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stacktrace-js

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Framework-agnostic, micro-library for getting stack traces in all environments

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(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.StackTrace = f()}})(function(){var define,module,exports;return (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){ (function(root, factory) { 'use strict'; // Universal Module Definition (UMD) to support AMD, CommonJS/Node.js, Rhino, and browsers. /* istanbul ignore next */ if (typeof define === 'function' && define.amd) { define('error-stack-parser', ['stackframe'], factory); } else if (typeof exports === 'object') { module.exports = factory(require('stackframe')); } else { root.ErrorStackParser = factory(root.StackFrame); } }(this, function ErrorStackParser(StackFrame) { 'use strict'; var FIREFOX_SAFARI_STACK_REGEXP = /(^|@)\S+:\d+/; var CHROME_IE_STACK_REGEXP = /^\s*at .*(\S+:\d+|\(native\))/m; var SAFARI_NATIVE_CODE_REGEXP = /^(eval@)?(\[native code])?$/; return { /** * Given an Error object, extract the most information from it. * * @param {Error} error object * @return {Array} of StackFrames */ parse: function ErrorStackParser$$parse(error) { if (typeof error.stacktrace !== 'undefined' || typeof error['opera#sourceloc'] !== 'undefined') { return this.parseOpera(error); } else if (error.stack && error.stack.match(CHROME_IE_STACK_REGEXP)) { return this.parseV8OrIE(error); } else if (error.stack) { return this.parseFFOrSafari(error); } else { throw new Error('Cannot parse given Error object'); } }, // Separate line and column numbers from a string of the form: (URI:Line:Column) extractLocation: function ErrorStackParser$$extractLocation(urlLike) { // Fail-fast but return locations like "(native)" if (urlLike.indexOf(':') === -1) { return [urlLike]; } var regExp = /(.+?)(?::(\d+))?(?::(\d+))?$/; var parts = regExp.exec(urlLike.replace(/[()]/g, '')); return [parts[1], parts[2] || undefined, parts[3] || undefined]; }, parseV8OrIE: function ErrorStackParser$$parseV8OrIE(error) { var filtered = error.stack.split('\n').filter(function(line) { return !!line.match(CHROME_IE_STACK_REGEXP); }, this); return filtered.map(function(line) { if (line.indexOf('(eval ') > -1) { // Throw away eval information until we implement stacktrace.js/stackframe#8 line = line.replace(/eval code/g, 'eval').replace(/(\(eval at [^()]*)|(\),.*$)/g, ''); } var sanitizedLine = line.replace(/^\s+/, '').replace(/\(eval code/g, '('); // capture and preseve the parenthesized location "(/foo/my bar.js:12:87)" in // case it has spaces in it, as the string is split on \s+ later on var location = sanitizedLine.match(/ (\((.+):(\d+):(\d+)\)$)/); // remove the parenthesized location from the line, if it was matched sanitizedLine = location ? sanitizedLine.replace(location[0], '') : sanitizedLine; var tokens = sanitizedLine.split(/\s+/).slice(1); // if a location was matched, pass it to extractLocation() otherwise pop the last token var locationParts = this.extractLocation(location ? location[1] : tokens.pop()); var functionName = tokens.join(' ') || undefined; var fileName = ['eval', '<anonymous>'].indexOf(locationParts[0]) > -1 ? undefined : locationParts[0]; return new StackFrame({ functionName: functionName, fileName: fileName, lineNumber: locationParts[1], columnNumber: locationParts[2], source: line }); }, this); }, parseFFOrSafari: function ErrorStackParser$$parseFFOrSafari(error) { var filtered = error.stack.split('\n').filter(function(line) { return !line.match(SAFARI_NATIVE_CODE_REGEXP); }, this); return filtered.map(function(line) { // Throw away eval information until we implement stacktrace.js/stackframe#8 if (line.indexOf(' > eval') > -1) { line = line.replace(/ line (\d+)(?: > eval line \d+)* > eval:\d+:\d+/g, ':$1'); } if (line.indexOf('@') === -1 && line.indexOf(':') === -1) { // Safari eval frames only have function names and nothing else return new StackFrame({ functionName: line }); } else { var functionNameRegex = /((.*".+"[^@]*)?[^@]*)(?:@)/; var matches = line.match(functionNameRegex); var functionName = matches && matches[1] ? matches[1] : undefined; var locationParts = this.extractLocation(line.replace(functionNameRegex, '')); return new StackFrame({ functionName: functionName, fileName: locationParts[0], lineNumber: locationParts[1], columnNumber: locationParts[2], source: line }); } }, this); }, parseOpera: function ErrorStackParser$$parseOpera(e) { if (!e.stacktrace || (e.message.indexOf('\n') > -1 && e.message.split('\n').length > e.stacktrace.split('\n').length)) { return this.parseOpera9(e); } else if (!e.stack) { return this.parseOpera10(e); } else { return this.parseOpera11(e); } }, parseOpera9: function ErrorStackParser$$parseOpera9(e) { var lineRE = /Line (\d+).*script (?:in )?(\S+)/i; var lines = e.message.split('\n'); var result = []; for (var i = 2, len = lines.length; i < len; i += 2) { var match = lineRE.exec(lines[i]); if (match) { result.push(new StackFrame({ fileName: match[2], lineNumber: match[1], source: lines[i] })); } } return result; }, parseOpera10: function ErrorStackParser$$parseOpera10(e) { var lineRE = /Line (\d+).*script (?:in )?(\S+)(?:: In function (\S+))?$/i; var lines = e.stacktrace.split('\n'); var result = []; for (var i = 0, len = lines.length; i < len; i += 2) { var match = lineRE.exec(lines[i]); if (match) { result.push( new StackFrame({ functionName: match[3] || undefined, fileName: match[2], lineNumber: match[1], source: lines[i] }) ); } } return result; }, // Opera 10.65+ Error.stack very similar to FF/Safari parseOpera11: function ErrorStackParser$$parseOpera11(error) { var filtered = error.stack.split('\n').filter(function(line) { return !!line.match(FIREFOX_SAFARI_STACK_REGEXP) && !line.match(/^Error created at/); }, this); return filtered.map(function(line) { var tokens = line.split('@'); var locationParts = this.extractLocation(tokens.pop()); var functionCall = (tokens.shift() || ''); var functionName = functionCall .replace(/<anonymous function(: (\w+))?>/, '$2') .replace(/\([^)]*\)/g, '') || undefined; var argsRaw; if (functionCall.match(/\(([^)]*)\)/)) { argsRaw = functionCall.replace(/^[^(]+\(([^)]*)\)$/, '$1'); } var args = (argsRaw === undefined || argsRaw === '[arguments not available]') ? undefined : argsRaw.split(','); return new StackFrame({ functionName: functionName, args: args, fileName: locationParts[0], lineNumber: locationParts[1], columnNumber: locationParts[2], source: line }); }, this); } }; })); },{"stackframe":2}],2:[function(require,module,exports){ (function(root, factory) { 'use strict'; // Universal Module Definition (UMD) to support AMD, CommonJS/Node.js, Rhino, and browsers. /* istanbul ignore next */ if (typeof define === 'function' && define.amd) { define('stackframe', [], factory); } else if (typeof exports === 'object') { module.exports = factory(); } else { root.StackFrame = factory(); } }(this, function() { 'use strict'; function _isNumber(n) { return !isNaN(parseFloat(n)) && isFinite(n); } function _capitalize(str) { return str.charAt(0).toUpperCase() + str.substring(1); } function _getter(p) { return function() { return this[p]; }; } var booleanProps = ['isConstructor', 'isEval', 'isNative', 'isToplevel']; var numericProps = ['columnNumber', 'lineNumber']; var stringProps = ['fileName', 'functionName', 'source']; var arrayProps = ['args']; var props = booleanProps.concat(numericProps, stringProps, arrayProps); function StackFrame(obj) { if (!obj) return; for (var i = 0; i < props.length; i++) { if (obj[props[i]] !== undefined) { this['set' + _capitalize(props[i])](obj[props[i]]); } } } StackFrame.prototype = { getArgs: function() { return this.args; }, setArgs: function(v) { if (Object.prototype.toString.call(v) !== '[object Array]') { throw new TypeError('Args must be an Array'); } this.args = v; }, getEvalOrigin: function() { return this.evalOrigin; }, setEvalOrigin: function(v) { if (v instanceof StackFrame) { this.evalOrigin = v; } else if (v instanceof Object) { this.evalOrigin = new StackFrame(v); } else { throw new TypeError('Eval Origin must be an Object or StackFrame'); } }, toString: function() { var fileName = this.getFileName() || ''; var lineNumber = this.getLineNumber() || ''; var columnNumber = this.getColumnNumber() || ''; var functionName = this.getFunctionName() || ''; if (this.getIsEval()) { if (fileName) { return '[eval] (' + fileName + ':' + lineNumber + ':' + columnNumber + ')'; } return '[eval]:' + lineNumber + ':' + columnNumber; } if (functionName) { return functionName + ' (' + fileName + ':' + lineNumber + ':' + columnNumber + ')'; } return fileName + ':' + lineNumber + ':' + columnNumber; } }; StackFrame.fromString = function StackFrame$$fromString(str) { var argsStartIndex = str.indexOf('('); var argsEndIndex = str.lastIndexOf(')'); var functionName = str.substring(0, argsStartIndex); var args = str.substring(argsStartIndex + 1, argsEndIndex).split(','); var locationString = str.substring(argsEndIndex + 1); if (locationString.indexOf('@') === 0) { var parts = /@(.+?)(?::(\d+))?(?::(\d+))?$/.exec(locationString, ''); var fileName = parts[1]; var lineNumber = parts[2]; var columnNumber = parts[3]; } return new StackFrame({ functionName: functionName, args: args || undefined, fileName: fileName, lineNumber: lineNumber || undefined, columnNumber: columnNumber || undefined }); }; for (var i = 0; i < booleanProps.length; i++) { StackFrame.prototype['get' + _capitalize(booleanProps[i])] = _getter(booleanProps[i]); StackFrame.prototype['set' + _capitalize(booleanProps[i])] = (function(p) { return function(v) { this[p] = Boolean(v); }; })(booleanProps[i]); } for (var j = 0; j < numericProps.length; j++) { StackFrame.prototype['get' + _capitalize(numericProps[j])] = _getter(numericProps[j]); StackFrame.prototype['set' + _capitalize(numericProps[j])] = (function(p) { return function(v) { if (!_isNumber(v)) { throw new TypeError(p + ' must be a Number'); } this[p] = Number(v); }; })(numericProps[j]); } for (var k = 0; k < stringProps.length; k++) { StackFrame.prototype['get' + _capitalize(stringProps[k])] = _getter(stringProps[k]); StackFrame.prototype['set' + _capitalize(stringProps[k])] = (function(p) { return function(v) { this[p] = String(v); }; })(stringProps[k]); } return StackFrame; })); },{}],3:[function(require,module,exports){ (function (process,global){ /*! * @overview es6-promise - a tiny implementation of Promises/A+. * @copyright Copyright (c) 2014 Yehuda Katz, Tom Dale, Stefan Penner and contributors (Conversion to ES6 API by Jake Archibald) * @license Licensed under MIT license * See https://raw.githubusercontent.com/stefanpenner/es6-promise/master/LICENSE * @version 3.3.1 */ (function (global, factory) { typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() : typeof define === 'function' && define.amd ? define(factory) : (global.ES6Promise = factory()); }(this, (function () { 'use strict'; function objectOrFunction(x) { return typeof x === 'function' || typeof x === 'object' && x !== null; } function isFunction(x) { return typeof x === 'function'; } var _isArray = undefined; if (!Array.isArray) { _isArray = function (x) { return Object.prototype.toString.call(x) === '[object Array]'; }; } else { _isArray = Array.isArray; } var isArray = _isArray; var len = 0; var vertxNext = undefined; var customSchedulerFn = undefined; var asap = function asap(callback, arg) { queue[len] = callback; queue[len + 1] = arg; len += 2; if (len === 2) { // If len is 2, that means that we need to schedule an async flush. // If additional callbacks are queued before the queue is flushed, they // will be processed by this flush that we are scheduling. if (customSchedulerFn) { customSchedulerFn(flush); } else { scheduleFlush(); } } }; function setScheduler(scheduleFn) { customSchedulerFn = scheduleFn; } function setAsap(asapFn) { asap = asapFn; } var browserWindow = typeof window !== 'undefined' ? window : undefined; var browserGlobal = browserWindow || {}; var BrowserMutationObserver = browserGlobal.MutationObserver || browserGlobal.WebKitMutationObserver; var isNode = typeof self === 'undefined' && typeof process !== 'undefined' && ({}).toString.call(process) === '[object process]'; // test for web worker but not in IE10 var isWorker = typeof Uint8ClampedArray !== 'undefined' && typeof importScripts !== 'undefined' && typeof MessageChannel !== 'undefined'; // node function useNextTick() { // node version 0.10.x displays a deprecation warning when nextTick is used recursively // see https://github.com/cujojs/when/issues/410 for details return function () { return process.nextTick(flush); }; } // vertx function useVertxTimer() { return function () { vertxNext(flush); }; } function useMutationObserver() { var iterations = 0; var observer = new BrowserMutationObserver(flush); var node = document.createTextNode(''); observer.observe(node, { characterData: true }); return function () { node.data = iterations = ++iterations % 2; }; } // web worker function useMessageChannel() { var channel = new MessageChannel(); channel.port1.onmessage = flush; return function () { return channel.port2.postMessage(0); }; } function useSetTimeout() { // Store setTimeout reference so es6-promise will be unaffected by // other code modifying setTimeout (like sinon.useFakeTimers()) var globalSetTimeout = setTimeout; return function () { return globalSetTimeout(flush, 1); }; } var queue = new Array(1000); function flush() { for (var i = 0; i < len; i += 2) { var callback = queue[i]; var arg = queue[i + 1]; callback(arg); queue[i] = undefined; queue[i + 1] = undefined; } len = 0; } function attemptVertx() { try { var r = require; var vertx = r('vertx'); vertxNext = vertx.runOnLoop || vertx.runOnContext; return useVertxTimer(); } catch (e) { return useSetTimeout(); } } var scheduleFlush = undefined; // Decide what async method to use to triggering processing of queued callbacks: if (isNode) { scheduleFlush = useNextTick(); } else if (BrowserMutationObserver) { scheduleFlush = useMutationObserver(); } else if (isWorker) { scheduleFlush = useMessageChannel(); } else if (browserWindow === undefined && typeof require === 'function') { scheduleFlush = attemptVertx(); } else { scheduleFlush = useSetTimeout(); } function then(onFulfillment, onRejection) { var _arguments = arguments; var parent = this; var child = new this.constructor(noop); if (child[PROMISE_ID] === undefined) { makePromise(child); } var _state = parent._state; if (_state) { (function () { var callback = _arguments[_state - 1]; asap(function () { return invokeCallback(_state, child, callback, parent._result); }); })(); } else { subscribe(parent, child, onFulfillment, onRejection); } return child; } /** `Promise.resolve` returns a promise that will become resolved with the passed `value`. It is shorthand for the following: ```javascript let promise = new Promise(function(resolve, reject){ resolve(1); }); promise.then(function(value){ // value === 1 }); ``` Instead of writing the above, your code now simply becomes the following: ```javascript let promise = Promise.resolve(1); promise.then(function(value){ // value === 1 }); ``` @method resolve @static @param {Any} value value that the returned promise will be resolved with Useful for tooling. @return {Promise} a promise that will become fulfilled with the given `value` */ function resolve(object) { /*jshint validthis:true */ var Constructor = this; if (object && typeof object === 'object' && object.constructor === Constructor) { return object; } var promise = new Constructor(noop); _resolve(promise, object); return promise; } var PROMISE_ID = Math.random().toString(36).substring(16); function noop() {} var PENDING = void 0; var FULFILLED = 1; var REJECTED = 2; var GET_THEN_ERROR = new ErrorObject(); function selfFulfillment() { return new TypeError("You cannot resolve a promise with itself"); } function cannotReturnOwn() { return new TypeError('A promises callback cannot return that same promise.'); } function getThen(promise) { try { return promise.then; } catch (error) { GET_THEN_ERROR.error = error; return GET_THEN_ERROR; } } function tryThen(then, value, fulfillmentHandler, rejectionHandler) { try { then.call(value, fulfillmentHandler, rejectionHandler); } catch (e) { return e; } } function handleForeignThenable(promise, thenable, then) { asap(function (promise) { var sealed = false; var error = tryThen(then, thenable, function (value) { if (sealed) { return; } sealed = true; if (thenable !== value) { _resolve(promise, value); } else { fulfill(promise, value); } }, function (reason) { if (sealed) { return; } sealed = true; _reject(promise, reason); }, 'Settle: ' + (promise._label || ' unknown promise')); if (!sealed && error) { sealed = true; _reject(promise, error); } }, promise); } function handleOwnThenable(promise, thenable) { if (thenable._state === FULFILLED) { fulfill(promise, thenable._result); } else if (thenable._state === REJECTED) { _reject(promise, thenable._result); } else { subscribe(thenable, undefined, function (value) { return _resolve(promise, value); }, function (reason) { return _reject(promise, reason); }); } } function handleMaybeThenable(promise, maybeThenable, then$$) { if (maybeThenable.constructor === promise.constructor && then$$ === then && maybeThenable.constructor.resolve === resolve) { handleOwnThenable(promise, maybeThenable); } else { if (then$$ === GET_THEN_ERROR) { _reject(promise, GET_THEN_ERROR.error); } else if (then$$ === undefined) { fulfill(promise, maybeThenable); } else if (isFunction(then$$)) { handleForeignThenable(promise, maybeThenable, then$$); } else { fulfill(promise, maybeThenable); } } } function _resolve(promise, value) { if (promise === value) { _reject(promise, selfFulfillment()); } else if (objectOrFunction(value)) { handleMaybeThenable(promise, value, getThen(value)); } else { fulfill(promise, value); } } function publishRejection(promise) { if (promise._onerror) { promise._onerror(promise._result); } publish(promise); } function fulfill(promise, value) { if (promise._state !== PENDING) { return; } promise._result = value; promise._state = FULFILLED; if (promise._subscribers.length !== 0) { asap(publish, promise); } } function _reject(promise, reason) { if (promise._state !== PENDING) { return; } promise._state = REJECTED; promise._result = reason; asap(publishRejection, promise); } function subscribe(parent, child, onFulfillment, onRejection) { var _subscribers = parent._subscribers; var length = _subscribers.length; parent._onerror = null; _subscribers[length] = child; _subscribers[length + FULFILLED] = onFulfillment; _subscribers[length + REJECTED] = onRejection; if (length === 0 && parent._state) { asap(publish, parent); } } function publish(promise) { var subscribers = promise._subscribers; var settled = promise._state; if (subscribers.length === 0) { return; } var child = undefined, callback = undefined, detail = promise._result; for (var i = 0; i < subscribers.length; i += 3) { child = subscribers[i]; callback = subscribers[i + settled]; if (child) { invokeCallback(settled, child, callback, detail); } else { callback(detail); } } promise._subscribers.length = 0; } function ErrorObject() { this.error = null; } var TRY_CATCH_ERROR = new ErrorObject(); function tryCatch(callback, detail) { try { return callback(detail); } catch (e) { TRY_CATCH_ERROR.error = e; return TRY_CATCH_ERROR; } } function invokeCallback(settled, promise, callback, detail) { var hasCallback = isFunction(callback), value = undefined, error = undefined, succeeded = undefined, failed = undefined; if (hasCallback) { value = tryCatch(callback, detail); if (value === TRY_CATCH_ERROR) { failed = true; error = value.error; value = null; } else { succeeded = true; } if (promise === value) { _reject(promise, cannotReturnOwn()); return; } } else { value = detail; succeeded = true; } if (promise._state !== PENDING) { // noop } else if (hasCallback && succeeded) { _resolve(promise, value); } else if (failed) { _reject(promise, error); } else if (settled === FULFILLED) { fulfill(promise, value); } else if (settled === REJECTED) { _reject(promise, value); } } function initializePromise(promise, resolver) { try { resolver(function resolvePromise(value) { _resolve(promise, value); }, function rejectPromise(reason) { _reject(promise, reason); }); } catch (e) { _reject(promise, e); } } var id = 0; function nextId() { return id++; } function makePromise(promise) { promise[PROMISE_ID] = id++; promise._state = undefined; promise._result = undefined; promise._subscribers = []; } function Enumerator(Constructor, input) { this._instanceConstructor = Constructor; this.promise = new Constructor(noop); if (!this.promise[PROMISE_ID]) { makePromise(this.promise); } if (isArray(input)) { this._input = input; this.length = input.length; this._remaining = input.length; this._result = new Array(this.length); if (this.length === 0) { fulfill(this.promise, this._result); } else { this.length = this.length || 0; this._enumerate(); if (this._remaining === 0) { fulfill(this.promise, this._result); } } } else { _reject(this.promise, validationError()); } } function validationError() { return new Error('Array Methods must be provided an Array'); }; Enumerator.prototype._enumerate = function () { var length = this.length; var _input = this._input; for (var i = 0; this._state === PENDING && i < length; i++) { this._eachEntry(_input[i], i); } }; Enumerator.prototype._eachEntry = function (entry, i) { var c = this._instanceConstructor; var resolve$$ = c.resolve; if (resolve$$ === resolve) { var _then = getThen(entry); if (_then === then && entry._state !== PENDING) { this._settledAt(entry._state, i, entry._result); } else if (typeof _then !== 'function') { this._remaining--; this._result[i] = entry; } else if (c === Promise) { var promise = new c(noop); handleMaybeThenable(promise, entry, _then); this._willSettleAt(promise, i); } else { this._willSettleAt(new c(function (resolve$$) { return resolve$$(entry); }), i); } } else { this._willSettleAt(resolve$$(entry), i); } }; Enumerator.prototype._settledAt = function (state, i, value) { var promise = this.promise; if (promise._state === PENDING) { this._remaining--; if (state === REJECTED) { _reject(promise, value); } else { this._result[i] = value; } } if (this._remaining === 0) { fulfill(promise, this._result); } }; Enumerator.prototype._willSettleAt = function (promise, i) { var enumerator = this; subscribe(promise, undefined, function (value) { return enumerator._settledAt(FULFILLED, i, value); }, function (reason) { return enumerator._settledAt(REJECTED, i, reason); }); }; /** `Promise.all` accepts an array of promises, and returns a new promise which is fulfilled with an array of fulfillment values for the passed promises, or rejected with the reason of the first passed promise to be rejected. It casts all elements of the passed iterable to promises as it runs this algorithm. Example: ```javascript let promise1 = resolve(1); let promise2 = resolve(2); let promise3 = resolve(3); let promises = [ promise1, promise2, promise3 ]; Promise.all(promises).then(function(array){ // The array here would be [ 1, 2, 3 ]; }); ``` If any of the `promises` given to `all` are rejected, the first promise that is rejected will be given as an argument to the returned promises's rejection handler. For example: Example: ```javascript let promise1 = resolve(1); let promise2 = reject(new Error("2")); let promise3 = reject(new Error("3")); let promises = [ promise1, promise2, promise3 ]; Promise.all(promises).then(function(array){ // Code here never runs because there are rejected promises! }, function(error) { // error.message === "2" }); ``` @method all @static @param {Array} entries array of promises @param {String} label optional string for labeling the promise. Useful for tooling. @return {Promise} promise that is fulfilled when all `promises` have been fulfilled, or rejected if any of them become rejected. @static */ function all(entries) { return new Enumerator(this, entries).promise; } /** `Promise.race` returns a new promise which is settled in the same way as the first passed promise to settle. Example: ```javascript let promise1 = new Promise(function(resolve, reject){ setTimeout(function(){ resolve('promise 1'); }, 200); }); let promise2 = new Promise(function(resolve, reject){ setTimeout(function(){ resolve('promise 2'); }, 100); }); Promise.race([promise1, promise2]).then(function(result){ // result === 'promise 2' because it was resolved before promise1 // was resolved. }); ``` `Promise.race` is deterministic in that only the state of the first settled promise matters. For example, even if other promises given to the `promises` array argument are resolved, but the first settled promise has become rejected before the other promises became fulfilled, the returned promise will become rejected: ```javascript let promise1 = new Promise(function(resolve, reject){ setTimeout(function(){ resolve('promise 1'); }, 200); }); let promise2 = new Promise(function(resolve, reject){ setTimeout(function(){ reject(new Error('promise 2')); }, 100); }); Promise.race([promise1, promise2]).then(function(result){ // Code here never runs }, function(reason){ // reason.message === 'promise 2' because promise 2 became rejected before // promise 1 became fulfilled }); ``` An example real-world use case is implementing timeouts: ```javascript Promise.race([ajax('foo.json'), timeout(5000)]) ``` @method race @static @param {Array} promises array of promises to observe Useful for tooling. @return {Promise} a promise which settles in the same way as the first passed promise to settle. */ function race(entries) { /*jshint validthis:true */ var Constructor = this; if (!isArray(entries)) { return new Constructor(function (_, reject) { return reject(new TypeError('You must pass an array to race.')); }); } else { return new Constructor(function (resolve, reject) { var length = entries.length; for (var i = 0; i < length; i++) { Constructor.resolve(entries[i]).then(resolve, reject); } }); } } /** `Promise.reject` returns a promise rejected with the passed `reason`. It is shorthand for the following: ```javascript let promise = new Promise(function(resolve, reject){ reject(new Error('WHOOPS')); }); promise.then(function(value){ // Code here doesn't run because the promise is rejected! }, function(reason){ // reason.message === 'WHOOPS' }); ``` Instead of writing the above, your code now simply becomes the following: ```javascript let promise = Promise.reject(new Error('WHOOPS')); promise.then(function(value){ // Code here doesn't run because the promise is rejected! }, function(reason){ // reason.message === 'WHOOPS' }); ``` @method reject @static @param {Any} reason value that the returned promise will be rejected with. Useful for tooling. @return {Promise} a promise rejected with the given `reason`. */ function reject(reason) { /*jshint validthis:true */ var Constructor = this; var promise = new Constructor(noop); _reject(promise, reason); return promise; } function needsResolver() { throw new TypeError('You must pass a resolver function as the first argument to the promise constructor'); } function needsNew() { throw new TypeError("Failed to construct 'Promise': Please use the 'new' operator, this object constructor cannot be called as a function."); } /** Promise objects represent the eventual result of an asynchronous operation. The primary way of interacting with a promise is through its `then` method, which registers callbacks to receive either a promise's eventual value or the reason why the promise cannot be fulfilled. Terminology ----------- - `promise` is an object or function with a `then` method whose behavior conforms to this specification. - `thenable` is an object or function that defines a `then` method. - `value` is any legal JavaScript value (including undefined, a thenable, or a promise). - `exception` is a value that is thrown using the throw statement. - `reason` is a value that indicates why a promise was rejected. - `settled` the final resting state of a promise, fulfilled or rejected. A promise can be in one of three states: pending, fulfilled, or rejected. Promises that are fulfilled have a fulfillment value and are in the fulfilled state. Promises that are rejected have a rejection reason and are in the rejected state. A fulfillment value is never a thenable. Promises can also be said to *resolve* a value. If this value is also a promise, then the original promise's settled state will match the value's settled state. So a promise that *resolves* a promise that rejects will itself reject, and a promise that *resolves* a promise that fulfills will itself fulfill. Basic Usage: ------------ ```js let promise = new Promise(function(resolve, reject) { // on success resolve(value); // on failure reject(reason); }); promise.then(function(value) { // on fulfillment }, function(reason) { // on rejection }); ``` Advanced Usage: --------------- Promises shine when abstracting away asynchronous interactions such as `XMLHttpRequest`s. ```js function getJSON(url) { return new Promise(function(resolve, reject){ let xhr = new XMLHttpRequest(); xhr.open('GET', url); xhr.onreadystatechange = handler; xhr.responseType = 'json'; xhr.setRequestHeader('Accept', 'application/json'); xhr.send(); function handler() { if (this.readyState === this.DONE) { if (this.status === 200) { resolve(this.response); } else { reject(new Error('getJSON: `' + url + '` failed with status: [' + this.status + ']')); } } }; }); } getJSON('/posts.json').then(function(json) { // on fulfillment }, function(reason) { // on rejection }); ``` Unlike callbacks, promises are great composable primitives. ```js Promise.all([ getJSON('/posts'), getJSON('/comments') ]).then(function(values){ values[0] // => postsJSON values[1] // => commentsJSON return values; }); ``` @class Promise @param {function} resolver Useful for tooling. @constructor */ function Promise(resolver) { this[PROMISE_ID] = nextId(); this._result = this._state = undefined; this._subscribers = []; if (noop !== resolver) { typeof resolver !== 'function' && needsResolver(); this instanceof Promise ? initializePromise(this, resolver) : needsNew(); } } Promise.all = all; Promise.race = race; Promise.resolve = resolve; Promise.reject = reject; Promise._setScheduler = setScheduler; Promise._setAsap = setAsap; Promise._asap = asap; Promise.prototype = { constructor: Promise, /** The primary way of interacting with a promise is through its `then` method, which registers callbacks to receive either a promise's eventual value or the reason why the promise cannot be fulfilled. ```js findUser().then(function(user){ // user is available }, function(reason){ // user is unavailable, and you are given the reason why }); ``` Chaining -------- The return value of `then` is itself a promise. This second, 'downstream' promise is resolved with the return value of the first promise's fulfillment or rejection handler, or rejected if the handler throws an exception. ```js findUser().then(function (user) { return user.name; }, function (reason) { return 'default name'; }).then(function (userName) { // If `findUser` fulfilled, `userName` will be the user's name, otherwise it // will be `'default name'` }); findUser().then(function (user) { throw new Error('Found user, but still unhappy'); }, function (reason) { throw new Error('`findUser` rejected and we're unhappy'); }).then(function (value) { // never reached }, function (reason) { // if `findUser` fulfilled, `reason` will be 'Found user, but still unhappy'. // If `findUser` rejected, `reason` will be '`findUser` rejected and we're unhappy'. }); ``` If the downstream promise does not specify a rejection handler, rejection reasons will be propagated further downstream. ```js findUser().then(function (user) { throw new PedagogicalException('Upstream error'); }).then(function (value) { // never reached }).then(function (value) { // never reached }, function (reason) { // The `PedgagocialException` is propagated all the way down to here }); ``` Assimilation ------------ Sometimes the value you want to propagate to a downstream promise can only be retrieved asynchronously. This can be achieved by returning a promise in the fulfillment or rejection handler. The downstream promise will then be pending until the returned promise is settled. This is called *assimilation*. ```js findUser().then(function (user) { return findCommentsByAuthor(user); }).then(function (comments) { // The user's comments are now available }); ``` If the assimliated promise rejects, then the downstream promise will also reject. ```js findUser().then(function (user) { return findCommentsByAuthor(user); }).then(function (comments) { // If `findCommentsByAuthor` fulfills, we'll have the value here }, function (reason) { // If `findCommentsByAuthor` rejects, we'll have the reason here }); ``` Simple Example -------------- Synchronous Example ```javascript let result; try { result = findResult(); // success } catch(reason) { // failure } ``` Errback Example ```js findResult(function(result, err){ if (err) { // failure } else { // success } }); ``` Promise Example; ```javascript findResult().then(function(result){ // success }, function(reason){ // failure }); ``` Advanced Example -------------- Synchronous Example ```javascript let author, books; try { author = findAuthor(); books = findBooksByAuthor(author); // success } catch(reason) { // failure } ``` Errback Example ```js function foundBooks(books) { } function failure(reason) { } findAuthor(function(author, err){ if (err) { failure(err); // failure } else { try { findBoooksByAuthor(author, function(books, err) { if (err) { failure(err); } else { try { foundBooks(books); } catch(reason) { failure(reason); } } }); } catch(error) { failure(err); } // success } }); ``` Promise Example; ```javascript findAuthor(). then(findBooksByAuthor). then(function(books){ // found books }).catch(function(reason){ // something went wrong }); ``` @method then @param {Function} onFulfilled @param {Function} onRejected Useful for tooling. @return {Promise} */ then: then, /** `catch` is simply sugar for `then(undefined, onRejection)` which makes it the same as the catch block of a try/catch statement. ```js function findAuthor(){ throw new Error('couldn't find that author'); } // synchronous try { findAuthor(); } catch(reason) { // something went wrong } // async with promises findAuthor().catch(function(reason){ // something went wrong }); ``` @method catch @param {Function} onRejection Useful for tooling. @return {Promise} */ 'catch': function _catch(onRejection) { return this.then(null, onRejection); } }; function polyfill() { var local = undefined; if (typeof global !== 'undefined') { local = global; } else if (typeof self !== 'undefined') { local = self; } else { try { local = Function('return this')(); } catch (e) { throw new Error('polyfill failed because global object is unavailable in this environment'); } } var P = local.Promise; if (P) { var promiseToString = null; try { promiseToString = Object.prototype.toString.call(P.resolve()); } catch (e) { // silently ignored } if (promiseToString === '[object Promise]' && !P.cast) { return; } } local.Promise = Promise; } polyfill(); // Strange compat.. Promise.polyfill = polyfill; Promise.Promise = Promise; return Promise; }))); }).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {}) },{"_process":5}],4:[function(require,module,exports){ (function (global){ /*! JSON v3.3.2 | http://bestiejs.github.io/json3 | Copyright 2012-2014, Kit Cambridge | http://kit.mit-license.org */ ;(function () { // Detect the `define` function exposed by asynchronous module loaders. The // strict `define` check is necessary for compatibility with `r.js`. var isLoader = typeof define === "function" && define.amd; // A set of types used to distinguish objects from primitives. var objectTypes = { "function": true, "object": true }; // Detect the `exports` object exposed by CommonJS implementations. var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports; // Use the `global` object exposed by Node (including Browserify via // `insert-module-globals`), Narwhal, and Ringo as the default context, // and the `window` object in browsers. Rhino exports a `global` function // instead. var root = objectTypes[typeof window] && window || this, freeGlobal = freeExports && objectTypes[typeof module] && module && !module.nodeType && typeof global == "object" && global; if (freeGlobal && (freeGlobal["global"] === freeGlobal || freeGlobal["window"] === freeGlobal || freeGlobal["self"] === freeGlobal)) { root = freeGlobal; } // Public: Initializes JSON 3 using the given `context` object, attaching the // `stringify` and `parse` functions to the specified `exports` object. function runInContext(context, exports) { context || (context = root["Object"]()); exports || (exports = root["Object"]()); // Native constructor aliases. var Number = context["Number"] || root["Number"], String = context["String"] || root["String"], Object = context["Object"] || root["Object"], Date = context["Date"] || root["Date"], SyntaxError = context["SyntaxError"] || root["SyntaxError"], TypeError = context["TypeError"] || root["TypeError"], Math = context["Math"] || root["Math"], nativeJSON = context["JSON"] || root["JSON"]; // Delegate to the native `stringify` and `parse` implementations. if (typeof nativeJSON == "object" && nativeJSON) { exports.stringify = nativeJSON.stringify; exports.parse = nativeJSON.parse; } // Convenience aliases. var objectProto = Object.prototype, getClass = objectProto.toString, isProperty, forEach, undef; // Test the `Date#getUTC*` methods. Based on work by @Yaffle. var isExtended = new Date(-3509827334573292); try { // The `getUTCFullYear`, `Month`, and `Date` methods return nonsensical // results for certain dates in Opera >= 10.53. isExtended = isExtended.getUTCFullYear() == -109252 && isExtended.getUTCMonth() === 0 && isExtended.getUTCDate() === 1 && // Safari < 2.0.2 stores the internal millisecond time value correctly, // but clips the values returned by the date methods to the range of // signed 32-bit integers ([-2 ** 31, 2 ** 31 - 1]). isExtended.getUTCHours() == 10 && isExtended.getUTCMinutes() == 37 && isExtended.getUTCSeconds() == 6 && isExtended.getUTCMilliseconds() == 708; } catch (exception) {} // Internal: Determines whether the native `JSON.stringify` and `parse` // implementations are spec-compliant. Based on work by Ken Snyder. function has(name) { if (has[name] !== undef) { // Return cached feature test result. return has[name]; } var isSupported; if (name == "bug-string-char-index") { // IE <= 7 doesn't support accessing string characters using square // bracket notation. IE 8 only supports this for primitives. isSupported = "a"[0] != "a"; } else if (name == "json") { // Indicates whether both `JSON.stringify` and `JSON.parse` are // supported. isSupported = has("json-stringify") && has("json-parse"); } else { var value, serialized = '{"a":[1,true,false,null,"\\u0000\\b\\n\\f\\r\\t"]}'; // Test `JSON.stringify`. if (name == "json-stringify") { var stringify = exports.stringify, stringifySupported = typeof stringify == "function" && isExtended; if (stringifySupported) { // A test function object with a custom `toJSON` method. (value = function () { return 1; }).toJSON = value; try { stringifySupported = // Firefox 3.1b1 and b2 serialize string, number, and boolean // primitives as object literals. stringify(0) === "0" && // FF 3.1b1, b2, and JSON 2 serialize wrapped primitives as object // literals. stringify(new Number()) === "0" && stringify(new String()) == '""' && // FF 3.1b1, 2 throw an error if the value is `null`, `undefined`, or // does not define a canonical JSON representation (this applies to // objects with `toJSON` properties as well, *unless* they are nested // within an object or array). stringify(getClass) === undef && // IE 8 serializes `undefined` as `"undefined"`. Safari <= 5.1.7 and // FF 3.1b3 pass this test. stringify(undef) === undef && // Safari <= 5.1.7 and FF 3.1b3 throw `Error`s and `TypeError`s, // respectively, if the value is omitted entirely. stringify() === undef && // FF 3.1b1, 2 throw an error if the given value is not a number, // string, array, object, Boolean, or `null` literal. This applies to // objects with custom `toJSON` methods as well, unless they are nested // inside object or array literals. YUI 3.0.0b1 ignores custom `toJSON` // methods entirely. stringify(value) === "1" && stringify([value]) == "[1]" && // Prototype <= 1.6.1 serializes `[undefined]` as `"[]"` instead of // `"[null]"`. stringify([undef]) == "[null]" && // YUI 3.0.0b1 fails to serialize `null` literals. stringify(null) == "null" && // FF 3.1b1, 2 halts serialization if an array contains a function: // `[1, true, getClass, 1]` serializes as "[1,true,],". FF 3.1b3 // elides non-JSON values from objects and arrays, unless they // define custom `toJSON` methods. stringify([undef, getClass, null]) == "[null,null,null]" && // Simple serialization test. FF 3.1b1 uses Unicode escape sequences // where character escape codes are expected (e.g., `\