- asyncQueue[i][0](asyncQueue[i][1]);
- }
-
- asyncQueue = [];
- asyncTimer = false;
- }
- function asyncCall(callback, arg) {
- asyncQueue.push([callback, arg]);
- if (!asyncTimer) {
- asyncTimer = true;
- asyncSetTimer(asyncFlush, 0);
- }
- }
- function invokeResolver(resolver, promise) {
- function resolvePromise(value) {
- resolve(promise, value);
- }
- function rejectPromise(reason) {
- reject(promise, reason);
- }
- try {
- resolver(resolvePromise, rejectPromise);
- } catch (e) {
- rejectPromise(e);
- }
- }
- function invokeCallback(subscriber) {
- var owner = subscriber.owner;
- var settled = owner._state;
- var value = owner._data;
- var callback = subscriber[settled];
- var promise = subscriber.then;
- if (typeof callback === 'function') {
- settled = FULFILLED;
- try {
- value = callback(value);
- } catch (e) {
- reject(promise, e);
- }
- }
- if (!handleThenable(promise, value)) {
- if (settled === FULFILLED) {
- resolve(promise, value);
- }
- if (settled === REJECTED) {
- reject(promise, value);
- }
- }
- }
- function handleThenable(promise, value) {
- var resolved;
- try {
- if (promise === value) {
- throw new TypeError('A promises callback cannot return that same promise.');
- }
- if (value && (typeof value === 'function' || typeof value === 'object')) {
-
- var then = value.then;
- if (typeof then === 'function') {
- then.call(value, function (val) {
- if (!resolved) {
- resolved = true;
- if (value === val) {
- fulfill(promise, val);
- } else {
- resolve(promise, val);
- }
- }
- }, function (reason) {
- if (!resolved) {
- resolved = true;
- reject(promise, reason);
- }
- });
- return true;
- }
- }
- } catch (e) {
- if (!resolved) {
- reject(promise, e);
- }
- return true;
- }
- return false;
- }
- function resolve(promise, value) {
- if (promise === value || !handleThenable(promise, value)) {
- fulfill(promise, value);
- }
- }
- function fulfill(promise, value) {
- if (promise._state === PENDING) {
- promise._state = SETTLED;
- promise._data = value;
- asyncCall(publishFulfillment, promise);
- }
- }
- function reject(promise, reason) {
- if (promise._state === PENDING) {
- promise._state = SETTLED;
- promise._data = reason;
- asyncCall(publishRejection, promise);
- }
- }
- function publish(promise) {
- promise._then = promise._then.forEach(invokeCallback);
- }
- function publishFulfillment(promise) {
- promise._state = FULFILLED;
- publish(promise);
- }
- function publishRejection(promise) {
- promise._state = REJECTED;
- publish(promise);
- if (!promise._handled && isNode) {
- global.process.emit('unhandledRejection', promise._data, promise);
- }
- }
- function notifyRejectionHandled(promise) {
- global.process.emit('rejectionHandled', promise);
- }
- function Promise(resolver) {
- if (typeof resolver !== 'function') {
- throw new TypeError('Promise resolver ' + resolver + ' is not a function');
- }
- if (this instanceof Promise === false) {
- throw new TypeError('Failed to construct \'Promise\': Please use the \'new\' operator, this object constructor cannot be called as a function.');
- }
- this._then = [];
- invokeResolver(resolver, this);
- }
- Promise.prototype = {
- constructor: Promise,
- _state: PENDING,
- _then: null,
- _data: undefined,
- _handled: false,
- then: function (onFulfillment, onRejection) {
- var subscriber = {
- owner: this,
- then: new this.constructor(NOOP),
- fulfilled: onFulfillment,
- rejected: onRejection
- };
- if ((onRejection || onFulfillment) && !this._handled) {
- this._handled = true;
- if (this._state === REJECTED && isNode) {
- asyncCall(notifyRejectionHandled, this);
- }
- }
- if (this._state === FULFILLED || this._state === REJECTED) {
-
- asyncCall(invokeCallback, subscriber);
- } else {
-
- this._then.push(subscriber);
- }
- return subscriber.then;
- },
- catch: function (onRejection) {
- return this.then(null, onRejection);
- }
- };
- Promise.all = function (promises) {
- if (!Array.isArray(promises)) {
- throw new TypeError('You must pass an array to Promise.all().');
- }
- return new Promise(function (resolve, reject) {
- var results = [];
- var remaining = 0;
- function resolver(index) {
- remaining++;
- return function (value) {
- results[index] = value;
- if (!--remaining) {
- resolve(results);
- }
- };
- }
- for (var i = 0, promise; i < promises.length; i++) {
- promise = promises[i];
- if (promise && typeof promise.then === 'function') {
- promise.then(resolver(i), reject);
- } else {
- results[i] = promise;
- }
- }
- if (!remaining) {
- resolve(results);
- }
- });
- };
- Promise.race = function (promises) {
- if (!Array.isArray(promises)) {
- throw new TypeError('You must pass an array to Promise.race().');
- }
- return new Promise(function (resolve, reject) {
- for (var i = 0, promise; i < promises.length; i++) {
- promise = promises[i];
- if (promise && typeof promise.then === 'function') {
- promise.then(resolve, reject);
- } else {
- resolve(promise);
- }
- }
- });
- };
- Promise.resolve = function (value) {
- if (value && typeof value === 'object' && value.constructor === Promise) {
- return value;
- }
- return new Promise(function (resolve) {
- resolve(value);
- });
- };
- Promise.reject = function (reason) {
- return new Promise(function (resolve, reject) {
- reject(reason);
- });
- };
- module.exports = Promise;
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