How to use promise method in Puppeteer

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es6-promise.js

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1/*!2 * @overview es6-promise - a tiny implementation of Promises/A+.3 * @copyright Copyright (c) 2014 Yehuda Katz, Tom Dale, Stefan Penner and contributors (Conversion to ES6 API by Jake Archibald)4 * @license Licensed under MIT license5 * See https://raw.githubusercontent.com/jakearchibald/es6-promise/master/LICENSE6 * @version 3.2.17 */8(function() {9 "use strict";10 function lib$es6$promise$utils$$objectOrFunction(x) {11 return typeof x === 'function' || (typeof x === 'object' && x !== null);12 }13 function lib$es6$promise$utils$$isFunction(x) {14 return typeof x === 'function';15 }16 function lib$es6$promise$utils$$isMaybeThenable(x) {17 return typeof x === 'object' && x !== null;18 }19 var lib$es6$promise$utils$$_isArray;20 if (!Array.isArray) {21 lib$es6$promise$utils$$_isArray = function (x) {22 return Object.prototype.toString.call(x) === '[object Array]';23 };24 } else {25 lib$es6$promise$utils$$_isArray = Array.isArray;26 }27 var lib$es6$promise$utils$$isArray = lib$es6$promise$utils$$_isArray;28 var lib$es6$promise$asap$$len = 0;29 var lib$es6$promise$asap$$vertxNext;30 var lib$es6$promise$asap$$customSchedulerFn;31 var lib$es6$promise$asap$$asap = function asap(callback, arg) {32 lib$es6$promise$asap$$queue[lib$es6$promise$asap$$len] = callback;33 lib$es6$promise$asap$$queue[lib$es6$promise$asap$$len + 1] = arg;34 lib$es6$promise$asap$$len += 2;35 if (lib$es6$promise$asap$$len === 2) {36 // If len is 2, that means that we need to schedule an async flush.37 // If additional callbacks are queued before the queue is flushed, they38 // will be processed by this flush that we are scheduling.39 if (lib$es6$promise$asap$$customSchedulerFn) {40 lib$es6$promise$asap$$customSchedulerFn(lib$es6$promise$asap$$flush);41 } else {42 lib$es6$promise$asap$$scheduleFlush();43 }44 }45 }46 function lib$es6$promise$asap$$setScheduler(scheduleFn) {47 lib$es6$promise$asap$$customSchedulerFn = scheduleFn;48 }49 function lib$es6$promise$asap$$setAsap(asapFn) {50 lib$es6$promise$asap$$asap = asapFn;51 }52 var lib$es6$promise$asap$$browserWindow = (typeof window !== 'undefined') ? window : undefined;53 var lib$es6$promise$asap$$browserGlobal = lib$es6$promise$asap$$browserWindow || {};54 var lib$es6$promise$asap$$BrowserMutationObserver = lib$es6$promise$asap$$browserGlobal.MutationObserver || lib$es6$promise$asap$$browserGlobal.WebKitMutationObserver;55 var lib$es6$promise$asap$$isNode = typeof self === 'undefined' && typeof process !== 'undefined' && {}.toString.call(process) === '[object process]';56 // test for web worker but not in IE1057 var lib$es6$promise$asap$$isWorker = typeof Uint8ClampedArray !== 'undefined' &&58 typeof importScripts !== 'undefined' &&59 typeof MessageChannel !== 'undefined';60 // node61 function lib$es6$promise$asap$$useNextTick() {62 // node version 0.10.x displays a deprecation warning when nextTick is used recursively63 // see https://github.com/cujojs/when/issues/410 for details64 return function() {65 process.nextTick(lib$es6$promise$asap$$flush);66 };67 }68 // vertx69 function lib$es6$promise$asap$$useVertxTimer() {70 return function() {71 lib$es6$promise$asap$$vertxNext(lib$es6$promise$asap$$flush);72 };73 }74 function lib$es6$promise$asap$$useMutationObserver() {75 var iterations = 0;76 var observer = new lib$es6$promise$asap$$BrowserMutationObserver(lib$es6$promise$asap$$flush);77 var node = document.createTextNode('');78 observer.observe(node, { characterData: true });79 return function() {80 node.data = (iterations = ++iterations % 2);81 };82 }83 // web worker84 function lib$es6$promise$asap$$useMessageChannel() {85 var channel = new MessageChannel();86 channel.port1.onmessage = lib$es6$promise$asap$$flush;87 return function () {88 channel.port2.postMessage(0);89 };90 }91 function lib$es6$promise$asap$$useSetTimeout() {92 return function() {93 setTimeout(lib$es6$promise$asap$$flush, 1);94 };95 }96 var lib$es6$promise$asap$$queue = new Array(1000);97 function lib$es6$promise$asap$$flush() {98 for (var i = 0; i < lib$es6$promise$asap$$len; i+=2) {99 var callback = lib$es6$promise$asap$$queue[i];100 var arg = lib$es6$promise$asap$$queue[i+1];101 callback(arg);102 lib$es6$promise$asap$$queue[i] = undefined;103 lib$es6$promise$asap$$queue[i+1] = undefined;104 }105 lib$es6$promise$asap$$len = 0;106 }107 function lib$es6$promise$asap$$attemptVertx() {108 try {109 var r = require;110 var vertx = r('vertx');111 lib$es6$promise$asap$$vertxNext = vertx.runOnLoop || vertx.runOnContext;112 return lib$es6$promise$asap$$useVertxTimer();113 } catch(e) {114 return lib$es6$promise$asap$$useSetTimeout();115 }116 }117 var lib$es6$promise$asap$$scheduleFlush;118 // Decide what async method to use to triggering processing of queued callbacks:119 if (lib$es6$promise$asap$$isNode) {120 lib$es6$promise$asap$$scheduleFlush = lib$es6$promise$asap$$useNextTick();121 } else if (lib$es6$promise$asap$$BrowserMutationObserver) {122 lib$es6$promise$asap$$scheduleFlush = lib$es6$promise$asap$$useMutationObserver();123 } else if (lib$es6$promise$asap$$isWorker) {124 lib$es6$promise$asap$$scheduleFlush = lib$es6$promise$asap$$useMessageChannel();125 } else if (lib$es6$promise$asap$$browserWindow === undefined && typeof require === 'function') {126 lib$es6$promise$asap$$scheduleFlush = lib$es6$promise$asap$$attemptVertx();127 } else {128 lib$es6$promise$asap$$scheduleFlush = lib$es6$promise$asap$$useSetTimeout();129 }130 function lib$es6$promise$then$$then(onFulfillment, onRejection) {131 var parent = this;132 var child = new this.constructor(lib$es6$promise$$internal$$noop);133 if (child[lib$es6$promise$$internal$$PROMISE_ID] === undefined) {134 lib$es6$promise$$internal$$makePromise(child);135 }136 var state = parent._state;137 if (state) {138 var callback = arguments[state - 1];139 lib$es6$promise$asap$$asap(function(){140 lib$es6$promise$$internal$$invokeCallback(state, child, callback, parent._result);141 });142 } else {143 lib$es6$promise$$internal$$subscribe(parent, child, onFulfillment, onRejection);144 }145 return child;146 }147 var lib$es6$promise$then$$default = lib$es6$promise$then$$then;148 function lib$es6$promise$promise$resolve$$resolve(object) {149 /*jshint validthis:true */150 var Constructor = this;151 if (object && typeof object === 'object' && object.constructor === Constructor) {152 return object;153 }154 var promise = new Constructor(lib$es6$promise$$internal$$noop);155 lib$es6$promise$$internal$$resolve(promise, object);156 return promise;157 }158 var lib$es6$promise$promise$resolve$$default = lib$es6$promise$promise$resolve$$resolve;159 var lib$es6$promise$$internal$$PROMISE_ID = Math.random().toString(36).substring(16);160 function lib$es6$promise$$internal$$noop() {}161 var lib$es6$promise$$internal$$PENDING = void 0;162 var lib$es6$promise$$internal$$FULFILLED = 1;163 var lib$es6$promise$$internal$$REJECTED = 2;164 var lib$es6$promise$$internal$$GET_THEN_ERROR = new lib$es6$promise$$internal$$ErrorObject();165 function lib$es6$promise$$internal$$selfFulfillment() {166 return new TypeError("You cannot resolve a promise with itself");167 }168 function lib$es6$promise$$internal$$cannotReturnOwn() {169 return new TypeError('A promises callback cannot return that same promise.');170 }171 function lib$es6$promise$$internal$$getThen(promise) {172 try {173 return promise.then;174 } catch(error) {175 lib$es6$promise$$internal$$GET_THEN_ERROR.error = error;176 return lib$es6$promise$$internal$$GET_THEN_ERROR;177 }178 }179 function lib$es6$promise$$internal$$tryThen(then, value, fulfillmentHandler, rejectionHandler) {180 try {181 then.call(value, fulfillmentHandler, rejectionHandler);182 } catch(e) {183 return e;184 }185 }186 function lib$es6$promise$$internal$$handleForeignThenable(promise, thenable, then) {187 lib$es6$promise$asap$$asap(function(promise) {188 var sealed = false;189 var error = lib$es6$promise$$internal$$tryThen(then, thenable, function(value) {190 if (sealed) { return; }191 sealed = true;192 if (thenable !== value) {193 lib$es6$promise$$internal$$resolve(promise, value);194 } else {195 lib$es6$promise$$internal$$fulfill(promise, value);196 }197 }, function(reason) {198 if (sealed) { return; }199 sealed = true;200 lib$es6$promise$$internal$$reject(promise, reason);201 }, 'Settle: ' + (promise._label || ' unknown promise'));202 if (!sealed && error) {203 sealed = true;204 lib$es6$promise$$internal$$reject(promise, error);205 }206 }, promise);207 }208 function lib$es6$promise$$internal$$handleOwnThenable(promise, thenable) {209 if (thenable._state === lib$es6$promise$$internal$$FULFILLED) {210 lib$es6$promise$$internal$$fulfill(promise, thenable._result);211 } else if (thenable._state === lib$es6$promise$$internal$$REJECTED) {212 lib$es6$promise$$internal$$reject(promise, thenable._result);213 } else {214 lib$es6$promise$$internal$$subscribe(thenable, undefined, function(value) {215 lib$es6$promise$$internal$$resolve(promise, value);216 }, function(reason) {217 lib$es6$promise$$internal$$reject(promise, reason);218 });219 }220 }221 function lib$es6$promise$$internal$$handleMaybeThenable(promise, maybeThenable, then) {222 if (maybeThenable.constructor === promise.constructor &&223 then === lib$es6$promise$then$$default &&224 constructor.resolve === lib$es6$promise$promise$resolve$$default) {225 lib$es6$promise$$internal$$handleOwnThenable(promise, maybeThenable);226 } else {227 if (then === lib$es6$promise$$internal$$GET_THEN_ERROR) {228 lib$es6$promise$$internal$$reject(promise, lib$es6$promise$$internal$$GET_THEN_ERROR.error);229 } else if (then === undefined) {230 lib$es6$promise$$internal$$fulfill(promise, maybeThenable);231 } else if (lib$es6$promise$utils$$isFunction(then)) {232 lib$es6$promise$$internal$$handleForeignThenable(promise, maybeThenable, then);233 } else {234 lib$es6$promise$$internal$$fulfill(promise, maybeThenable);235 }236 }237 }238 function lib$es6$promise$$internal$$resolve(promise, value) {239 if (promise === value) {240 lib$es6$promise$$internal$$reject(promise, lib$es6$promise$$internal$$selfFulfillment());241 } else if (lib$es6$promise$utils$$objectOrFunction(value)) {242 lib$es6$promise$$internal$$handleMaybeThenable(promise, value, lib$es6$promise$$internal$$getThen(value));243 } else {244 lib$es6$promise$$internal$$fulfill(promise, value);245 }246 }247 function lib$es6$promise$$internal$$publishRejection(promise) {248 if (promise._onerror) {249 promise._onerror(promise._result);250 }251 lib$es6$promise$$internal$$publish(promise);252 }253 function lib$es6$promise$$internal$$fulfill(promise, value) {254 if (promise._state !== lib$es6$promise$$internal$$PENDING) { return; }255 promise._result = value;256 promise._state = lib$es6$promise$$internal$$FULFILLED;257 if (promise._subscribers.length !== 0) {258 lib$es6$promise$asap$$asap(lib$es6$promise$$internal$$publish, promise);259 }260 }261 function lib$es6$promise$$internal$$reject(promise, reason) {262 if (promise._state !== lib$es6$promise$$internal$$PENDING) { return; }263 promise._state = lib$es6$promise$$internal$$REJECTED;264 promise._result = reason;265 lib$es6$promise$asap$$asap(lib$es6$promise$$internal$$publishRejection, promise);266 }267 function lib$es6$promise$$internal$$subscribe(parent, child, onFulfillment, onRejection) {268 var subscribers = parent._subscribers;269 var length = subscribers.length;270 parent._onerror = null;271 subscribers[length] = child;272 subscribers[length + lib$es6$promise$$internal$$FULFILLED] = onFulfillment;273 subscribers[length + lib$es6$promise$$internal$$REJECTED] = onRejection;274 if (length === 0 && parent._state) {275 lib$es6$promise$asap$$asap(lib$es6$promise$$internal$$publish, parent);276 }277 }278 function lib$es6$promise$$internal$$publish(promise) {279 var subscribers = promise._subscribers;280 var settled = promise._state;281 if (subscribers.length === 0) { return; }282 var child, callback, detail = promise._result;283 for (var i = 0; i < subscribers.length; i += 3) {284 child = subscribers[i];285 callback = subscribers[i + settled];286 if (child) {287 lib$es6$promise$$internal$$invokeCallback(settled, child, callback, detail);288 } else {289 callback(detail);290 }291 }292 promise._subscribers.length = 0;293 }294 function lib$es6$promise$$internal$$ErrorObject() {295 this.error = null;296 }297 var lib$es6$promise$$internal$$TRY_CATCH_ERROR = new lib$es6$promise$$internal$$ErrorObject();298 function lib$es6$promise$$internal$$tryCatch(callback, detail) {299 try {300 return callback(detail);301 } catch(e) {302 lib$es6$promise$$internal$$TRY_CATCH_ERROR.error = e;303 return lib$es6$promise$$internal$$TRY_CATCH_ERROR;304 }305 }306 function lib$es6$promise$$internal$$invokeCallback(settled, promise, callback, detail) {307 var hasCallback = lib$es6$promise$utils$$isFunction(callback),308 value, error, succeeded, failed;309 if (hasCallback) {310 value = lib$es6$promise$$internal$$tryCatch(callback, detail);311 if (value === lib$es6$promise$$internal$$TRY_CATCH_ERROR) {312 failed = true;313 error = value.error;314 value = null;315 } else {316 succeeded = true;317 }318 if (promise === value) {319 lib$es6$promise$$internal$$reject(promise, lib$es6$promise$$internal$$cannotReturnOwn());320 return;321 }322 } else {323 value = detail;324 succeeded = true;325 }326 if (promise._state !== lib$es6$promise$$internal$$PENDING) {327 // noop328 } else if (hasCallback && succeeded) {329 lib$es6$promise$$internal$$resolve(promise, value);330 } else if (failed) {331 lib$es6$promise$$internal$$reject(promise, error);332 } else if (settled === lib$es6$promise$$internal$$FULFILLED) {333 lib$es6$promise$$internal$$fulfill(promise, value);334 } else if (settled === lib$es6$promise$$internal$$REJECTED) {335 lib$es6$promise$$internal$$reject(promise, value);336 }337 }338 function lib$es6$promise$$internal$$initializePromise(promise, resolver) {339 try {340 resolver(function resolvePromise(value){341 lib$es6$promise$$internal$$resolve(promise, value);342 }, function rejectPromise(reason) {343 lib$es6$promise$$internal$$reject(promise, reason);344 });345 } catch(e) {346 lib$es6$promise$$internal$$reject(promise, e);347 }348 }349 var lib$es6$promise$$internal$$id = 0;350 function lib$es6$promise$$internal$$nextId() {351 return lib$es6$promise$$internal$$id++;352 }353 function lib$es6$promise$$internal$$makePromise(promise) {354 promise[lib$es6$promise$$internal$$PROMISE_ID] = lib$es6$promise$$internal$$id++;355 promise._state = undefined;356 promise._result = undefined;357 promise._subscribers = [];358 }359 function lib$es6$promise$promise$all$$all(entries) {360 return new lib$es6$promise$enumerator$$default(this, entries).promise;361 }362 var lib$es6$promise$promise$all$$default = lib$es6$promise$promise$all$$all;363 function lib$es6$promise$promise$race$$race(entries) {364 /*jshint validthis:true */365 var Constructor = this;366 if (!lib$es6$promise$utils$$isArray(entries)) {367 return new Constructor(function(resolve, reject) {368 reject(new TypeError('You must pass an array to race.'));369 });370 } else {371 return new Constructor(function(resolve, reject) {372 var length = entries.length;373 for (var i = 0; i < length; i++) {374 Constructor.resolve(entries[i]).then(resolve, reject);375 }376 });377 }378 }379 var lib$es6$promise$promise$race$$default = lib$es6$promise$promise$race$$race;380 function lib$es6$promise$promise$reject$$reject(reason) {381 /*jshint validthis:true */382 var Constructor = this;383 var promise = new Constructor(lib$es6$promise$$internal$$noop);384 lib$es6$promise$$internal$$reject(promise, reason);385 return promise;386 }387 var lib$es6$promise$promise$reject$$default = lib$es6$promise$promise$reject$$reject;388 function lib$es6$promise$promise$$needsResolver() {389 throw new TypeError('You must pass a resolver function as the first argument to the promise constructor');390 }391 function lib$es6$promise$promise$$needsNew() {392 throw new TypeError("Failed to construct 'Promise': Please use the 'new' operator, this object constructor cannot be called as a function.");393 }394 var lib$es6$promise$promise$$default = lib$es6$promise$promise$$Promise;395 /**396 Promise objects represent the eventual result of an asynchronous operation. The397 primary way of interacting with a promise is through its `then` method, which398 registers callbacks to receive either a promise's eventual value or the reason399 why the promise cannot be fulfilled.400 Terminology401 -----------402 - `promise` is an object or function with a `then` method whose behavior conforms to this specification.403 - `thenable` is an object or function that defines a `then` method.404 - `value` is any legal JavaScript value (including undefined, a thenable, or a promise).405 - `exception` is a value that is thrown using the throw statement.406 - `reason` is a value that indicates why a promise was rejected.407 - `settled` the final resting state of a promise, fulfilled or rejected.408 A promise can be in one of three states: pending, fulfilled, or rejected.409 Promises that are fulfilled have a fulfillment value and are in the fulfilled410 state. Promises that are rejected have a rejection reason and are in the411 rejected state. A fulfillment value is never a thenable.412 Promises can also be said to *resolve* a value. If this value is also a413 promise, then the original promise's settled state will match the value's414 settled state. So a promise that *resolves* a promise that rejects will415 itself reject, and a promise that *resolves* a promise that fulfills will416 itself fulfill.417 Basic Usage:418 ------------419 ```js420 var promise = new Promise(function(resolve, reject) {421 // on success422 resolve(value);423 // on failure424 reject(reason);425 });426 promise.then(function(value) {427 // on fulfillment428 }, function(reason) {429 // on rejection430 });431 ```432 Advanced Usage:433 ---------------434 Promises shine when abstracting away asynchronous interactions such as435 `XMLHttpRequest`s.436 ```js437 function getJSON(url) {438 return new Promise(function(resolve, reject){439 var xhr = new XMLHttpRequest();440 xhr.open('GET', url);441 xhr.onreadystatechange = handler;442 xhr.responseType = 'json';443 xhr.setRequestHeader('Accept', 'application/json');444 xhr.send();445 function handler() {446 if (this.readyState === this.DONE) {447 if (this.status === 200) {448 resolve(this.response);449 } else {450 reject(new Error('getJSON: `' + url + '` failed with status: [' + this.status + ']'));451 }452 }453 };454 });455 }456 getJSON('/posts.json').then(function(json) {457 // on fulfillment458 }, function(reason) {459 // on rejection460 });461 ```462 Unlike callbacks, promises are great composable primitives.463 ```js464 Promise.all([465 getJSON('/posts'),466 getJSON('/comments')467 ]).then(function(values){468 values[0] // => postsJSON469 values[1] // => commentsJSON470 return values;471 });472 ```473 @class Promise474 @param {function} resolver475 Useful for tooling.476 @constructor477 */478 function lib$es6$promise$promise$$Promise(resolver) {479 this[lib$es6$promise$$internal$$PROMISE_ID] = lib$es6$promise$$internal$$nextId();480 this._result = this._state = undefined;481 this._subscribers = [];482 if (lib$es6$promise$$internal$$noop !== resolver) {483 typeof resolver !== 'function' && lib$es6$promise$promise$$needsResolver();484 this instanceof lib$es6$promise$promise$$Promise ? lib$es6$promise$$internal$$initializePromise(this, resolver) : lib$es6$promise$promise$$needsNew();485 }486 }487 lib$es6$promise$promise$$Promise.all = lib$es6$promise$promise$all$$default;488 lib$es6$promise$promise$$Promise.race = lib$es6$promise$promise$race$$default;489 lib$es6$promise$promise$$Promise.resolve = lib$es6$promise$promise$resolve$$default;490 lib$es6$promise$promise$$Promise.reject = lib$es6$promise$promise$reject$$default;491 lib$es6$promise$promise$$Promise._setScheduler = lib$es6$promise$asap$$setScheduler;492 lib$es6$promise$promise$$Promise._setAsap = lib$es6$promise$asap$$setAsap;493 lib$es6$promise$promise$$Promise._asap = lib$es6$promise$asap$$asap;494 lib$es6$promise$promise$$Promise.prototype = {495 constructor: lib$es6$promise$promise$$Promise,496 /**497 The primary way of interacting with a promise is through its `then` method,498 which registers callbacks to receive either a promise's eventual value or the499 reason why the promise cannot be fulfilled.500 ```js501 findUser().then(function(user){502 // user is available503 }, function(reason){504 // user is unavailable, and you are given the reason why505 });506 ```507 Chaining508 --------509 The return value of `then` is itself a promise. This second, 'downstream'510 promise is resolved with the return value of the first promise's fulfillment511 or rejection handler, or rejected if the handler throws an exception.512 ```js513 findUser().then(function (user) {514 return user.name;515 }, function (reason) {516 return 'default name';517 }).then(function (userName) {518 // If `findUser` fulfilled, `userName` will be the user's name, otherwise it519 // will be `'default name'`520 });521 findUser().then(function (user) {522 throw new Error('Found user, but still unhappy');523 }, function (reason) {524 throw new Error('`findUser` rejected and we're unhappy');525 }).then(function (value) {526 // never reached527 }, function (reason) {528 // if `findUser` fulfilled, `reason` will be 'Found user, but still unhappy'.529 // If `findUser` rejected, `reason` will be '`findUser` rejected and we're unhappy'.530 });531 ```532 If the downstream promise does not specify a rejection handler, rejection reasons will be propagated further downstream.533 ```js534 findUser().then(function (user) {535 throw new PedagogicalException('Upstream error');536 }).then(function (value) {537 // never reached538 }).then(function (value) {539 // never reached540 }, function (reason) {541 // The `PedgagocialException` is propagated all the way down to here542 });543 ```544 Assimilation545 ------------546 Sometimes the value you want to propagate to a downstream promise can only be547 retrieved asynchronously. This can be achieved by returning a promise in the548 fulfillment or rejection handler. The downstream promise will then be pending549 until the returned promise is settled. This is called *assimilation*.550 ```js551 findUser().then(function (user) {552 return findCommentsByAuthor(user);553 }).then(function (comments) {554 // The user's comments are now available555 });556 ```557 If the assimliated promise rejects, then the downstream promise will also reject.558 ```js559 findUser().then(function (user) {560 return findCommentsByAuthor(user);561 }).then(function (comments) {562 // If `findCommentsByAuthor` fulfills, we'll have the value here563 }, function (reason) {564 // If `findCommentsByAuthor` rejects, we'll have the reason here565 });566 ```567 Simple Example568 --------------569 Synchronous Example570 ```javascript571 var result;572 try {573 result = findResult();574 // success575 } catch(reason) {576 // failure577 }578 ```579 Errback Example580 ```js581 findResult(function(result, err){582 if (err) {583 // failure584 } else {585 // success586 }587 });588 ```589 Promise Example;590 ```javascript591 findResult().then(function(result){592 // success593 }, function(reason){594 // failure595 });596 ```597 Advanced Example598 --------------599 Synchronous Example600 ```javascript601 var author, books;602 try {603 author = findAuthor();604 books = findBooksByAuthor(author);605 // success606 } catch(reason) {607 // failure608 }609 ```610 Errback Example611 ```js612 function foundBooks(books) {613 }614 function failure(reason) {615 }616 findAuthor(function(author, err){617 if (err) {618 failure(err);619 // failure620 } else {621 try {622 findBoooksByAuthor(author, function(books, err) {623 if (err) {624 failure(err);625 } else {626 try {627 foundBooks(books);628 } catch(reason) {629 failure(reason);630 }631 }632 });633 } catch(error) {634 failure(err);635 }636 // success637 }638 });639 ```640 Promise Example;641 ```javascript642 findAuthor().643 then(findBooksByAuthor).644 then(function(books){645 // found books646 }).catch(function(reason){647 // something went wrong648 });649 ```650 @method then651 @param {Function} onFulfilled652 @param {Function} onRejected653 Useful for tooling.654 @return {Promise}655 */656 then: lib$es6$promise$then$$default,657 /**658 `catch` is simply sugar for `then(undefined, onRejection)` which makes it the same659 as the catch block of a try/catch statement.660 ```js661 function findAuthor(){662 throw new Error('couldn't find that author');663 }664 // synchronous665 try {666 findAuthor();667 } catch(reason) {668 // something went wrong669 }670 // async with promises671 findAuthor().catch(function(reason){672 // something went wrong673 });674 ```675 @method catch676 @param {Function} onRejection677 Useful for tooling.678 @return {Promise}679 */680 'catch': function(onRejection) {681 return this.then(null, onRejection);682 }683 };684 var lib$es6$promise$enumerator$$default = lib$es6$promise$enumerator$$Enumerator;685 function lib$es6$promise$enumerator$$Enumerator(Constructor, input) {686 this._instanceConstructor = Constructor;687 this.promise = new Constructor(lib$es6$promise$$internal$$noop);688 if (!this.promise[lib$es6$promise$$internal$$PROMISE_ID]) {689 lib$es6$promise$$internal$$makePromise(this.promise);690 }691 if (Array.isArray(input)) {692 this._input = input;693 this.length = input.length;694 this._remaining = input.length;695 this._result = new Array(this.length);696 if (this.length === 0) {697 lib$es6$promise$$internal$$fulfill(this.promise, this._result);698 } else {699 this.length = this.length || 0;700 this._enumerate();701 if (this._remaining === 0) {702 lib$es6$promise$$internal$$fulfill(this.promise, this._result);703 }704 }705 } else {706 lib$es6$promise$$internal$$reject(this.promise, lib$es6$promise$enumerator$$validationError());707 }708 }709 function lib$es6$promise$enumerator$$validationError() {710 return new Error('Array Methods must be provided an Array');711 }712 lib$es6$promise$enumerator$$Enumerator.prototype._enumerate = function() {713 var length = this.length;714 var input = this._input;715 for (var i = 0; this._state === lib$es6$promise$$internal$$PENDING && i < length; i++) {716 this._eachEntry(input[i], i);717 }718 };719 lib$es6$promise$enumerator$$Enumerator.prototype._eachEntry = function(entry, i) {720 var c = this._instanceConstructor;721 var resolve = c.resolve;722 if (resolve === lib$es6$promise$promise$resolve$$default) {723 var then = lib$es6$promise$$internal$$getThen(entry);724 if (then === lib$es6$promise$then$$default &&725 entry._state !== lib$es6$promise$$internal$$PENDING) {726 this._settledAt(entry._state, i, entry._result);727 } else if (typeof then !== 'function') {728 this._remaining--;729 this._result[i] = entry;730 } else if (c === lib$es6$promise$promise$$default) {731 var promise = new c(lib$es6$promise$$internal$$noop);732 lib$es6$promise$$internal$$handleMaybeThenable(promise, entry, then);733 this._willSettleAt(promise, i);734 } else {735 this._willSettleAt(new c(function(resolve) { resolve(entry); }), i);736 }737 } else {738 this._willSettleAt(resolve(entry), i);739 }740 };741 lib$es6$promise$enumerator$$Enumerator.prototype._settledAt = function(state, i, value) {742 var promise = this.promise;743 if (promise._state === lib$es6$promise$$internal$$PENDING) {744 this._remaining--;745 if (state === lib$es6$promise$$internal$$REJECTED) {746 lib$es6$promise$$internal$$reject(promise, value);747 } else {748 this._result[i] = value;749 }750 }751 if (this._remaining === 0) {752 lib$es6$promise$$internal$$fulfill(promise, this._result);753 }754 };755 lib$es6$promise$enumerator$$Enumerator.prototype._willSettleAt = function(promise, i) {756 var enumerator = this;757 lib$es6$promise$$internal$$subscribe(promise, undefined, function(value) {758 enumerator._settledAt(lib$es6$promise$$internal$$FULFILLED, i, value);759 }, function(reason) {760 enumerator._settledAt(lib$es6$promise$$internal$$REJECTED, i, reason);761 });762 };763 function lib$es6$promise$polyfill$$polyfill() {764 var local;765 if (typeof global !== 'undefined') {766 local = global;767 } else if (typeof self !== 'undefined') {768 local = self;769 } else {770 try {771 local = Function('return this')();772 } catch (e) {773 throw new Error('polyfill failed because global object is unavailable in this environment');774 }775 }776 var P = local.Promise;777 if (P && Object.prototype.toString.call(P.resolve()) === '[object Promise]' && !P.cast) {778 return;779 }780 local.Promise = lib$es6$promise$promise$$default;781 }782 var lib$es6$promise$polyfill$$default = lib$es6$promise$polyfill$$polyfill;783 var lib$es6$promise$umd$$ES6Promise = {784 'Promise': lib$es6$promise$promise$$default,785 'polyfill': lib$es6$promise$polyfill$$default786 };787 /* global define:true module:true window: true */788 if (typeof define === 'function' && define['amd']) {789 define(function() { return lib$es6$promise$umd$$ES6Promise; });790 } else if (typeof module !== 'undefined' && module['exports']) {791 module['exports'] = lib$es6$promise$umd$$ES6Promise;792 } else if (typeof this !== 'undefined') {793 this['ES6Promise'] = lib$es6$promise$umd$$ES6Promise;794 }795 lib$es6$promise$polyfill$$default();...

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promises.js

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1// Copyright 2013 the V8 project authors. All rights reserved.2// Redistribution and use in source and binary forms, with or without3// modification, are permitted provided that the following conditions are4// met:5//6// * Redistributions of source code must retain the above copyright7// notice, this list of conditions and the following disclaimer.8// * Redistributions in binary form must reproduce the above9// copyright notice, this list of conditions and the following10// disclaimer in the documentation and/or other materials provided11// with the distribution.12// * Neither the name of Google Inc. nor the names of its13// contributors may be used to endorse or promote products derived14// from this software without specific prior written permission.15//16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.27// Flags: --allow-natives-syntax --promise-extra28// Make sure we don't rely on functions patchable by monkeys.29var call = Function.prototype.call.call.bind(Function.prototype.call)30var getOwnPropertyNames = Object.getOwnPropertyNames;31var defineProperty = Object.defineProperty;32var numberPrototype = Number.prototype;33var symbolIterator = Symbol.iterator;34(function() {35 // Test before clearing global (fails otherwise)36 assertEquals("[object Promise]",37 Object.prototype.toString.call(new Promise(function() {})));38})();39function clear(o) {40 if (o === null || (typeof o !== 'object' && typeof o !== 'function')) return41 clear(o.__proto__)42 var properties = getOwnPropertyNames(o)43 for (var i in properties) {44 // Do not clobber Object.prototype.toString, which is used by tests.45 if (properties[i] === "toString") continue;46 clearProp(o, properties[i])47 }48}49function clearProp(o, name) {50 var poisoned = {caller: 0, callee: 0, arguments: 0}51 try {52 var x = o[name]53 o[name] = undefined54 clear(x)55 } catch(e) {} // assertTrue(name in poisoned) }56}57// Find intrinsics and null them out.58var globals = Object.getOwnPropertyNames(this)59var whitelist = {60 Promise: true,61 TypeError: true,62 String: true,63 JSON: true,64 Error: true,65 MjsUnitAssertionError: true66};67for (var i in globals) {68 var name = globals[i]69 if (name in whitelist || name[0] === name[0].toLowerCase()) delete globals[i]70}71for (var i in globals) {72 if (globals[i]) clearProp(this, globals[i])73}74var asyncAssertsExpected = 0;75function assertAsyncRan() { ++asyncAssertsExpected }76function assertAsync(b, s) {77 if (b) {78 print(s, "succeeded")79 } else {80 %AbortJS(s + " FAILED!") // Simply throwing here will have no effect.81 }82 --asyncAssertsExpected83}84function assertLater(f, name) {85 assertFalse(f()); // should not be true synchronously86 ++asyncAssertsExpected;87 var iterations = 0;88 function runAssertion() {89 if (f()) {90 print(name, "succeeded");91 --asyncAssertsExpected;92 } else if (iterations++ < 10) {93 %EnqueueMicrotask(runAssertion);94 } else {95 %AbortJS(name + " FAILED!");96 }97 }98 %EnqueueMicrotask(runAssertion);99}100function assertAsyncDone(iteration) {101 var iteration = iteration || 0;102 %EnqueueMicrotask(function() {103 if (asyncAssertsExpected === 0)104 assertAsync(true, "all")105 else if (iteration > 10) // Shouldn't take more.106 assertAsync(false, "all... " + asyncAssertsExpected)107 else108 assertAsyncDone(iteration + 1)109 });110}111(function() {112 assertThrows(function() { Promise(function() {}) }, TypeError)113})();114(function() {115 assertTrue(new Promise(function() {}) instanceof Promise)116})();117(function() {118 assertThrows(function() { new Promise(5) }, TypeError)119})();120(function() {121 assertDoesNotThrow(function() { new Promise(function() { throw 5 }) })122})();123(function() {124 (new Promise(function() { throw 5 })).chain(125 assertUnreachable,126 function(r) { assertAsync(r === 5, "new-throw") }127 )128 assertAsyncRan()129})();130(function() {131 Promise.accept(5);132 Promise.accept(5).chain(undefined, assertUnreachable).chain(133 function(x) { assertAsync(x === 5, "resolved/chain-nohandler") },134 assertUnreachable135 )136 assertAsyncRan()137})();138(function() {139 Promise.reject(5).chain(assertUnreachable, undefined).chain(140 assertUnreachable,141 function(r) { assertAsync(r === 5, "rejected/chain-nohandler") }142 )143 assertAsyncRan()144})();145(function() {146 Promise.accept(5).then(undefined, assertUnreachable).chain(147 function(x) { assertAsync(x === 5, "resolved/then-nohandler-undefined") },148 assertUnreachable149 )150 assertAsyncRan()151 Promise.accept(6).then(null, assertUnreachable).chain(152 function(x) { assertAsync(x === 6, "resolved/then-nohandler-null") },153 assertUnreachable154 )155 assertAsyncRan()156})();157(function() {158 Promise.reject(5).then(assertUnreachable, undefined).chain(159 assertUnreachable,160 function(r) { assertAsync(r === 5, "rejected/then-nohandler-undefined") }161 )162 assertAsyncRan()163 Promise.reject(6).then(assertUnreachable, null).chain(164 assertUnreachable,165 function(r) { assertAsync(r === 6, "rejected/then-nohandler-null") }166 )167 assertAsyncRan()168})();169(function() {170 var p1 = Promise.accept(5)171 var p2 = Promise.accept(p1)172 var p3 = Promise.accept(p2)173 // Note: Chain now has then-style semantics, here and in future tests.174 p3.chain(175 function(x) { assertAsync(x === 5, "resolved/chain") },176 assertUnreachable177 )178 assertAsyncRan()179})();180(function() {181 var p1 = Promise.accept(5)182 var p2 = Promise.accept(p1)183 var p3 = Promise.accept(p2)184 p3.then(185 function(x) { assertAsync(x === 5, "resolved/then") },186 assertUnreachable187 )188 assertAsyncRan()189})();190(function() {191 var p1 = Promise.reject(5)192 var p2 = Promise.accept(p1)193 var p3 = Promise.accept(p2)194 p3.chain(195 assertUnreachable,196 function(x) { assertAsync(x === 5, "rejected/chain") }197 )198 assertAsyncRan()199})();200(function() {201 var p1 = Promise.reject(5)202 var p2 = Promise.accept(p1)203 var p3 = Promise.accept(p2)204 p3.then(205 assertUnreachable,206 function(x) { assertAsync(x === 5, "rejected/then") }207 )208 assertAsyncRan()209})();210(function() {211 var p1 = Promise.accept(5)212 var p2 = Promise.accept(p1)213 var p3 = Promise.accept(p2)214 p3.chain(function(x) { return x }, assertUnreachable).chain(215 function(x) { assertAsync(x === 5, "resolved/chain/chain") },216 assertUnreachable217 )218 assertAsyncRan()219})();220(function() {221 var p1 = Promise.accept(5)222 var p2 = Promise.accept(p1)223 var p3 = Promise.accept(p2)224 p3.chain(function(x) { return x }, assertUnreachable).then(225 function(x) { assertAsync(x === 5, "resolved/chain/then") },226 assertUnreachable227 )228 assertAsyncRan()229})();230(function() {231 var p1 = Promise.accept(5)232 var p2 = Promise.accept(p1)233 var p3 = Promise.accept(p2)234 p3.chain(function(x) { return 6 }, assertUnreachable).chain(235 function(x) { assertAsync(x === 6, "resolved/chain/chain2") },236 assertUnreachable237 )238 assertAsyncRan()239})();240(function() {241 var p1 = Promise.accept(5)242 var p2 = Promise.accept(p1)243 var p3 = Promise.accept(p2)244 p3.chain(function(x) { return 6 }, assertUnreachable).then(245 function(x) { assertAsync(x === 6, "resolved/chain/then2") },246 assertUnreachable247 )248 assertAsyncRan()249})();250(function() {251 var p1 = Promise.accept(5)252 var p2 = Promise.accept(p1)253 var p3 = Promise.accept(p2)254 p3.then(function(x) { return x + 1 }, assertUnreachable).chain(255 function(x) { assertAsync(x === 6, "resolved/then/chain") },256 assertUnreachable257 )258 assertAsyncRan()259})();260(function() {261 var p1 = Promise.accept(5)262 var p2 = Promise.accept(p1)263 var p3 = Promise.accept(p2)264 p3.then(function(x) { return x + 1 }, assertUnreachable).then(265 function(x) { assertAsync(x === 6, "resolved/then/then") },266 assertUnreachable267 )268 assertAsyncRan()269})();270(function() {271 var p1 = Promise.accept(5)272 var p2 = Promise.accept(p1)273 var p3 = Promise.accept(p2)274 p3.then(function(x){ return Promise.accept(x+1) }, assertUnreachable).chain(275 function(x) { assertAsync(x === 6, "resolved/then/chain2") },276 assertUnreachable277 )278 assertAsyncRan()279})();280(function() {281 var p1 = Promise.accept(5)282 var p2 = Promise.accept(p1)283 var p3 = Promise.accept(p2)284 p3.then(function(x) { return Promise.accept(x+1) }, assertUnreachable).then(285 function(x) { assertAsync(x === 6, "resolved/then/then2") },286 assertUnreachable287 )288 assertAsyncRan()289})();290(function() {291 var p1 = Promise.accept(5)292 var p2 = Promise.accept(p1)293 var p3 = Promise.accept(p2)294 p3.chain(function(x) { throw 6 }, assertUnreachable).chain(295 assertUnreachable,296 function(x) { assertAsync(x === 6, "resolved/chain-throw/chain") }297 )298 assertAsyncRan()299})();300(function() {301 var p1 = Promise.accept(5)302 var p2 = Promise.accept(p1)303 var p3 = Promise.accept(p2)304 p3.chain(function(x) { throw 6 }, assertUnreachable).then(305 assertUnreachable,306 function(x) { assertAsync(x === 6, "resolved/chain-throw/then") }307 )308 assertAsyncRan()309})();310(function() {311 var p1 = Promise.accept(5)312 var p2 = Promise.accept(p1)313 var p3 = Promise.accept(p2)314 p3.then(function(x) { throw 6 }, assertUnreachable).chain(315 assertUnreachable,316 function(x) { assertAsync(x === 6, "resolved/then-throw/chain") }317 )318 assertAsyncRan()319})();320(function() {321 var p1 = Promise.accept(5)322 var p2 = Promise.accept(p1)323 var p3 = Promise.accept(p2)324 p3.then(function(x) { throw 6 }, assertUnreachable).then(325 assertUnreachable,326 function(x) { assertAsync(x === 6, "resolved/then-throw/then") }327 )328 assertAsyncRan()329})();330(function() {331 var p1 = Promise.accept(5)332 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}333 var p3 = Promise.accept(p2)334 p3.chain(335 function(x) { assertAsync(x === 5, "resolved/thenable/chain") },336 assertUnreachable337 )338 assertAsyncRan()339})();340(function() {341 var p1 = Promise.accept(5)342 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}343 var p3 = Promise.accept(p2)344 p3.then(345 function(x) { assertAsync(x === 5, "resolved/thenable/then") },346 assertUnreachable347 )348 assertAsyncRan()349})();350(function() {351 var p1 = Promise.reject(5)352 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}353 var p3 = Promise.accept(p2)354 p3.chain(355 assertUnreachable,356 function(x) { assertAsync(x === 5, "rejected/thenable/chain") }357 )358 assertAsyncRan()359})();360(function() {361 var p1 = Promise.reject(5)362 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}363 var p3 = Promise.accept(p2)364 p3.then(365 assertUnreachable,366 function(x) { assertAsync(x === 5, "rejected/thenable/then") }367 )368 assertAsyncRan()369})();370(function() {371 var deferred = Promise.defer()372 var p1 = deferred.promise373 var p2 = Promise.accept(p1)374 var p3 = Promise.accept(p2)375 p3.chain(376 function(x) { assertAsync(x === 5, "chain/resolve") },377 assertUnreachable378 )379 deferred.resolve(5)380 assertAsyncRan()381})();382(function() {383 var deferred = Promise.defer()384 var p1 = deferred.promise385 var p2 = Promise.resolve(p1)386 var p3 = Promise.resolve(p2)387 p3.then(388 function(x) { assertAsync(x === 5, "then/resolve") },389 assertUnreachable390 )391 deferred.resolve(5)392 assertAsyncRan()393})();394(function() {395 var deferred = Promise.defer()396 var p1 = deferred.promise397 var p2 = Promise.accept(p1)398 var p3 = Promise.accept(p2)399 p3.chain(400 assertUnreachable,401 function(x) { assertAsync(x === 5, "chain/reject") }402 )403 deferred.reject(5)404 assertAsyncRan()405})();406(function() {407 var deferred = Promise.defer()408 var p1 = deferred.promise409 var p2 = Promise.accept(p1)410 var p3 = Promise.accept(p2)411 p3.then(412 assertUnreachable,413 function(x) { assertAsync(x === 5, "then/reject") }414 )415 deferred.reject(5)416 assertAsyncRan()417})();418(function() {419 var deferred = Promise.defer()420 var p1 = deferred.promise421 var p2 = p1.then(1, 2)422 p2.then(423 function(x) { assertAsync(x === 5, "then/resolve-non-function") },424 assertUnreachable425 )426 deferred.resolve(5)427 assertAsyncRan()428})();429(function() {430 var deferred = Promise.defer()431 var p1 = deferred.promise432 var p2 = p1.then(1, 2)433 p2.then(434 assertUnreachable,435 function(x) { assertAsync(x === 5, "then/reject-non-function") }436 )437 deferred.reject(5)438 assertAsyncRan()439})();440(function() {441 var deferred = Promise.defer()442 var p1 = deferred.promise443 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}444 var p3 = Promise.accept(p2)445 p3.chain(446 function(x) { assertAsync(x === 5, "chain/resolve/thenable") },447 assertUnreachable448 )449 deferred.resolve(5)450 assertAsyncRan()451})();452(function() {453 var deferred = Promise.defer()454 var p1 = deferred.promise455 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}456 var p3 = Promise.accept(p2)457 p3.then(458 function(x) { assertAsync(x === 5, "then/resolve/thenable") },459 assertUnreachable460 )461 deferred.resolve(5)462 assertAsyncRan()463})();464(function() {465 var deferred = Promise.defer()466 var p1 = deferred.promise467 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}468 var p3 = Promise.accept(p2)469 p3.chain(470 assertUnreachable,471 function(x) { assertAsync(x === 5, "chain/reject/thenable") }472 )473 deferred.reject(5)474 assertAsyncRan()475})();476(function() {477 var deferred = Promise.defer()478 var p1 = deferred.promise479 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}480 var p3 = Promise.accept(p2)481 p3.then(482 assertUnreachable,483 function(x) { assertAsync(x === 5, "then/reject/thenable") }484 )485 deferred.reject(5)486 assertAsyncRan()487})();488(function() {489 var p1 = Promise.accept(5)490 var p2 = Promise.accept(p1)491 var deferred = Promise.defer()492 var p3 = deferred.promise493 p3.chain(494 function(x) { assertAsync(x === 5, "chain/resolve2") },495 assertUnreachable496 )497 deferred.resolve(p2)498 assertAsyncRan()499})();500(function() {501 var p1 = Promise.accept(5)502 var p2 = Promise.accept(p1)503 var deferred = Promise.defer()504 var p3 = deferred.promise505 p3.then(506 function(x) { assertAsync(x === 5, "then/resolve2") },507 assertUnreachable508 )509 deferred.resolve(p2)510 assertAsyncRan()511})();512(function() {513 var p1 = Promise.accept(5)514 var p2 = Promise.accept(p1)515 var deferred = Promise.defer()516 var p3 = deferred.promise517 p3.chain(518 assertUnreachable,519 function(x) { assertAsync(x === 5, "chain/reject2") }520 )521 deferred.reject(5)522 assertAsyncRan()523})();524(function() {525 var p1 = Promise.accept(5)526 var p2 = Promise.accept(p1)527 var deferred = Promise.defer()528 var p3 = deferred.promise529 p3.then(530 assertUnreachable,531 function(x) { assertAsync(x === 5, "then/reject2") }532 )533 deferred.reject(5)534 assertAsyncRan()535})();536(function() {537 var p1 = Promise.accept(5)538 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}539 var deferred = Promise.defer()540 var p3 = deferred.promise541 p3.chain(542 function(x) { assertAsync(x === 5, "chain/resolve/thenable2") },543 assertUnreachable544 )545 deferred.resolve(p2)546 assertAsyncRan()547})();548(function() {549 var p1 = Promise.accept(5)550 var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}551 var deferred = Promise.defer()552 var p3 = deferred.promise553 p3.then(554 function(x) { assertAsync(x === 5, "then/resolve/thenable2") },555 assertUnreachable556 )557 deferred.resolve(p2)558 assertAsyncRan()559})();560(function() {561 var p1 = Promise.accept(0)562 var p2 = p1.chain(function(x) { return p2 }, assertUnreachable)563 p2.chain(564 assertUnreachable,565 function(r) { assertAsync(r instanceof TypeError, "cyclic/chain") }566 )567 assertAsyncRan()568})();569(function() {570 var p1 = Promise.accept(0)571 var p2 = p1.then(function(x) { return p2 }, assertUnreachable)572 p2.chain(573 assertUnreachable,574 function(r) { assertAsync(r instanceof TypeError, "cyclic/then") }575 )576 assertAsyncRan()577})();578(function() {579 var deferred = Promise.defer()580 var p = deferred.promise581 deferred.resolve(p)582 p.chain(583 assertUnreachable,584 function(r) { assertAsync(r instanceof TypeError, "cyclic/deferred/then") }585 )586 assertAsyncRan()587})();588(function() {589 var deferred = Promise.defer()590 var p = deferred.promise591 deferred.resolve(p)592 p.then(593 assertUnreachable,594 function(r) { assertAsync(r instanceof TypeError, "cyclic/deferred/then") }595 )596 assertAsyncRan()597})();598(function() {599 Promise.all([]).chain(600 function(x) { assertAsync(x.length === 0, "all/resolve/empty") },601 assertUnreachable602 )603 assertAsyncRan()604})();605(function() {606 function testPromiseAllNonIterable(value) {607 Promise.all(value).chain(608 assertUnreachable,609 function(r) {610 assertAsync(r instanceof TypeError, 'all/non iterable');611 });612 assertAsyncRan();613 }614 testPromiseAllNonIterable(null);615 testPromiseAllNonIterable(undefined);616 testPromiseAllNonIterable({});617 testPromiseAllNonIterable(42);618})();619(function() {620 var deferred = Promise.defer();621 var p = deferred.promise;622 function* f() {623 yield 1;624 yield p;625 yield 3;626 }627 Promise.all(f()).chain(628 function(x) {629 assertAsync(x.length === 3, "all/resolve/iterable");630 assertAsync(x[0] === 1, "all/resolve/iterable/0");631 assertAsync(x[1] === 2, "all/resolve/iterable/1");632 assertAsync(x[2] === 3, "all/resolve/iterable/2");633 },634 assertUnreachable);635 deferred.resolve(2);636 assertAsyncRan();637 assertAsyncRan();638 assertAsyncRan();639 assertAsyncRan();640})();641(function() {642 var deferred1 = Promise.defer()643 var p1 = deferred1.promise644 var deferred2 = Promise.defer()645 var p2 = deferred2.promise646 var deferred3 = Promise.defer()647 var p3 = deferred3.promise648 Promise.all([p1, p2, p3]).chain(649 function(x) {650 assertAsync(x.length === 3, "all/resolve")651 assertAsync(x[0] === 1, "all/resolve/0")652 assertAsync(x[1] === 2, "all/resolve/1")653 assertAsync(x[2] === 3, "all/resolve/2")654 },655 assertUnreachable656 )657 deferred1.resolve(1)658 deferred3.resolve(3)659 deferred2.resolve(2)660 assertAsyncRan()661 assertAsyncRan()662 assertAsyncRan()663 assertAsyncRan()664})();665(function() {666 var deferred = Promise.defer()667 var p1 = deferred.promise668 var p2 = Promise.accept(2)669 var p3 = Promise.defer().promise670 Promise.all([p1, p2, p3]).chain(671 assertUnreachable,672 assertUnreachable673 )674 deferred.resolve(1)675})();676(function() {677 var deferred1 = Promise.defer()678 var p1 = deferred1.promise679 var deferred2 = Promise.defer()680 var p2 = deferred2.promise681 var deferred3 = Promise.defer()682 var p3 = deferred3.promise683 Promise.all([p1, p2, p3]).chain(684 assertUnreachable,685 function(x) { assertAsync(x === 2, "all/reject") }686 )687 deferred1.resolve(1)688 deferred3.resolve(3)689 deferred2.reject(2)690 assertAsyncRan()691})();692(function() {693 'use strict';694 var getCalls = 0;695 var funcCalls = 0;696 var nextCalls = 0;697 defineProperty(numberPrototype, symbolIterator, {698 get: function() {699 assertEquals('number', typeof this);700 getCalls++;701 return function() {702 assertEquals('number', typeof this);703 funcCalls++;704 var n = this;705 var i = 0706 return {707 next() {708 nextCalls++;709 return {value: i++, done: i > n};710 }711 };712 };713 },714 configurable: true715 });716 Promise.all(3).chain(717 function(x) {718 assertAsync(x.length === 3, "all/iterable/number/length");719 assertAsync(x[0] === 0, "all/iterable/number/0");720 assertAsync(x[1] === 1, "all/iterable/number/1");721 assertAsync(x[2] === 2, "all/iterable/number/2");722 },723 assertUnreachable);724 delete numberPrototype[symbolIterator];725 assertEquals(getCalls, 1);726 assertEquals(funcCalls, 1);727 assertEquals(nextCalls, 3 + 1); // + 1 for {done: true}728 assertAsyncRan();729 assertAsyncRan();730 assertAsyncRan();731 assertAsyncRan();732})();733(function() {734 Promise.race([]).chain(735 assertUnreachable,736 assertUnreachable737 )738})();739(function() {740 var p1 = Promise.accept(1)741 var p2 = Promise.accept(2)742 var p3 = Promise.accept(3)743 Promise.race([p1, p2, p3]).chain(744 function(x) { assertAsync(x === 1, "resolved/one") },745 assertUnreachable746 )747 assertAsyncRan()748})();749(function() {750 var p1 = Promise.accept(1)751 var p2 = Promise.accept(2)752 var p3 = Promise.accept(3)753 Promise.race([0, p1, p2, p3]).chain(754 function(x) { assertAsync(x === 0, "resolved-const/one") },755 assertUnreachable756 )757 assertAsyncRan()758})();759(function() {760 var deferred1 = Promise.defer()761 var p1 = deferred1.promise762 var deferred2 = Promise.defer()763 var p2 = deferred2.promise764 var deferred3 = Promise.defer()765 var p3 = deferred3.promise766 Promise.race([p1, p2, p3]).chain(767 function(x) { assertAsync(x === 3, "one/resolve") },768 assertUnreachable769 )770 deferred3.resolve(3)771 deferred1.resolve(1)772 assertAsyncRan()773})();774(function() {775 var deferred = Promise.defer()776 var p1 = deferred.promise777 var p2 = Promise.accept(2)778 var p3 = Promise.defer().promise779 Promise.race([p1, p2, p3]).chain(780 function(x) { assertAsync(x === 2, "resolved/one") },781 assertUnreachable782 )783 deferred.resolve(1)784 assertAsyncRan()785})();786(function() {787 var deferred1 = Promise.defer()788 var p1 = deferred1.promise789 var deferred2 = Promise.defer()790 var p2 = deferred2.promise791 var deferred3 = Promise.defer()792 var p3 = deferred3.promise793 Promise.race([p1, p2, p3]).chain(794 function(x) { assertAsync(x === 3, "one/resolve/reject") },795 assertUnreachable796 )797 deferred3.resolve(3)798 deferred1.reject(1)799 assertAsyncRan()800})();801(function() {802 var deferred1 = Promise.defer()803 var p1 = deferred1.promise804 var deferred2 = Promise.defer()805 var p2 = deferred2.promise806 var deferred3 = Promise.defer()807 var p3 = deferred3.promise808 Promise.race([p1, p2, p3]).chain(809 assertUnreachable,810 function(x) { assertAsync(x === 3, "one/reject/resolve") }811 )812 deferred3.reject(3)813 deferred1.resolve(1)814 assertAsyncRan()815})();816(function() {817 function testPromiseRaceNonIterable(value) {818 Promise.race(value).chain(819 assertUnreachable,820 function(r) {821 assertAsync(r instanceof TypeError, 'race/non iterable');822 });823 assertAsyncRan();824 }825 testPromiseRaceNonIterable(null);826 testPromiseRaceNonIterable(undefined);827 testPromiseRaceNonIterable({});828 testPromiseRaceNonIterable(42);829})();830(function() {831 var deferred1 = Promise.defer()832 var p1 = deferred1.promise833 var deferred2 = Promise.defer()834 var p2 = deferred2.promise835 var deferred3 = Promise.defer()836 var p3 = deferred3.promise837 function* f() {838 yield p1;839 yield p2;840 yield p3;841 }842 Promise.race(f()).chain(843 function(x) { assertAsync(x === 3, "race/iterable/resolve/reject") },844 assertUnreachable845 )846 deferred3.resolve(3)847 deferred1.reject(1)848 assertAsyncRan()849})();850(function() {851 var deferred1 = Promise.defer()852 var p1 = deferred1.promise853 var deferred2 = Promise.defer()854 var p2 = deferred2.promise855 var deferred3 = Promise.defer()856 var p3 = deferred3.promise857 function* f() {858 yield p1;859 yield p2;860 yield p3;861 }862 Promise.race(f()).chain(863 assertUnreachable,864 function(x) { assertAsync(x === 3, "race/iterable/reject/resolve") }865 )866 deferred3.reject(3)867 deferred1.resolve(1)868 assertAsyncRan()869})();870(function() {871 'use strict';872 var getCalls = 0;873 var funcCalls = 0;874 var nextCalls = 0;875 defineProperty(numberPrototype, symbolIterator, {876 get: function() {877 assertEquals('number', typeof this);878 getCalls++;879 return function() {880 assertEquals('number', typeof this);881 funcCalls++;882 var n = this;883 var i = 0884 return {885 next() {886 nextCalls++;887 return {value: i++, done: i > n};888 }889 };890 };891 },892 configurable: true893 });894 Promise.race(3).chain(895 function(x) {896 assertAsync(x === 0, "race/iterable/number");897 },898 assertUnreachable);899 delete numberPrototype[symbolIterator];900 assertEquals(getCalls, 1);901 assertEquals(funcCalls, 1);902 assertEquals(nextCalls, 3 + 1); // + 1 for {done: true}903 assertAsyncRan();904})();905(function() {906 var log907 function MyPromise(resolver) {908 log += "n"909 var promise = new Promise(function(resolve, reject) {910 resolver(911 function(x) { log += "x" + x; resolve(x) },912 function(r) { log += "r" + r; reject(r) }913 )914 })915 promise.__proto__ = MyPromise.prototype916 return promise917 }918 MyPromise.__proto__ = Promise919 MyPromise.defer = function() {920 log += "d"921 return call(this.__proto__.defer, this)922 }923 MyPromise.prototype.__proto__ = Promise.prototype924 MyPromise.prototype.chain = function(resolve, reject) {925 log += "c"926 return call(this.__proto__.__proto__.chain, this, resolve, reject)927 }928 log = ""929 var p1 = new MyPromise(function(resolve, reject) { resolve(1) })930 var p2 = new MyPromise(function(resolve, reject) { reject(2) })931 var d3 = MyPromise.defer()932 assertTrue(d3.promise instanceof Promise, "subclass/instance")933 assertTrue(d3.promise instanceof MyPromise, "subclass/instance-my3")934 assertTrue(log === "nx1nr2dn", "subclass/create")935 log = ""936 var p4 = MyPromise.resolve(4)937 var p5 = MyPromise.reject(5)938 assertTrue(p4 instanceof MyPromise, "subclass/instance4")939 assertTrue(p4 instanceof MyPromise, "subclass/instance-my4")940 assertTrue(p5 instanceof MyPromise, "subclass/instance5")941 assertTrue(p5 instanceof MyPromise, "subclass/instance-my5")942 d3.resolve(3)943 assertTrue(log === "nx4nr5x3", "subclass/resolve")944 log = ""945 var d6 = MyPromise.defer()946 d6.promise.chain(function(x) {947 return new Promise(function(resolve) { resolve(x) })948 }).chain(function() {})949 d6.resolve(6)950 assertTrue(log === "dncncnx6", "subclass/chain")951 log = ""952 Promise.all([11, Promise.accept(12), 13, MyPromise.accept(14), 15, 16])953 assertTrue(log === "nx14", "subclass/all/arg")954 log = ""955 MyPromise.all([21, Promise.accept(22), 23, MyPromise.accept(24), 25, 26])956 assertTrue(log === "nx24nnx21nnx[object Promise]nnx23nnnx25nnx26n",957 "subclass/all/self")958})();959(function() {960 'use strict';961 class Pact extends Promise { }962 class Vow extends Pact { }963 class Oath extends Vow { }964 Oath.constructor = Vow;965 assertTrue(Pact.resolve(Pact.resolve()).constructor === Pact,966 "subclass/resolve/own");967 assertTrue(Pact.resolve(Promise.resolve()).constructor === Pact,968 "subclass/resolve/ancestor");969 assertTrue(Pact.resolve(Vow.resolve()).constructor === Pact,970 "subclass/resolve/descendant"); var vow = Vow.resolve();971 vow.constructor = Oath;972 assertTrue(Oath.resolve(vow) === vow,973 "subclass/resolve/descendant with transplanted own constructor");974}());975(function() {976 var thenCalled = false;977 var resolve;978 var promise = new Promise(function(res) { resolve = res; });979 resolve({ then() { thenCalled = true; throw new Error(); } });980 assertLater(function() { return thenCalled; }, "resolve-with-thenable");981});982(function() {983 var calledWith;984 var resolve;985 var p1 = (new Promise(function(res) { resolve = res; }));986 var p2 = p1.then(function(v) {987 return {988 then(resolve, reject) { resolve({ then() { calledWith = v }}); }989 };990 });991 resolve({ then(resolve) { resolve(2); } });992 assertLater(function() { return calledWith === 2; },993 "resolve-with-thenable2");994})();995(function() {996 var p = Promise.resolve();997 var callCount = 0;998 defineProperty(p, "constructor", {999 get: function() { ++callCount; return Promise; }1000 });1001 p.then();1002 assertEquals(1, callCount);1003})();...

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Deferred.js

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1/*2 Ext.Deferred adapted from:3 [DeftJS](https://github.com/deftjs/deftjs5)4 Copyright (c) 2012-2013 [DeftJS Framework Contributors](http://deftjs.org)5 Open source under the [MIT License](http://en.wikipedia.org/wiki/MIT_License).6 when(), all(), any(), some(), map(), reduce(), delay() and timeout()7 sequence(), parallel(), pipeline()8 methods adapted from: [when.js](https://github.com/cujojs/when)9 Copyright (c) B Cavalier & J Hann10 Open source under the [MIT License](http://en.wikipedia.org/wiki/MIT_License).11 */12/**13 * Deferreds are the mechanism used to create new Promises. A Deferred has a single14 * associated Promise that can be safely returned to external consumers to ensure they do15 * not interfere with the resolution or rejection of the deferred operation.16 *17 * This implementation of Promises is an extension of the ECMAScript 6 Promises API as18 * detailed [here][1]. For a compatible, though less full featured, API see `{@link Ext.Promise}`.19 *20 * A Deferred is typically used within the body of a function that performs an asynchronous21 * operation. When that operation succeeds, the Deferred should be resolved; if that22 * operation fails, the Deferred should be rejected.23 *24 * Each Deferred has an associated Promise. A Promise delegates `then` calls to its25 * Deferred's `then` method. In this way, access to Deferred operations are divided between26 * producer (Deferred) and consumer (Promise) roles.27 *28 * ## Basic Usage29 *30 * In it's most common form, a method will create and return a Promise like this:31 *32 * // A method in a service class which uses a Store and returns a Promise33 * //34 * loadCompanies: function () {35 * var deferred = new Ext.Deferred(); // create the Ext.Deferred object36 *37 * this.companyStore.load({38 * callback: function (records, operation, success) {39 * if (success) {40 * // Use "deferred" to drive the promise:41 * deferred.resolve(records);42 * }43 * else {44 * // Use "deferred" to drive the promise:45 * deferred.reject("Error loading Companies.");46 * }47 * }48 * });49 *50 * return deferred.promise; // return the Promise to the caller51 * }52 *53 * You can see this method first creates a `{@link Ext.Deferred Deferred}` object. It then54 * returns its `Promise` object for use by the caller. Finally, in the asynchronous55 * callback, it resolves the `deferred` object if the call was successful, and rejects the56 * `deferred` if the call failed.57 *58 * When a Deferred's `resolve` method is called, it fulfills with the optionally specified59 * value. If `resolve` is called with a then-able (i.e.a Function or Object with a `then`60 * function, such as another Promise) it assimilates the then-able's result; the Deferred61 * provides its own `resolve` and `reject` methods as the onFulfilled or onRejected62 * arguments in a call to that then-able's `then` function. If an error is thrown while63 * calling the then-able's `then` function (prior to any call back to the specified64 * `resolve` or `reject` methods), the Deferred rejects with that error. If a Deferred's65 * `resolve` method is called with its own Promise, it rejects with a TypeError.66 *67 * When a Deferred's `reject` method is called, it rejects with the optionally specified68 * reason.69 *70 * Each time a Deferred's `then` method is called, it captures a pair of optional71 * onFulfilled and onRejected callbacks and returns a Promise of the Deferred's future72 * value as transformed by those callbacks.73 *74 * See `{@link Ext.promise.Promise}` for an example of using the returned Promise.75 *76 * @since 6.0.077 */78Ext.define('Ext.Deferred', function (Deferred) {79 var ExtPromise,80 when;81return {82 extend: 'Ext.promise.Deferred',83 requires: [84 'Ext.Promise'85 ],86 statics: {87 _ready: function () {88 // Our requires are met, so we can cache Ext.promise.Deferred89 ExtPromise = Ext.promise.Promise;90 when = Ext.Promise.resolve;91 },92 /**93 * Returns a new Promise that will only resolve once all the specified94 * `promisesOrValues` have resolved.95 *96 * The resolution value will be an Array containing the resolution value of each97 * of the `promisesOrValues`.98 *99 * @param {Mixed[]/Ext.promise.Promise[]/Ext.promise.Promise} promisesOrValues An100 * Array of values or Promises, or a Promise of an Array of values or Promises.101 * @return {Ext.promise.Promise} A Promise of an Array of the resolved values.102 * @static103 */104 all: function () {105 return ExtPromise.all.apply(ExtPromise, arguments);106 },107 /**108 * Initiates a competitive race, returning a new Promise that will resolve when109 * any one of the specified `promisesOrValues` have resolved, or will reject when110 * all `promisesOrValues` have rejected or cancelled.111 *112 * The resolution value will the first value of `promisesOrValues` to resolve.113 *114 * @param {Mixed[]/Ext.promise.Promise[]/Ext.promise.Promise} promisesOrValues An115 * Array of values or Promises, or a Promise of an Array of values or Promises.116 * @return {Ext.promise.Promise} A Promise of the first resolved value.117 * @static118 */119 any: function (promisesOrValues) {120 //<debug>121 if (!(Ext.isArray(promisesOrValues) || ExtPromise.is(promisesOrValues))) {122 Ext.raise('Invalid parameter: expected an Array or Promise of an Array.');123 }124 //</debug>125 return Deferred.some(promisesOrValues, 1).then(function (array) {126 return array[0];127 }, function (error) {128 if (error instanceof Error &&129 error.message === 'Too few Promises were resolved.') {130 Ext.raise('No Promises were resolved.');131 }132 else {133 throw error;134 }135 });136 },137 /**138 * Returns a new Promise that will automatically resolve with the specified139 * Promise or value after the specified delay (in milliseconds).140 *141 * @param {Mixed} promiseOrValue A Promise or value.142 * @param {Number} milliseconds A delay duration (in milliseconds).143 * @return {Ext.promise.Promise} A Promise of the specified Promise or value that144 * will resolve after the specified delay.145 * @static146 */147 delay: function (promiseOrValue, milliseconds) {148 var deferred;149 if (arguments.length === 1) {150 milliseconds = promiseOrValue;151 promiseOrValue = undefined;152 }153 milliseconds = Math.max(milliseconds, 0);154 deferred = new Deferred();155 setTimeout(function () {156 deferred.resolve(promiseOrValue);157 }, milliseconds);158 return deferred.promise;159 },160 /**161 * Traditional map function, similar to `Array.prototype.map()`, that allows162 * input to contain promises and/or values.163 *164 * The specified map function may return either a value or a promise.165 *166 * @param {Mixed[]/Ext.promise.Promise[]/Ext.promise.Promise} promisesOrValues An167 * Array of values or Promises, or a Promise of an Array of values or Promises.168 * @param {Function} mapFn A Function to call to transform each resolved value in169 * the Array.170 * @return {Ext.promise.Promise} A Promise of an Array of the mapped resolved171 * values.172 * @static173 */174 map: function (promisesOrValues, mapFn) {175 //<debug>176 if (!(Ext.isArray(promisesOrValues) || ExtPromise.is(promisesOrValues))) {177 Ext.raise('Invalid parameter: expected an Array or Promise of an Array.');178 }179 if (!Ext.isFunction(mapFn)) {180 Ext.raise('Invalid parameter: expected a function.');181 }182 //</debug>183 return Deferred.resolved(promisesOrValues).then(function (promisesOrValues) {184 var deferred, index, promiseOrValue, remainingToResolve, resolve, results, i, len;185 remainingToResolve = promisesOrValues.length;186 results = new Array(promisesOrValues.length);187 deferred = new Deferred();188 if (!remainingToResolve) {189 deferred.resolve(results);190 }191 else {192 resolve = function (item, index) {193 return Deferred.resolved(item).then(function (value) {194 return mapFn(value, index, results);195 }).then(function (value) {196 results[index] = value;197 if (!--remainingToResolve) {198 deferred.resolve(results);199 }200 return value;201 }, function (reason) {202 return deferred.reject(reason);203 });204 };205 for (index = i = 0, len = promisesOrValues.length; i < len; index = ++i) {206 promiseOrValue = promisesOrValues[index];207 if (index in promisesOrValues) {208 resolve(promiseOrValue, index);209 }210 else {211 remainingToResolve--;212 }213 }214 }215 return deferred.promise;216 });217 },218 /**219 * Returns a new function that wraps the specified function and caches the220 * results for previously processed inputs.221 *222 * Similar to {@link Ext.Function#memoize Ext.Function.memoize()}, except it223 * allows for parameters that are Promises and/or values.224 *225 * @param {Function} fn A Function to wrap.226 * @param {Object} scope An optional scope in which to execute the wrapped function.227 * @param {Function} hashFn An optional function used to compute a hash key for228 * storing the result, based on the arguments to the original function.229 * @return {Function} The new wrapper function.230 * @static231 */232 memoize: function (fn, scope, hashFn) {233 var memoizedFn = Ext.Function.memoize(fn, scope, hashFn);234 return function () {235 return Deferred.all(Ext.Array.slice(arguments)).then(function (values) {236 return memoizedFn.apply(scope, values);237 });238 };239 },240 /**241 * Execute an Array (or {@link Ext.promise.Promise Promise} of an Array) of242 * functions in parallel.243 *244 * The specified functions may optionally return their results as245 * {@link Ext.promise.Promise Promises}.246 *247 * @param {Function[]/Ext.promise.Promise} fns The Array (or Promise of an Array)248 * of functions to execute.249 * @param {Object} scope Optional scope in which to execute the specified functions.250 * @return {Ext.promise.Promise} Promise of an Array of results for each function251 * call (in the same order).252 * @static253 */254 parallel: function (fns, scope) {255 if (scope == null) {256 scope = null;257 }258 var args = Ext.Array.slice(arguments, 2);259 return Deferred.map(fns, function (fn) {260 if (!Ext.isFunction(fn)) {261 throw new Error('Invalid parameter: expected a function.');262 }263 return fn.apply(scope, args);264 });265 },266 /**267 * Execute an Array (or {@link Ext.promise.Promise Promise} of an Array) of268 * functions as a pipeline, where each function's result is passed to the269 * subsequent function as input.270 *271 * The specified functions may optionally return their results as272 * {@link Ext.promise.Promise Promises}.273 *274 * @param {Function[]/Ext.promise.Promise} fns The Array (or Promise of an Array)275 * of functions to execute.276 * @param {Object} initialValue Initial value to be passed to the first function277 * in the pipeline.278 * @param {Object} scope Optional scope in which to execute the specified functions.279 * @return {Ext.promise.Promise} Promise of the result value for the final280 * function in the pipeline.281 * @static282 */283 pipeline: function (fns, initialValue, scope) {284 if (scope == null) {285 scope = null;286 }287 return Deferred.reduce(fns, function (value, fn) {288 if (!Ext.isFunction(fn)) {289 throw new Error('Invalid parameter: expected a function.');290 }291 return fn.call(scope, value);292 }, initialValue);293 },294 /**295 * Traditional reduce function, similar to `Array.reduce()`, that allows input to296 * contain promises and/or values.297 *298 * @param {Mixed[]/Ext.promise.Promise[]/Ext.promise.Promise} values An299 * Array of values or Promises, or a Promise of an Array of values or Promises.300 * @param {Function} reduceFn A Function to call to transform each successive301 * item in the Array into the final reduced value.302 * @param {Mixed} initialValue An initial Promise or value.303 * @return {Ext.promise.Promise} A Promise of the reduced value.304 * @static305 */306 reduce: function (values, reduceFn, initialValue) {307 //<debug>308 if (!(Ext.isArray(values) || ExtPromise.is(values))) {309 Ext.raise('Invalid parameter: expected an Array or Promise of an Array.');310 }311 if (!Ext.isFunction(reduceFn)) {312 Ext.raise('Invalid parameter: expected a function.');313 }314 //</debug>315 var initialValueSpecified = arguments.length === 3;316 return Deferred.resolved(values).then(function (promisesOrValues) {317 var reduceArguments = [318 promisesOrValues,319 function (previousValueOrPromise, currentValueOrPromise, currentIndex) {320 return Deferred.resolved(previousValueOrPromise).then(function (previousValue) {321 return Deferred.resolved(currentValueOrPromise).then(function (currentValue) {322 return reduceFn(previousValue, currentValue, currentIndex, promisesOrValues);323 });324 });325 }326 ];327 if (initialValueSpecified) {328 reduceArguments.push(initialValue);329 }330 return Ext.Array.reduce.apply(Ext.Array, reduceArguments);331 });332 },333 /**334 * Convenience method that returns a new Promise rejected with the specified335 * reason.336 *337 * @param {Error} reason Rejection reason.338 * @return {Ext.promise.Promise} The rejected Promise.339 * @static340 */341 rejected: function (reason) {342 var deferred = new Ext.Deferred();343 deferred.reject(reason);344 return deferred.promise;345 },346 /**347 * Returns a new Promise that either348 *349 * * Resolves immediately for the specified value, or350 * * Resolves or rejects when the specified promise (or third-party Promise or351 * then()-able) is resolved or rejected.352 *353 * @param {Mixed} promiseOrValue A Promise (or third-party Promise or then()-able)354 * or value.355 * @return {Ext.promise.Promise} A Promise of the specified Promise or value.356 * @static357 */358 resolved: function (value) {359 var deferred = new Ext.Deferred();360 deferred.resolve(value);361 return deferred.promise;362 },363 /**364 * Execute an Array (or {@link Ext.promise.Promise Promise} of an Array) of365 * functions sequentially.366 *367 * The specified functions may optionally return their results as {@link368 * Ext.promise.Promise Promises}.369 *370 * @param {Function[]/Ext.promise.Promise} fns The Array (or Promise of an Array)371 * of functions to execute.372 * @param {Object} scope Optional scope in which to execute the specified functions.373 * @return {Ext.promise.Promise} Promise of an Array of results for each function374 * call (in the same order).375 * @static376 */377 sequence: function (fns, scope) {378 if (scope == null) {379 scope = null;380 }381 var args = Ext.Array.slice(arguments, 2);382 return Deferred.reduce(fns, function (results, fn) {383 if (!Ext.isFunction(fn)) {384 throw new Error('Invalid parameter: expected a function.');385 }386 return Deferred.resolved(fn.apply(scope, args)).then(function (result) {387 results.push(result);388 return results;389 });390 }, []);391 },392 /**393 * Initiates a competitive race, returning a new Promise that will resolve when394 * `howMany` of the specified `promisesOrValues` have resolved, or will reject395 * when it becomes impossible for `howMany` to resolve.396 *397 * The resolution value will be an Array of the first `howMany` values of398 * `promisesOrValues` to resolve.399 *400 * @param {Mixed[]/Ext.promise.Promise[]/Ext.promise.Promise} promisesOrValues An401 * Array of values or Promises, or a Promise of an Array of values or Promises.402 * @param {Number} howMany The expected number of resolved values.403 * @return {Ext.promise.Promise} A Promise of the expected number of resolved404 * values.405 * @static406 */407 some: function (promisesOrValues, howMany) {408 //<debug>409 if (!(Ext.isArray(promisesOrValues) || ExtPromise.is(promisesOrValues))) {410 Ext.raise('Invalid parameter: expected an Array or Promise of an Array.');411 }412 if (!Ext.isNumeric(howMany) || howMany <= 0) {413 Ext.raise('Invalid parameter: expected a positive integer.');414 }415 //</debug>416 return Deferred.resolved(promisesOrValues).then(function (promisesOrValues) {417 var deferred, index, onReject, onResolve, promiseOrValue,418 remainingToReject, remainingToResolve, values, i, len;419 values = [];420 remainingToResolve = howMany;421 remainingToReject = (promisesOrValues.length - remainingToResolve) + 1;422 deferred = new Deferred();423 if (promisesOrValues.length < howMany) {424 deferred.reject(new Error('Too few Promises were resolved.'));425 }426 else {427 onResolve = function (value) {428 if (remainingToResolve > 0) {429 values.push(value);430 }431 remainingToResolve--;432 if (remainingToResolve === 0) {433 deferred.resolve(values);434 }435 return value;436 };437 onReject = function (reason) {438 remainingToReject--;439 if (remainingToReject === 0) {440 deferred.reject(new Error('Too few Promises were resolved.'));441 }442 return reason;443 };444 for (index = i = 0, len = promisesOrValues.length; i < len; index = ++i) {445 promiseOrValue = promisesOrValues[index];446 if (index in promisesOrValues) {447 Deferred.resolved(promiseOrValue).then(onResolve, onReject);448 }449 }450 }451 return deferred.promise;452 });453 },454 /**455 * Returns a new Promise that will automatically reject after the specified456 * timeout (in milliseconds) if the specified promise has not resolved or457 * rejected.458 *459 * @param {Mixed} promiseOrValue A Promise or value.460 * @param {Number} milliseconds A timeout duration (in milliseconds).461 * @return {Ext.promise.Promise} A Promise of the specified Promise or value that462 * enforces the specified timeout.463 * @static464 */465 timeout: function (promiseOrValue, milliseconds) {466 var deferred = new Deferred(),467 timeoutId;468 timeoutId = setTimeout(function () {469 if (timeoutId) {470 deferred.reject(new Error('Promise timed out.'));471 }472 }, milliseconds);473 Deferred.resolved(promiseOrValue).then(function (value) {474 clearTimeout(timeoutId);475 timeoutId = null;476 deferred.resolve(value);477 }, function (reason) {478 clearTimeout(timeoutId);479 timeoutId = null;480 deferred.reject(reason);481 });482 return deferred.promise;483 }484 }485}},486function (Deferred) {487 Deferred._ready();...

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when.js

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1/**2 @license3 when.js - https://github.com/cujojs/when4 MIT License (c) copyright B Cavalier & J Hann5 * A lightweight CommonJS Promises/A and when() implementation6 * when is part of the cujo.js family of libraries (http://cujojs.com/)7 *8 * Licensed under the MIT License at:9 * http://www.opensource.org/licenses/mit-license.php10 *11 * @version 1.7.112 */13(function(define) { 'use strict';14define(function () {15 var reduceArray, slice, undef;16 //17 // Public API18 //19 when.defer = defer; // Create a deferred20 when.resolve = resolve; // Create a resolved promise21 when.reject = reject; // Create a rejected promise22 when.join = join; // Join 2 or more promises23 when.all = all; // Resolve a list of promises24 when.map = map; // Array.map() for promises25 when.reduce = reduce; // Array.reduce() for promises26 when.any = any; // One-winner race27 when.some = some; // Multi-winner race28 when.chain = chain; // Make a promise trigger another resolver29 when.isPromise = isPromise; // Determine if a thing is a promise30 /**31 * Register an observer for a promise or immediate value.32 *33 * @param {*} promiseOrValue34 * @param {function?} [onFulfilled] callback to be called when promiseOrValue is35 * successfully fulfilled. If promiseOrValue is an immediate value, callback36 * will be invoked immediately.37 * @param {function?} [onRejected] callback to be called when promiseOrValue is38 * rejected.39 * @param {function?} [onProgress] callback to be called when progress updates40 * are issued for promiseOrValue.41 * @returns {Promise} a new {@link Promise} that will complete with the return42 * value of callback or errback or the completion value of promiseOrValue if43 * callback and/or errback is not supplied.44 */45 function when(promiseOrValue, onFulfilled, onRejected, onProgress) {46 // Get a trusted promise for the input promiseOrValue, and then47 // register promise handlers48 return resolve(promiseOrValue).then(onFulfilled, onRejected, onProgress);49 }50 /**51 * Returns promiseOrValue if promiseOrValue is a {@link Promise}, a new Promise if52 * promiseOrValue is a foreign promise, or a new, already-fulfilled {@link Promise}53 * whose value is promiseOrValue if promiseOrValue is an immediate value.54 *55 * @param {*} promiseOrValue56 * @returns Guaranteed to return a trusted Promise. If promiseOrValue is a when.js {@link Promise}57 * returns promiseOrValue, otherwise, returns a new, already-resolved, when.js {@link Promise}58 * whose resolution value is:59 * * the resolution value of promiseOrValue if it's a foreign promise, or60 * * promiseOrValue if it's a value61 */62 function resolve(promiseOrValue) {63 var promise, deferred;64 if(promiseOrValue instanceof Promise) {65 // It's a when.js promise, so we trust it66 promise = promiseOrValue;67 } else {68 // It's not a when.js promise. See if it's a foreign promise or a value.69 if(isPromise(promiseOrValue)) {70 // It's a thenable, but we don't know where it came from, so don't trust71 // its implementation entirely. Introduce a trusted middleman when.js promise72 deferred = defer();73 // IMPORTANT: This is the only place when.js should ever call .then() on an74 // untrusted promise. Don't expose the return value to the untrusted promise75 promiseOrValue.then(76 function(value) { deferred.resolve(value); },77 function(reason) { deferred.reject(reason); },78 function(update) { deferred.progress(update); }79 );80 promise = deferred.promise;81 } else {82 // It's a value, not a promise. Create a resolved promise for it.83 promise = fulfilled(promiseOrValue);84 }85 }86 return promise;87 }88 /**89 * Returns a rejected promise for the supplied promiseOrValue. The returned90 * promise will be rejected with:91 * - promiseOrValue, if it is a value, or92 * - if promiseOrValue is a promise93 * - promiseOrValue's value after it is fulfilled94 * - promiseOrValue's reason after it is rejected95 * @param {*} promiseOrValue the rejected value of the returned {@link Promise}96 * @returns {Promise} rejected {@link Promise}97 */98 function reject(promiseOrValue) {99 return when(promiseOrValue, rejected);100 }101 /**102 * Trusted Promise constructor. A Promise created from this constructor is103 * a trusted when.js promise. Any other duck-typed promise is considered104 * untrusted.105 * @constructor106 * @name Promise107 */108 function Promise(then) {109 this.then = then;110 }111 Promise.prototype = {112 /**113 * Register a callback that will be called when a promise is114 * fulfilled or rejected. Optionally also register a progress handler.115 * Shortcut for .then(onFulfilledOrRejected, onFulfilledOrRejected, onProgress)116 * @param {function?} [onFulfilledOrRejected]117 * @param {function?} [onProgress]118 * @returns {Promise}119 */120 always: function(onFulfilledOrRejected, onProgress) {121 return this.then(onFulfilledOrRejected, onFulfilledOrRejected, onProgress);122 },123 /**124 * Register a rejection handler. Shortcut for .then(undefined, onRejected)125 * @param {function?} onRejected126 * @returns {Promise}127 */128 otherwise: function(onRejected) {129 return this.then(undef, onRejected);130 },131 /**132 * Shortcut for .then(function() { return value; })133 * @param {*} value134 * @returns {Promise} a promise that:135 * - is fulfilled if value is not a promise, or136 * - if value is a promise, will fulfill with its value, or reject137 * with its reason.138 */139 yield: function(value) {140 return this.then(function() {141 return value;142 });143 },144 /**145 * Assumes that this promise will fulfill with an array, and arranges146 * for the onFulfilled to be called with the array as its argument list147 * i.e. onFulfilled.spread(undefined, array).148 * @param {function} onFulfilled function to receive spread arguments149 * @returns {Promise}150 */151 spread: function(onFulfilled) {152 return this.then(function(array) {153 // array may contain promises, so resolve its contents.154 return all(array, function(array) {155 return onFulfilled.apply(undef, array);156 });157 });158 }159 };160 /**161 * Create an already-resolved promise for the supplied value162 * @private163 *164 * @param {*} value165 * @returns {Promise} fulfilled promise166 */167 function fulfilled(value) {168 var p = new Promise(function(onFulfilled) {169 // TODO: Promises/A+ check typeof onFulfilled170 try {171 return resolve(onFulfilled ? onFulfilled(value) : value);172 } catch(e) {173 return rejected(e);174 }175 });176 return p;177 }178 /**179 * Create an already-rejected {@link Promise} with the supplied180 * rejection reason.181 * @private182 *183 * @param {*} reason184 * @returns {Promise} rejected promise185 */186 function rejected(reason) {187 var p = new Promise(function(_, onRejected) {188 // TODO: Promises/A+ check typeof onRejected189 try {190 return onRejected ? resolve(onRejected(reason)) : rejected(reason);191 } catch(e) {192 return rejected(e);193 }194 });195 return p;196 }197 /**198 * Creates a new, Deferred with fully isolated resolver and promise parts,199 * either or both of which may be given out safely to consumers.200 * The Deferred itself has the full API: resolve, reject, progress, and201 * then. The resolver has resolve, reject, and progress. The promise202 * only has then.203 *204 * @returns {Deferred}205 */206 function defer() {207 var deferred, promise, handlers, progressHandlers,208 _then, _progress, _resolve;209 /**210 * The promise for the new deferred211 * @type {Promise}212 */213 promise = new Promise(then);214 /**215 * The full Deferred object, with {@link Promise} and {@link Resolver} parts216 * @class Deferred217 * @name Deferred218 */219 deferred = {220 then: then, // DEPRECATED: use deferred.promise.then221 resolve: promiseResolve,222 reject: promiseReject,223 // TODO: Consider renaming progress() to notify()224 progress: promiseProgress,225 promise: promise,226 resolver: {227 resolve: promiseResolve,228 reject: promiseReject,229 progress: promiseProgress230 }231 };232 handlers = [];233 progressHandlers = [];234 /**235 * Pre-resolution then() that adds the supplied callback, errback, and progback236 * functions to the registered listeners237 * @private238 *239 * @param {function?} [onFulfilled] resolution handler240 * @param {function?} [onRejected] rejection handler241 * @param {function?} [onProgress] progress handler242 */243 _then = function(onFulfilled, onRejected, onProgress) {244 // TODO: Promises/A+ check typeof onFulfilled, onRejected, onProgress245 var deferred, progressHandler;246 deferred = defer();247 progressHandler = typeof onProgress === 'function'248 ? function(update) {249 try {250 // Allow progress handler to transform progress event251 deferred.progress(onProgress(update));252 } catch(e) {253 // Use caught value as progress254 deferred.progress(e);255 }256 }257 : function(update) { deferred.progress(update); };258 handlers.push(function(promise) {259 promise.then(onFulfilled, onRejected)260 .then(deferred.resolve, deferred.reject, progressHandler);261 });262 progressHandlers.push(progressHandler);263 return deferred.promise;264 };265 /**266 * Issue a progress event, notifying all progress listeners267 * @private268 * @param {*} update progress event payload to pass to all listeners269 */270 _progress = function(update) {271 processQueue(progressHandlers, update);272 return update;273 };274 /**275 * Transition from pre-resolution state to post-resolution state, notifying276 * all listeners of the resolution or rejection277 * @private278 * @param {*} value the value of this deferred279 */280 _resolve = function(value) {281 value = resolve(value);282 // Replace _then with one that directly notifies with the result.283 _then = value.then;284 // Replace _resolve so that this Deferred can only be resolved once285 _resolve = resolve;286 // Make _progress a noop, to disallow progress for the resolved promise.287 _progress = noop;288 // Notify handlers289 processQueue(handlers, value);290 // Free progressHandlers array since we'll never issue progress events291 progressHandlers = handlers = undef;292 return value;293 };294 return deferred;295 /**296 * Wrapper to allow _then to be replaced safely297 * @param {function?} [onFulfilled] resolution handler298 * @param {function?} [onRejected] rejection handler299 * @param {function?} [onProgress] progress handler300 * @returns {Promise} new promise301 */302 function then(onFulfilled, onRejected, onProgress) {303 // TODO: Promises/A+ check typeof onFulfilled, onRejected, onProgress304 return _then(onFulfilled, onRejected, onProgress);305 }306 /**307 * Wrapper to allow _resolve to be replaced308 */309 function promiseResolve(val) {310 return _resolve(val);311 }312 /**313 * Wrapper to allow _reject to be replaced314 */315 function promiseReject(err) {316 return _resolve(rejected(err));317 }318 /**319 * Wrapper to allow _progress to be replaced320 */321 function promiseProgress(update) {322 return _progress(update);323 }324 }325 /**326 * Determines if promiseOrValue is a promise or not. Uses the feature327 * test from http://wiki.commonjs.org/wiki/Promises/A to determine if328 * promiseOrValue is a promise.329 *330 * @param {*} promiseOrValue anything331 * @returns {boolean} true if promiseOrValue is a {@link Promise}332 */333 function isPromise(promiseOrValue) {334 return promiseOrValue && typeof promiseOrValue.then === 'function';335 }336 /**337 * Initiates a competitive race, returning a promise that will resolve when338 * howMany of the supplied promisesOrValues have resolved, or will reject when339 * it becomes impossible for howMany to resolve, for example, when340 * (promisesOrValues.length - howMany) + 1 input promises reject.341 *342 * @param {Array} promisesOrValues array of anything, may contain a mix343 * of promises and values344 * @param howMany {number} number of promisesOrValues to resolve345 * @param {function?} [onFulfilled] resolution handler346 * @param {function?} [onRejected] rejection handler347 * @param {function?} [onProgress] progress handler348 * @returns {Promise} promise that will resolve to an array of howMany values that349 * resolved first, or will reject with an array of (promisesOrValues.length - howMany) + 1350 * rejection reasons.351 */352 function some(promisesOrValues, howMany, onFulfilled, onRejected, onProgress) {353 checkCallbacks(2, arguments);354 return when(promisesOrValues, function(promisesOrValues) {355 var toResolve, toReject, values, reasons, deferred, fulfillOne, rejectOne, progress, len, i;356 len = promisesOrValues.length >>> 0;357 toResolve = Math.max(0, Math.min(howMany, len));358 values = [];359 toReject = (len - toResolve) + 1;360 reasons = [];361 deferred = defer();362 // No items in the input, resolve immediately363 if (!toResolve) {364 deferred.resolve(values);365 } else {366 progress = deferred.progress;367 rejectOne = function(reason) {368 reasons.push(reason);369 if(!--toReject) {370 fulfillOne = rejectOne = noop;371 deferred.reject(reasons);372 }373 };374 fulfillOne = function(val) {375 // This orders the values based on promise resolution order376 // Another strategy would be to use the original position of377 // the corresponding promise.378 values.push(val);379 if (!--toResolve) {380 fulfillOne = rejectOne = noop;381 deferred.resolve(values);382 }383 };384 for(i = 0; i < len; ++i) {385 if(i in promisesOrValues) {386 when(promisesOrValues[i], fulfiller, rejecter, progress);387 }388 }389 }390 return deferred.then(onFulfilled, onRejected, onProgress);391 function rejecter(reason) {392 rejectOne(reason);393 }394 function fulfiller(val) {395 fulfillOne(val);396 }397 });398 }399 /**400 * Initiates a competitive race, returning a promise that will resolve when401 * any one of the supplied promisesOrValues has resolved or will reject when402 * *all* promisesOrValues have rejected.403 *404 * @param {Array|Promise} promisesOrValues array of anything, may contain a mix405 * of {@link Promise}s and values406 * @param {function?} [onFulfilled] resolution handler407 * @param {function?} [onRejected] rejection handler408 * @param {function?} [onProgress] progress handler409 * @returns {Promise} promise that will resolve to the value that resolved first, or410 * will reject with an array of all rejected inputs.411 */412 function any(promisesOrValues, onFulfilled, onRejected, onProgress) {413 function unwrapSingleResult(val) {414 return onFulfilled ? onFulfilled(val[0]) : val[0];415 }416 return some(promisesOrValues, 1, unwrapSingleResult, onRejected, onProgress);417 }418 /**419 * Return a promise that will resolve only once all the supplied promisesOrValues420 * have resolved. The resolution value of the returned promise will be an array421 * containing the resolution values of each of the promisesOrValues.422 * @memberOf when423 *424 * @param {Array|Promise} promisesOrValues array of anything, may contain a mix425 * of {@link Promise}s and values426 * @param {function?} [onFulfilled] resolution handler427 * @param {function?} [onRejected] rejection handler428 * @param {function?} [onProgress] progress handler429 * @returns {Promise}430 */431 function all(promisesOrValues, onFulfilled, onRejected, onProgress) {432 checkCallbacks(1, arguments);433 return map(promisesOrValues, identity).then(onFulfilled, onRejected, onProgress);434 }435 /**436 * Joins multiple promises into a single returned promise.437 * @returns {Promise} a promise that will fulfill when *all* the input promises438 * have fulfilled, or will reject when *any one* of the input promises rejects.439 */440 function join(/* ...promises */) {441 return map(arguments, identity);442 }443 /**444 * Traditional map function, similar to `Array.prototype.map()`, but allows445 * input to contain {@link Promise}s and/or values, and mapFunc may return446 * either a value or a {@link Promise}447 *448 * @param {Array|Promise} promise array of anything, may contain a mix449 * of {@link Promise}s and values450 * @param {function} mapFunc mapping function mapFunc(value) which may return451 * either a {@link Promise} or value452 * @returns {Promise} a {@link Promise} that will resolve to an array containing453 * the mapped output values.454 */455 function map(promise, mapFunc) {456 return when(promise, function(array) {457 var results, len, toResolve, resolve, i, d;458 // Since we know the resulting length, we can preallocate the results459 // array to avoid array expansions.460 toResolve = len = array.length >>> 0;461 results = [];462 d = defer();463 if(!toResolve) {464 d.resolve(results);465 } else {466 resolve = function resolveOne(item, i) {467 when(item, mapFunc).then(function(mapped) {468 results[i] = mapped;469 if(!--toResolve) {470 d.resolve(results);471 }472 }, d.reject);473 };474 // Since mapFunc may be async, get all invocations of it into flight475 for(i = 0; i < len; i++) {476 if(i in array) {477 resolve(array[i], i);478 } else {479 --toResolve;480 }481 }482 }483 return d.promise;484 });485 }486 /**487 * Traditional reduce function, similar to `Array.prototype.reduce()`, but488 * input may contain promises and/or values, and reduceFunc489 * may return either a value or a promise, *and* initialValue may490 * be a promise for the starting value.491 *492 * @param {Array|Promise} promise array or promise for an array of anything,493 * may contain a mix of promises and values.494 * @param {function} reduceFunc reduce function reduce(currentValue, nextValue, index, total),495 * where total is the total number of items being reduced, and will be the same496 * in each call to reduceFunc.497 * @returns {Promise} that will resolve to the final reduced value498 */499 function reduce(promise, reduceFunc /*, initialValue */) {500 var args = slice.call(arguments, 1);501 return when(promise, function(array) {502 var total;503 total = array.length;504 // Wrap the supplied reduceFunc with one that handles promises and then505 // delegates to the supplied.506 args[0] = function (current, val, i) {507 return when(current, function (c) {508 return when(val, function (value) {509 return reduceFunc(c, value, i, total);510 });511 });512 };513 return reduceArray.apply(array, args);514 });515 }516 /**517 * Ensure that resolution of promiseOrValue will trigger resolver with the518 * value or reason of promiseOrValue, or instead with resolveValue if it is provided.519 *520 * @param promiseOrValue521 * @param {Object} resolver522 * @param {function} resolver.resolve523 * @param {function} resolver.reject524 * @param {*} [resolveValue]525 * @returns {Promise}526 */527 function chain(promiseOrValue, resolver, resolveValue) {528 var useResolveValue = arguments.length > 2;529 return when(promiseOrValue,530 function(val) {531 val = useResolveValue ? resolveValue : val;532 resolver.resolve(val);533 return val;534 },535 function(reason) {536 resolver.reject(reason);537 return rejected(reason);538 },539 resolver.progress540 );541 }542 //543 // Utility functions544 //545 /**546 * Apply all functions in queue to value547 * @param {Array} queue array of functions to execute548 * @param {*} value argument passed to each function549 */550 function processQueue(queue, value) {551 var handler, i = 0;552 while (handler = queue[i++]) {553 handler(value);554 }555 }556 /**557 * Helper that checks arrayOfCallbacks to ensure that each element is either558 * a function, or null or undefined.559 * @private560 * @param {number} start index at which to start checking items in arrayOfCallbacks561 * @param {Array} arrayOfCallbacks array to check562 * @throws {Error} if any element of arrayOfCallbacks is something other than563 * a functions, null, or undefined.564 */565 function checkCallbacks(start, arrayOfCallbacks) {566 // TODO: Promises/A+ update type checking and docs567 var arg, i = arrayOfCallbacks.length;568 while(i > start) {569 arg = arrayOfCallbacks[--i];570 if (arg != null && typeof arg != 'function') {571 throw new Error('arg '+i+' must be a function');572 }573 }574 }575 /**576 * No-Op function used in method replacement577 * @private578 */579 function noop() {}580 slice = [].slice;581 // ES5 reduce implementation if native not available582 // See: http://es5.github.com/#x15.4.4.21 as there are many583 // specifics and edge cases.584 reduceArray = [].reduce ||585 function(reduceFunc /*, initialValue */) {586 /*jshint maxcomplexity: 7*/587 // ES5 dictates that reduce.length === 1588 // This implementation deviates from ES5 spec in the following ways:589 // 1. It does not check if reduceFunc is a Callable590 var arr, args, reduced, len, i;591 i = 0;592 // This generates a jshint warning, despite being valid593 // "Missing 'new' prefix when invoking a constructor."594 // See https://github.com/jshint/jshint/issues/392595 arr = Object(this);596 len = arr.length >>> 0;597 args = arguments;598 // If no initialValue, use first item of array (we know length !== 0 here)599 // and adjust i to start at second item600 if(args.length <= 1) {601 // Skip to the first real element in the array602 for(;;) {603 if(i in arr) {604 reduced = arr[i++];605 break;606 }607 // If we reached the end of the array without finding any real608 // elements, it's a TypeError609 if(++i >= len) {610 throw new TypeError();611 }612 }613 } else {614 // If initialValue provided, use it615 reduced = args[1];616 }617 // Do the actual reduce618 for(;i < len; ++i) {619 // Skip holes620 if(i in arr) {621 reduced = reduceFunc(reduced, arr[i], i, arr);622 }623 }624 return reduced;625 };626 function identity(x) {627 return x;628 }629 return when;630});631})(typeof define == 'function' && define.amd632 ? define633 : function (factory) { typeof exports === 'object'634 ? (module.exports = factory())635 : (this.when = factory());636 }637 // Boilerplate for AMD, Node, and browser global...

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promise.js

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1// Copyright 2012 the V8 project authors. All rights reserved.2// Use of this source code is governed by a BSD-style license that can be3// found in the LICENSE file.4(function(global, utils, extrasUtils) {5"use strict";6%CheckIsBootstrapping();7// -------------------------------------------------------------------8// Imports9var InternalArray = utils.InternalArray;10var MakeTypeError;11var promiseCombinedDeferredSymbol =12 utils.ImportNow("promise_combined_deferred_symbol");13var promiseHasHandlerSymbol =14 utils.ImportNow("promise_has_handler_symbol");15var promiseRejectReactionsSymbol =16 utils.ImportNow("promise_reject_reactions_symbol");17var promiseFulfillReactionsSymbol =18 utils.ImportNow("promise_fulfill_reactions_symbol");19var promiseDeferredReactionsSymbol =20 utils.ImportNow("promise_deferred_reactions_symbol");21var promiseRawSymbol = utils.ImportNow("promise_raw_symbol");22var promiseStateSymbol = utils.ImportNow("promise_state_symbol");23var promiseResultSymbol = utils.ImportNow("promise_result_symbol");24var SpeciesConstructor;25var speciesSymbol = utils.ImportNow("species_symbol");26var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");27utils.Import(function(from) {28 MakeTypeError = from.MakeTypeError;29 SpeciesConstructor = from.SpeciesConstructor;30});31// -------------------------------------------------------------------32// [[PromiseState]] values:33const kPending = 0;34const kFulfilled = +1;35const kRejected = -1;36var lastMicrotaskId = 0;37// ES#sec-createresolvingfunctions38// CreateResolvingFunctions ( promise )39function CreateResolvingFunctions(promise) {40 var alreadyResolved = false;41 // ES#sec-promise-resolve-functions42 // Promise Resolve Functions43 var resolve = value => {44 if (alreadyResolved === true) return;45 alreadyResolved = true;46 ResolvePromise(promise, value);47 };48 // ES#sec-promise-reject-functions49 // Promise Reject Functions50 var reject = reason => {51 if (alreadyResolved === true) return;52 alreadyResolved = true;53 RejectPromise(promise, reason);54 };55 return {56 __proto__: null,57 resolve: resolve,58 reject: reject59 };60}61// ES#sec-promise-executor62// Promise ( executor )63var GlobalPromise = function Promise(executor) {64 if (executor === promiseRawSymbol) {65 return %_NewObject(GlobalPromise, new.target);66 }67 if (IS_UNDEFINED(new.target)) throw MakeTypeError(kNotAPromise, this);68 if (!IS_CALLABLE(executor)) {69 throw MakeTypeError(kResolverNotAFunction, executor);70 }71 var promise = PromiseInit(%_NewObject(GlobalPromise, new.target));72 var callbacks = CreateResolvingFunctions(promise);73 var debug_is_active = DEBUG_IS_ACTIVE;74 try {75 if (debug_is_active) %DebugPushPromise(promise, Promise);76 executor(callbacks.resolve, callbacks.reject);77 } catch (e) {78 %_Call(callbacks.reject, UNDEFINED, e);79 } finally {80 if (debug_is_active) %DebugPopPromise();81 }82 return promise;83}84// Core functionality.85function PromiseSet(promise, status, value) {86 SET_PRIVATE(promise, promiseStateSymbol, status);87 SET_PRIVATE(promise, promiseResultSymbol, value);88 // There are 3 possible states for the resolve, reject symbols when we add89 // a new callback --90 // 1) UNDEFINED -- This is the zero state where there is no callback91 // registered. When we see this state, we directly attach the callbacks to92 // the symbol.93 // 2) !IS_ARRAY -- There is a single callback directly attached to the94 // symbols. We need to create a new array to store additional callbacks.95 // 3) IS_ARRAY -- There are multiple callbacks already registered,96 // therefore we can just push the new callback to the existing array.97 SET_PRIVATE(promise, promiseFulfillReactionsSymbol, UNDEFINED);98 SET_PRIVATE(promise, promiseRejectReactionsSymbol, UNDEFINED);99 // There are 2 possible states for this symbol --100 // 1) UNDEFINED -- This is the zero state, no deferred object is101 // attached to this symbol. When we want to add a new deferred we102 // directly attach it to this symbol.103 // 2) symbol with attached deferred object -- New deferred objects104 // are not attached to this symbol, but instead they are directly105 // attached to the resolve, reject callback arrays. At this point,106 // the deferred symbol's state is stale, and the deferreds should be107 // read from the reject, resolve callbacks.108 SET_PRIVATE(promise, promiseDeferredReactionsSymbol, UNDEFINED);109 return promise;110}111function PromiseCreateAndSet(status, value) {112 var promise = new GlobalPromise(promiseRawSymbol);113 // If debug is active, notify about the newly created promise first.114 if (DEBUG_IS_ACTIVE) PromiseSet(promise, kPending, UNDEFINED);115 return PromiseSet(promise, status, value);116}117function PromiseInit(promise) {118 return PromiseSet(promise, kPending, UNDEFINED);119}120function FulfillPromise(promise, status, value, promiseQueue) {121 if (GET_PRIVATE(promise, promiseStateSymbol) === kPending) {122 var tasks = GET_PRIVATE(promise, promiseQueue);123 if (!IS_UNDEFINED(tasks)) {124 var tasks = GET_PRIVATE(promise, promiseQueue);125 var deferreds = GET_PRIVATE(promise, promiseDeferredReactionsSymbol);126 PromiseEnqueue(value, tasks, deferreds, status);127 }128 PromiseSet(promise, status, value);129 }130}131function PromiseHandle(value, handler, deferred) {132 var debug_is_active = DEBUG_IS_ACTIVE;133 try {134 if (debug_is_active) %DebugPushPromise(deferred.promise, PromiseHandle);135 var result = handler(value);136 deferred.resolve(result);137 } catch (exception) {138 try { deferred.reject(exception); } catch (e) { }139 } finally {140 if (debug_is_active) %DebugPopPromise();141 }142}143function PromiseEnqueue(value, tasks, deferreds, status) {144 var id, name, instrumenting = DEBUG_IS_ACTIVE;145 %EnqueueMicrotask(function() {146 if (instrumenting) {147 %DebugAsyncTaskEvent({ type: "willHandle", id: id, name: name });148 }149 if (IS_ARRAY(tasks)) {150 for (var i = 0; i < tasks.length; i += 2) {151 PromiseHandle(value, tasks[i], tasks[i + 1]);152 }153 } else {154 PromiseHandle(value, tasks, deferreds);155 }156 if (instrumenting) {157 %DebugAsyncTaskEvent({ type: "didHandle", id: id, name: name });158 }159 });160 if (instrumenting) {161 id = ++lastMicrotaskId;162 name = status === kFulfilled ? "Promise.resolve" : "Promise.reject";163 %DebugAsyncTaskEvent({ type: "enqueue", id: id, name: name });164 }165}166function PromiseAttachCallbacks(promise, deferred, onResolve, onReject) {167 var maybeResolveCallbacks =168 GET_PRIVATE(promise, promiseFulfillReactionsSymbol);169 if (IS_UNDEFINED(maybeResolveCallbacks)) {170 SET_PRIVATE(promise, promiseFulfillReactionsSymbol, onResolve);171 SET_PRIVATE(promise, promiseRejectReactionsSymbol, onReject);172 SET_PRIVATE(promise, promiseDeferredReactionsSymbol, deferred);173 } else if (!IS_ARRAY(maybeResolveCallbacks)) {174 var resolveCallbacks = new InternalArray();175 var rejectCallbacks = new InternalArray();176 var existingDeferred = GET_PRIVATE(promise, promiseDeferredReactionsSymbol);177 resolveCallbacks.push(178 maybeResolveCallbacks, existingDeferred, onResolve, deferred);179 rejectCallbacks.push(GET_PRIVATE(promise, promiseRejectReactionsSymbol),180 existingDeferred,181 onReject,182 deferred);183 SET_PRIVATE(promise, promiseFulfillReactionsSymbol, resolveCallbacks);184 SET_PRIVATE(promise, promiseRejectReactionsSymbol, rejectCallbacks);185 } else {186 maybeResolveCallbacks.push(onResolve, deferred);187 GET_PRIVATE(promise, promiseRejectReactionsSymbol).push(onReject, deferred);188 }189}190function PromiseIdResolveHandler(x) { return x }191function PromiseIdRejectHandler(r) { throw r }192function PromiseNopResolver() {}193// -------------------------------------------------------------------194// Define exported functions.195// For bootstrapper.196// ES#sec-ispromise IsPromise ( x )197function IsPromise(x) {198 return IS_RECEIVER(x) && HAS_DEFINED_PRIVATE(x, promiseStateSymbol);199}200function PromiseCreate() {201 return new GlobalPromise(PromiseNopResolver)202}203// ES#sec-promise-resolve-functions204// Promise Resolve Functions, steps 6-13205function ResolvePromise(promise, resolution) {206 if (resolution === promise) {207 return RejectPromise(promise, MakeTypeError(kPromiseCyclic, resolution));208 }209 if (IS_RECEIVER(resolution)) {210 // 25.4.1.3.2 steps 8-12211 try {212 var then = resolution.then;213 } catch (e) {214 return RejectPromise(promise, e);215 }216 // Resolution is a native promise and if it's already resolved or217 // rejected, shortcircuit the resolution procedure by directly218 // reusing the value from the promise.219 if (IsPromise(resolution) && then === PromiseThen) {220 var thenableState = GET_PRIVATE(resolution, promiseStateSymbol);221 if (thenableState === kFulfilled) {222 // This goes inside the if-else to save one symbol lookup in223 // the slow path.224 var thenableValue = GET_PRIVATE(resolution, promiseResultSymbol);225 FulfillPromise(promise, kFulfilled, thenableValue,226 promiseFulfillReactionsSymbol);227 SET_PRIVATE(promise, promiseHasHandlerSymbol, true);228 return;229 } else if (thenableState === kRejected) {230 var thenableValue = GET_PRIVATE(resolution, promiseResultSymbol);231 if (!HAS_DEFINED_PRIVATE(resolution, promiseHasHandlerSymbol)) {232 // Promise has already been rejected, but had no handler.233 // Revoke previously triggered reject event.234 %PromiseRevokeReject(resolution);235 }236 RejectPromise(promise, thenableValue);237 SET_PRIVATE(resolution, promiseHasHandlerSymbol, true);238 return;239 }240 }241 if (IS_CALLABLE(then)) {242 // PromiseResolveThenableJob243 var id;244 var name = "PromiseResolveThenableJob";245 var instrumenting = DEBUG_IS_ACTIVE;246 %EnqueueMicrotask(function() {247 if (instrumenting) {248 %DebugAsyncTaskEvent({ type: "willHandle", id: id, name: name });249 }250 var callbacks = CreateResolvingFunctions(promise);251 try {252 %_Call(then, resolution, callbacks.resolve, callbacks.reject);253 } catch (e) {254 %_Call(callbacks.reject, UNDEFINED, e);255 }256 if (instrumenting) {257 %DebugAsyncTaskEvent({ type: "didHandle", id: id, name: name });258 }259 });260 if (instrumenting) {261 id = ++lastMicrotaskId;262 %DebugAsyncTaskEvent({ type: "enqueue", id: id, name: name });263 }264 return;265 }266 }267 FulfillPromise(promise, kFulfilled, resolution, promiseFulfillReactionsSymbol);268}269// ES#sec-rejectpromise270// RejectPromise ( promise, reason )271function RejectPromise(promise, reason) {272 // Check promise status to confirm that this reject has an effect.273 // Call runtime for callbacks to the debugger or for unhandled reject.274 if (GET_PRIVATE(promise, promiseStateSymbol) === kPending) {275 var debug_is_active = DEBUG_IS_ACTIVE;276 if (debug_is_active ||277 !HAS_DEFINED_PRIVATE(promise, promiseHasHandlerSymbol)) {278 %PromiseRejectEvent(promise, reason, debug_is_active);279 }280 }281 FulfillPromise(promise, kRejected, reason, promiseRejectReactionsSymbol)282}283// ES#sec-newpromisecapability284// NewPromiseCapability ( C )285function NewPromiseCapability(C) {286 if (C === GlobalPromise) {287 // Optimized case, avoid extra closure.288 var promise = PromiseInit(new GlobalPromise(promiseRawSymbol));289 var callbacks = CreateResolvingFunctions(promise);290 return {291 promise: promise,292 resolve: callbacks.resolve,293 reject: callbacks.reject294 };295 }296 var result = {promise: UNDEFINED, resolve: UNDEFINED, reject: UNDEFINED };297 result.promise = new C((resolve, reject) => {298 if (!IS_UNDEFINED(result.resolve) || !IS_UNDEFINED(result.reject))299 throw MakeTypeError(kPromiseExecutorAlreadyInvoked);300 result.resolve = resolve;301 result.reject = reject;302 });303 if (!IS_CALLABLE(result.resolve) || !IS_CALLABLE(result.reject))304 throw MakeTypeError(kPromiseNonCallable);305 return result;306}307// Unspecified V8-specific legacy function308function PromiseDefer() {309 %IncrementUseCounter(kPromiseDefer);310 return NewPromiseCapability(this);311}312// Unspecified V8-specific legacy function313function PromiseAccept(x) {314 %IncrementUseCounter(kPromiseAccept);315 return %_Call(PromiseResolve, this, x);316}317// ES#sec-promise.reject318// Promise.reject ( x )319function PromiseReject(r) {320 if (!IS_RECEIVER(this)) {321 throw MakeTypeError(kCalledOnNonObject, PromiseResolve);322 }323 if (this === GlobalPromise) {324 // Optimized case, avoid extra closure.325 var promise = PromiseCreateAndSet(kRejected, r);326 // The debug event for this would always be an uncaught promise reject,327 // which is usually simply noise. Do not trigger that debug event.328 %PromiseRejectEvent(promise, r, false);329 return promise;330 } else {331 var promiseCapability = NewPromiseCapability(this);332 %_Call(promiseCapability.reject, UNDEFINED, r);333 return promiseCapability.promise;334 }335}336// Shortcut Promise.reject and Promise.resolve() implementations, used by337// Async Functions implementation.338function PromiseCreateRejected(r) {339 return %_Call(PromiseReject, GlobalPromise, r);340}341function PromiseCreateResolved(x) {342 return %_Call(PromiseResolve, GlobalPromise, x);343}344// ES#sec-promise.prototype.then345// Promise.prototype.then ( onFulfilled, onRejected )346// Multi-unwrapped chaining with thenable coercion.347function PromiseThen(onResolve, onReject) {348 var status = GET_PRIVATE(this, promiseStateSymbol);349 if (IS_UNDEFINED(status)) {350 throw MakeTypeError(kNotAPromise, this);351 }352 var constructor = SpeciesConstructor(this, GlobalPromise);353 onResolve = IS_CALLABLE(onResolve) ? onResolve : PromiseIdResolveHandler;354 onReject = IS_CALLABLE(onReject) ? onReject : PromiseIdRejectHandler;355 var deferred = NewPromiseCapability(constructor);356 switch (status) {357 case kPending:358 PromiseAttachCallbacks(this, deferred, onResolve, onReject);359 break;360 case kFulfilled:361 PromiseEnqueue(GET_PRIVATE(this, promiseResultSymbol),362 onResolve, deferred, kFulfilled);363 break;364 case kRejected:365 if (!HAS_DEFINED_PRIVATE(this, promiseHasHandlerSymbol)) {366 // Promise has already been rejected, but had no handler.367 // Revoke previously triggered reject event.368 %PromiseRevokeReject(this);369 }370 PromiseEnqueue(GET_PRIVATE(this, promiseResultSymbol),371 onReject, deferred, kRejected);372 break;373 }374 // Mark this promise as having handler.375 SET_PRIVATE(this, promiseHasHandlerSymbol, true);376 return deferred.promise;377}378// Unspecified V8-specific legacy function379// Chain is left around for now as an alias for then380function PromiseChain(onResolve, onReject) {381 %IncrementUseCounter(kPromiseChain);382 return %_Call(PromiseThen, this, onResolve, onReject);383}384// ES#sec-promise.prototype.catch385// Promise.prototype.catch ( onRejected )386function PromiseCatch(onReject) {387 return this.then(UNDEFINED, onReject);388}389// Combinators.390// ES#sec-promise.resolve391// Promise.resolve ( x )392function PromiseResolve(x) {393 if (!IS_RECEIVER(this)) {394 throw MakeTypeError(kCalledOnNonObject, PromiseResolve);395 }396 if (IsPromise(x) && x.constructor === this) return x;397 var promiseCapability = NewPromiseCapability(this);398 var resolveResult = %_Call(promiseCapability.resolve, UNDEFINED, x);399 return promiseCapability.promise;400}401// ES#sec-promise.all402// Promise.all ( iterable )403function PromiseAll(iterable) {404 if (!IS_RECEIVER(this)) {405 throw MakeTypeError(kCalledOnNonObject, "Promise.all");406 }407 var deferred = NewPromiseCapability(this);408 var resolutions = new InternalArray();409 var count;410 function CreateResolveElementFunction(index, values, promiseCapability) {411 var alreadyCalled = false;412 return (x) => {413 if (alreadyCalled === true) return;414 alreadyCalled = true;415 values[index] = x;416 if (--count === 0) {417 var valuesArray = [];418 %MoveArrayContents(values, valuesArray);419 %_Call(promiseCapability.resolve, UNDEFINED, valuesArray);420 }421 };422 }423 try {424 var i = 0;425 count = 1;426 for (var value of iterable) {427 var nextPromise = this.resolve(value);428 ++count;429 nextPromise.then(430 CreateResolveElementFunction(i, resolutions, deferred),431 deferred.reject);432 SET_PRIVATE(deferred.reject, promiseCombinedDeferredSymbol, deferred);433 ++i;434 }435 // 6.d436 if (--count === 0) {437 var valuesArray = [];438 %MoveArrayContents(resolutions, valuesArray);439 %_Call(deferred.resolve, UNDEFINED, valuesArray);440 }441 } catch (e) {442 %_Call(deferred.reject, UNDEFINED, e);443 }444 return deferred.promise;445}446// ES#sec-promise.race447// Promise.race ( iterable )448function PromiseRace(iterable) {449 if (!IS_RECEIVER(this)) {450 throw MakeTypeError(kCalledOnNonObject, PromiseRace);451 }452 var deferred = NewPromiseCapability(this);453 try {454 for (var value of iterable) {455 this.resolve(value).then(deferred.resolve, deferred.reject);456 SET_PRIVATE(deferred.reject, promiseCombinedDeferredSymbol, deferred);457 }458 } catch (e) {459 deferred.reject(e)460 }461 return deferred.promise;462}463// Utility for debugger464function PromiseHasUserDefinedRejectHandlerCheck(handler, deferred) {465 if (handler !== PromiseIdRejectHandler) {466 var combinedDeferred = GET_PRIVATE(handler, promiseCombinedDeferredSymbol);467 if (IS_UNDEFINED(combinedDeferred)) return true;468 if (PromiseHasUserDefinedRejectHandlerRecursive(combinedDeferred.promise)) {469 return true;470 }471 } else if (PromiseHasUserDefinedRejectHandlerRecursive(deferred.promise)) {472 return true;473 }474 return false;475}476function PromiseHasUserDefinedRejectHandlerRecursive(promise) {477 var queue = GET_PRIVATE(promise, promiseRejectReactionsSymbol);478 var deferreds = GET_PRIVATE(promise, promiseDeferredReactionsSymbol);479 if (IS_UNDEFINED(queue)) return false;480 if (!IS_ARRAY(queue)) {481 return PromiseHasUserDefinedRejectHandlerCheck(queue, deferreds);482 } else {483 for (var i = 0; i < queue.length; i += 2) {484 if (PromiseHasUserDefinedRejectHandlerCheck(queue[i], queue[i + 1])) {485 return true;486 }487 }488 }489 return false;490}491// Return whether the promise will be handled by a user-defined reject492// handler somewhere down the promise chain. For this, we do a depth-first493// search for a reject handler that's not the default PromiseIdRejectHandler.494function PromiseHasUserDefinedRejectHandler() {495 return PromiseHasUserDefinedRejectHandlerRecursive(this);496};497function PromiseSpecies() {498 return this;499}500// -------------------------------------------------------------------501// Install exported functions.502%AddNamedProperty(global, 'Promise', GlobalPromise, DONT_ENUM);503%AddNamedProperty(GlobalPromise.prototype, toStringTagSymbol, "Promise",504 DONT_ENUM | READ_ONLY);505utils.InstallFunctions(GlobalPromise, DONT_ENUM, [506 "reject", PromiseReject,507 "all", PromiseAll,508 "race", PromiseRace,509 "resolve", PromiseResolve510]);511utils.InstallGetter(GlobalPromise, speciesSymbol, PromiseSpecies);512utils.InstallFunctions(GlobalPromise.prototype, DONT_ENUM, [513 "then", PromiseThen,514 "catch", PromiseCatch515]);516%InstallToContext([517 "promise_catch", PromiseCatch,518 "promise_chain", PromiseChain,519 "promise_create", PromiseCreate,520 "promise_has_user_defined_reject_handler", PromiseHasUserDefinedRejectHandler,521 "promise_reject", RejectPromise,522 "promise_resolve", ResolvePromise,523 "promise_then", PromiseThen,524 "promise_create_rejected", PromiseCreateRejected,525 "promise_create_resolved", PromiseCreateResolved526]);527// This allows extras to create promises quickly without building extra528// resolve/reject closures, and allows them to later resolve and reject any529// promise without having to hold on to those closures forever.530utils.InstallFunctions(extrasUtils, 0, [531 "createPromise", PromiseCreate,532 "resolvePromise", ResolvePromise,533 "rejectPromise", RejectPromise534]);535// TODO(v8:4567): Allow experimental natives to remove function prototype536[PromiseChain, PromiseDefer, PromiseAccept].forEach(537 fn => %FunctionRemovePrototype(fn));538utils.Export(function(to) {539 to.PromiseChain = PromiseChain;540 to.PromiseDefer = PromiseDefer;541 to.PromiseAccept = PromiseAccept;542 to.PromiseCreateRejected = PromiseCreateRejected;543 to.PromiseCreateResolved = PromiseCreateResolved;544 to.PromiseThen = PromiseThen;545});...

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知乎大佬自己写的promise.js

Source:知乎大佬自己写的promise.js Github

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1// 定义三种状态2const REJECTED = 'REJECTED';3const FULFILLED = 'FULFILLED';4const PENDING = 'PENDING';5/**6 * 判断一个变量是否是 Promise 的函数7 * 1. 是否是对象并且不是 null8 * 2. 是否有 then 属性并且 then 是一个方法9 * @param {*} val 10 */11function isPromise(val) {12 if (typeof val === 'object' && val !== null || typeof val === 'function') {13 return typeof val.then === 'function';14 }15 return false;16}17console.log('--------------------- MY Promise ---------------------');18// 实现链式调用19/**20 * 处理 then 中的成功、失败回调函数返回值是否是 Promise 的情况21 * @param {*} promise2 参见 Promise A+ 规范说明 new Promise22 * @param {*} x 是成功、失败回调的返回值23 */24const resolvePromise = (promise2, x) => {25 const { resolve, reject } = promise2;26 // 这里的判断是可能自己的 Promise 要和别人的 Promise 混用,可能不同的 Promise 库之间相互调用27 // 如果 new 出来的 Promise2 和 x 是同一个,那么 x 永远不能成功或者失败,所以卡死了,直接报错28 if (promise2 === x) return reject(new TypeError('Chaining cycle detected for promise #<Promise>'));29 // 需要判断 x 的状态,判断 x 是不是 Promise30 // 先判断是不是对象或者函数31 if (typeof x === 'object' && x !== null || typeof x === 'function') {32 let called; // 这里考虑别人的 Promise 是否健壮,不健壮需要再判断一下,调用了成功就不能失败,调用的失败就不能成功。不能多次调用成功或者失败33 try {34 const then = x.then; // 内部可能抛出错误35 // 如果 then 不是函数就说明是一个普通值,直接返回 x 36 if (typeof then !== 'function') resolve(x); // 比如:{ then: 'mhq' }37 else {38 // 这里不要再次调用 x.then 是防止取 then 的时候报错,万一 then 方法里面抛出了一个错误呢?39 then.call(x, y => {40 if (called) return;41 called = true;42 // 如果 x 是一个 Promise,那么就继续解析成功的值43 resolvePromise(promise2, y);44 }, f => {45 if (called) return;46 called = true;47 reject(f); // 直接调用 r 作为失败的结果48 });49 }50 } catch (err) {51 if (called) return;52 called = true;53 reject(err);54 }55 } else {56 resolve(x);57 }58};59class Promise {60 constructor(executor) {61 // Promise 的状态62 this.status = PENDING;63 // 成功后的值64 this.value = undefined;65 // 失败后的值66 this.reason = undefined;67 // 成功回调函数,发布订阅68 this.onResolvedCallbacks = [];69 // 失败回调函数,发布订阅70 this.onRejectedCallbacks = [];71 /**72 * Promise 内部提供的 resolve,让 Promise 的状态变成成功态,并让成功回调执行73 * @param {*} value 74 */75 const resolve = value => {76 if (value instanceof Promise) {77 return value.then(resolve, reject);78 }79 if (this.status === PENDING) {80 this.status = FULFILLED;81 this.value = value;82 this.onResolvedCallbacks.forEach(fn => fn());83 }84 };85 /**86 * Promise 内部提供的 reject,让 Promise 的状态变成失败态,并让失败回调执行87 * @param {*} reason 88 */89 const reject = reason => {90 if (this.status === PENDING) {91 this.status = REJECTED;92 this.reason = reason;93 this.onRejectedCallbacks.forEach(fn => fn());94 }95 };96 // try + catch 只能捕获同步异常97 try {98 executor(resolve, reject);99 } catch (err) {100 reject(err);101 }102 }103 // 只要 x 是一个普通值,就会让一个 Promise 变成成功态104 // 这个 x 有可能是一个 Promise,需要菜哟个这个 Promise 的状态105 then(onFulfilled, onRejected) {106 // 比如.then().then().then(() => {}); 这种调用,对可选参数的处理,透传107 onFulfilled = typeof onFulfilled === 'function' ? onFulfilled : val => val;108 onRejected = typeof onRejected === 'function' ? onRejected : err => { throw err };109 const promise2 = new Promise((resolve, reject) => { // 一旦 new 则立即执行110 if (this.status === FULFILLED) {111 setTimeout(() => {112 promise2.resolve = resolve;113 promise2.reject = reject;114 try {115 const x = onFulfilled(this.value);116 resolvePromise(promise2, x);117 } catch (err) {118 reject(err);119 }120 }, 0);121 }122 if (this.status === REJECTED) {123 setTimeout(() => {124 promise2.resolve = resolve;125 promise2.reject = reject;126 try {127 const x = onRejected(this.reason);128 resolvePromise(promise2, x);129 } catch (err) {130 reject(err);131 }132 }, 0);133 }134 if (this.status === PENDING) { // 本身是异步的135 this.onResolvedCallbacks.push(() => {136 setTimeout(() => { // 这里需要加上,不加上跑测试跑不通137 promise2.resolve = resolve;138 promise2.reject = reject;139 try {140 const x = onFulfilled(this.value);141 resolvePromise(promise2, x);142 } catch (err) {143 reject(err);144 }145 });146 });147 this.onRejectedCallbacks.push(() => {148 setTimeout(() => {149 promise2.resolve = resolve;150 promise2.reject = reject;151 try {152 const x = onRejected(this.reason);153 resolvePromise(promise2, x);154 } catch (err) {155 reject(err);156 }157 });158 });159 }160 });161 return promise2;162 }163 /**164 * Promise 中的 catch 指代的就是 then 没有成功回调的一个别名而已165 * @param {*} errCallback 166 */167 catch(errCallback) {168 return this.then(null, errCallback);169 }170}171// 无论如何都会执行,把上一个 then 的结果向下传递,如果 finally 中返回了一个 Promise 会等待这个 Promise 执行完成后继续执行172Promise.prototype.finally = function (callback) {173 return this.then(val => {174 return Promise.resolve(callback()).then(() => val);175 }, (err) => {176 return Promise.resolve(callback()).then(() => {177 throw err;178 });179 });180};181// npm install promises-aplus-tests -g182// promises-aplus-tests promise.js183// 测试自己写的 Promise 是否符合规范的包184Promise.deferred = () => {185 const dfd = {};186 dfd.promise = new Promise((resolve, reject) => {187 dfd.resolve = resolve;188 dfd.reject = reject;189 });190 return dfd;191};192/**193 * Promise.resolve 他会等待里面的 Promise 执行成功194 * @param {*} val 195 */196Promise.resolve = val => {197 return new Promise((resolve) => {198 resolve(val);199 });200};201/**202 * Promise.reject 不会等待参数中的 Promise 执行完毕203 */204Promise.reject = () => {205 return new Promise((_, reject) => {206 reject(val);207 });208};209/**210 * Promise.all 方法表示等待所有的 Promise 全部成功后才会执行回调,如果有一个 Promise 失败则 Promise 就失败了211 * @param {*} promises 212 */213Promise.all = promises => {214 return new Promise((resolve, reject) => {215 const res = [];216 let count = 0;217 const resolveRes = (index, data) => {218 res[index] = data;219 if (++count === promises.length) {220 resolve(res);221 }222 };223 for (let i = 0; i < promises.length; i++) {224 const current = promises[i];225 if (isPromise(current)) {226 current.then((data) => {227 resolveRes(i, data);228 }, (err) => {229 reject(err);230 });231 } else {232 resolveRes(i, current);233 }234 }235 });236}237/**238 * Promise.race 赛跑,谁是第一个完成的,就用他的结果,如果是失败这个 Promise 就失败,如果第一个是成功就是成功239 * @param {*} promises 240 */241Promise.race = (promises) => {242 return new Promise((resolve, reject) => {243 for (let i = 0; i < promises.length; i++) {244 let current = promises[i];245 if (isPromise(current)) {246 current.then(resolve, reject);247 } else {248 resolve(current);249 break;250 }251 }252 });253}254// 专门给 node 的 api 做的 promisify 方法,如 fs.readFile255Promise.promisify = fn => {256 return (...arg) => {257 return new Promise((resolve, reject) => {258 fn(...arg, (err, data) => {259 if (err) reject(err);260 resolve(data);261 });262 });263 }264};265module.exports = Promise;266var p = {267 then: (resolve, reject) => {268 setTimeout(() => {269 resolve(1)270 }, 1000);271 }272}273var p1 = new Promise(274 (resolve, reject) => {275 resolve(p)276 }277)278p1.then((res) => {279 console.log(res);...

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index.js

Source:index.js Github

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1/* 2.3 The Promise Resolution Procedure */2function resolvePromise(promise, x) {3 try {4 // 2.3.1 If promise and x refer to the same object, reject promise with a TypeError as the reason.5 if (promise === x) {6 throw new TypeError('promise cannot be resolved with itself.');7 }8 // 2.3.2 If x is promise9 // 2.3.3 If x is an object or function10 if (11 x &&12 (typeof x === 'object' || typeof x === 'function')13 ) {14 var then = x.then;15 // 2.3.3.3 If then is a function, call it with x as this, first argument resolvePromise, and second argument rejectPromise16 if (typeof then === 'function') {17 startResolve(promise, function (resolve, reject) {18 then.call(x, resolve, reject);19 });20 return;21 }22 }23 // 2.3.3.4 If then is not a function, fulfill promise with x.24 // 2.3.4 If x is not an object or function, fulfill promise with x.25 doResolve(promise, x);26 } catch (e) {27 // 2.3.3.2 If retrieving the property x.then results in a thrown exception e, reject promise with e as the reason28 // 2.3.3.3.4.2 If calling then throws an exception e, reject promise with e as the reason.29 doReject(promise, e);30 }31}32function doResolve(promise, value) {33 promise._state = 'resolved';34 promise._value = value;35 _handleDeferreds(promise);36}37function doReject(promise, reason) {38 promise._state = 'rejected';39 promise._value = reason;40 _handleDeferreds(promise);41}42function startResolve(promise, fn) {43 var called = false;44 if (typeof fn !== 'function') {45 throw new Error('Promise procedure must be a function.');46 }47 try {48 fn(49 function (value) {50 // 2.2.2.3 onFulfilled must not be called more than once.51 if (called) return;52 if (promise._state === 'pending') {53 called = true;54 resolvePromise(promise, value);55 }56 },57 function (reason) {58 // 2.2.3.3 onRejected must not be called more than once.59 if (called) return;60 if (promise._state === 'pending') {61 called = true;62 doReject(promise, reason);63 }64 }65 );66 } catch (e) {67 // 2.3.3.3.4.1 If resolvePromise or rejectPromise have been called, ignore it.68 if (called) return;69 if (promise._state === 'pending') {70 called = true;71 doReject(promise, e);72 }73 }74}75function Promise(fn) {76 if (typeof fn !== 'function') {77 throw new Error('Promise resolver is not a function');78 }79 this._state = 'pending';80 this._value = null;81 this._deferreds = [];82 startResolve(this, fn);83}84/*85* 2.2.6 Then may be called multiple times on the same promise.86* All respective callbacks must execute in the order of their originating calls to then.87*/88function _handleDeferreds(promise) {89 // 2.2.4 onFulfilled or onRejected must not be called until the execution context stack contains only platform code.90 setTimeout(function () {91 var deferreds = promise._deferreds;92 var state = promise._state;93 while (deferreds.length) {94 var defer = deferreds.shift();95 try {96 resolvePromise(97 defer.promise,98 defer[state === 'resolved' ? 'onFulfilled' : 'onRejected'](promise._value)99 );100 } catch (e) {101 doReject(defer.promise, e);102 }103 }104 }, 0);105}106function _handleThen(promise, onFulfilled, onRejected) {107 var promise2;108 if (promise._state === 'pending') {109 promise2 = new Promise(function () {});110 promise._deferreds.push({111 onFulfilled: onFulfilled,112 onRejected: onRejected,113 promise: promise2114 });115 } else {116 promise2 = new Promise(function (resolve, reject) {117 setTimeout(function () {118 try {119 // 2.2.7.1 If either onFulfilled or onRejected returns a value x, run the Promise Resolution Procedure [[Resolve]](promise2, x).120 var fn = promise._state === 'resolved' ? onFulfilled : onRejected;121 resolve(fn(promise._value));122 } catch (e) {123 // 2.2.7.2 If either onFulfilled or onRejected throws an exception e, promise2 must be rejected with e as the reason.124 reject(e);125 }126 }, 0);127 });128 }129 return promise2;130}131Promise.prototype.then = function (onFulfilled, onRejected) {132 // 2.2.7.3 If onFulfilled is not a function and promise1 is fulfilled, promise2 must be fulfilled with the same value as promise1.133 onFulfilled = typeof onFulfilled === 'function' ? onFulfilled : function (value) {134 return value;135 };136 // 2.2.7.4 If onRejected is not a function and promise1 is rejected, promise2 must be rejected with the same reason as promise1.137 onRejected = typeof onRejected === 'function' ? onRejected : function (reason) {138 throw reason;139 };140 return _handleThen(this, onFulfilled, onRejected);141};142Promise.prototype.catch = function (onRejected) {143 return this.then(null, onRejected);144};145Promise.prototype.finally = function (fn) {146 return this.then(147 function (value) {148 return fn(value);149 },150 function (reason) {151 return fn(reason);152 }153 );154};155Promise.resolve = function (value) {156 return new Promise(function (resolve) {157 resolve(value);158 });159};160Promise.reject = function (reason) {161 return new Promise(function (resolve, reject) {162 reject(reason);163 });164};165Promise.all = function (defers) {166 if (!Array.isArray(defers)) {167 throw 'Promise.all only accepts Array.';168 }169 var results = [].concat(defers);170 var remain = defers.length;171 return new Promise(function (resolve, reject) {172 if (remain === 0) {173 resolve([]);174 return;175 }176 var getRes = function (x, i) {177 try {178 if (179 x &&180 (typeof x === 'object' || typeof x === 'function')181 ) {182 var then = x.then;183 if (typeof then === 'function') {184 then.call(x, function (value) {185 getRes(value, i);186 }, reject);187 return;188 }189 }190 results[i] = x;191 if (--remain === 0) {192 resolve(results);193 }194 } catch (e) {195 reject(e);196 }197 }198 defers.forEach(function (defer, idx) {199 getRes(defer, idx);200 });201 });202};203Promise.race = function (defers) {204 if (!Array.isArray(defers)) {205 throw 'Promise.race only accepts Array.';206 }207 return new Promise(function (resolve, reject) {208 var getRes = function (x) {209 try {210 if (211 x &&212 (typeof x === 'object' || typeof x === 'function')213 ) {214 var then = x.then;215 if (typeof then === 'function') {216 then.call(x, resolve, reject);217 return;218 }219 }220 resolve(x);221 } catch (e) {222 reject(e);223 }224 };225 defers.forEach(function (defer) {226 getRes(defer);227 });228 });229};...

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eslint-plugin-promise_vx.x.x.js

Source:eslint-plugin-promise_vx.x.x.js Github

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1// flow-typed signature: cd888a19a61bc75c46972c5f589c09502// flow-typed version: <<STUB>>/eslint-plugin-promise_v^4.1.1/flow_v0.101.03/**4 * This is an autogenerated libdef stub for:5 *6 * 'eslint-plugin-promise'7 *8 * Fill this stub out by replacing all the `any` types.9 *10 * Once filled out, we encourage you to share your work with the11 * community by sending a pull request to:12 * https://github.com/flowtype/flow-typed13 */14declare module 'eslint-plugin-promise' {15 declare module.exports: any;16}17/**18 * We include stubs for each file inside this npm package in case you need to19 * require those files directly. Feel free to delete any files that aren't20 * needed.21 */22declare module 'eslint-plugin-promise/rules/always-return' {23 declare module.exports: any;24}25declare module 'eslint-plugin-promise/rules/avoid-new' {26 declare module.exports: any;27}28declare module 'eslint-plugin-promise/rules/catch-or-return' {29 declare module.exports: any;30}31declare module 'eslint-plugin-promise/rules/lib/get-docs-url' {32 declare module.exports: any;33}34declare module 'eslint-plugin-promise/rules/lib/has-promise-callback' {35 declare module.exports: any;36}37declare module 'eslint-plugin-promise/rules/lib/is-callback' {38 declare module.exports: any;39}40declare module 'eslint-plugin-promise/rules/lib/is-inside-callback' {41 declare module.exports: any;42}43declare module 'eslint-plugin-promise/rules/lib/is-inside-promise' {44 declare module.exports: any;45}46declare module 'eslint-plugin-promise/rules/lib/is-named-callback' {47 declare module.exports: any;48}49declare module 'eslint-plugin-promise/rules/lib/is-promise' {50 declare module.exports: any;51}52declare module 'eslint-plugin-promise/rules/lib/promise-statics' {53 declare module.exports: any;54}55declare module 'eslint-plugin-promise/rules/no-callback-in-promise' {56 declare module.exports: any;57}58declare module 'eslint-plugin-promise/rules/no-native' {59 declare module.exports: any;60}61declare module 'eslint-plugin-promise/rules/no-nesting' {62 declare module.exports: any;63}64declare module 'eslint-plugin-promise/rules/no-new-statics' {65 declare module.exports: any;66}67declare module 'eslint-plugin-promise/rules/no-promise-in-callback' {68 declare module.exports: any;69}70declare module 'eslint-plugin-promise/rules/no-return-in-finally' {71 declare module.exports: any;72}73declare module 'eslint-plugin-promise/rules/no-return-wrap' {74 declare module.exports: any;75}76declare module 'eslint-plugin-promise/rules/param-names' {77 declare module.exports: any;78}79declare module 'eslint-plugin-promise/rules/prefer-await-to-callbacks' {80 declare module.exports: any;81}82declare module 'eslint-plugin-promise/rules/prefer-await-to-then' {83 declare module.exports: any;84}85declare module 'eslint-plugin-promise/rules/valid-params' {86 declare module.exports: any;87}88// Filename aliases89declare module 'eslint-plugin-promise/index' {90 declare module.exports: $Exports<'eslint-plugin-promise'>;91}92declare module 'eslint-plugin-promise/index.js' {93 declare module.exports: $Exports<'eslint-plugin-promise'>;94}95declare module 'eslint-plugin-promise/rules/always-return.js' {96 declare module.exports: $Exports<'eslint-plugin-promise/rules/always-return'>;97}98declare module 'eslint-plugin-promise/rules/avoid-new.js' {99 declare module.exports: $Exports<'eslint-plugin-promise/rules/avoid-new'>;100}101declare module 'eslint-plugin-promise/rules/catch-or-return.js' {102 declare module.exports: $Exports<'eslint-plugin-promise/rules/catch-or-return'>;103}104declare module 'eslint-plugin-promise/rules/lib/get-docs-url.js' {105 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/get-docs-url'>;106}107declare module 'eslint-plugin-promise/rules/lib/has-promise-callback.js' {108 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/has-promise-callback'>;109}110declare module 'eslint-plugin-promise/rules/lib/is-callback.js' {111 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/is-callback'>;112}113declare module 'eslint-plugin-promise/rules/lib/is-inside-callback.js' {114 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/is-inside-callback'>;115}116declare module 'eslint-plugin-promise/rules/lib/is-inside-promise.js' {117 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/is-inside-promise'>;118}119declare module 'eslint-plugin-promise/rules/lib/is-named-callback.js' {120 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/is-named-callback'>;121}122declare module 'eslint-plugin-promise/rules/lib/is-promise.js' {123 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/is-promise'>;124}125declare module 'eslint-plugin-promise/rules/lib/promise-statics.js' {126 declare module.exports: $Exports<'eslint-plugin-promise/rules/lib/promise-statics'>;127}128declare module 'eslint-plugin-promise/rules/no-callback-in-promise.js' {129 declare module.exports: $Exports<'eslint-plugin-promise/rules/no-callback-in-promise'>;130}131declare module 'eslint-plugin-promise/rules/no-native.js' {132 declare module.exports: $Exports<'eslint-plugin-promise/rules/no-native'>;133}134declare module 'eslint-plugin-promise/rules/no-nesting.js' {135 declare module.exports: $Exports<'eslint-plugin-promise/rules/no-nesting'>;136}137declare module 'eslint-plugin-promise/rules/no-new-statics.js' {138 declare module.exports: $Exports<'eslint-plugin-promise/rules/no-new-statics'>;139}140declare module 'eslint-plugin-promise/rules/no-promise-in-callback.js' {141 declare module.exports: $Exports<'eslint-plugin-promise/rules/no-promise-in-callback'>;142}143declare module 'eslint-plugin-promise/rules/no-return-in-finally.js' {144 declare module.exports: $Exports<'eslint-plugin-promise/rules/no-return-in-finally'>;145}146declare module 'eslint-plugin-promise/rules/no-return-wrap.js' {147 declare module.exports: $Exports<'eslint-plugin-promise/rules/no-return-wrap'>;148}149declare module 'eslint-plugin-promise/rules/param-names.js' {150 declare module.exports: $Exports<'eslint-plugin-promise/rules/param-names'>;151}152declare module 'eslint-plugin-promise/rules/prefer-await-to-callbacks.js' {153 declare module.exports: $Exports<'eslint-plugin-promise/rules/prefer-await-to-callbacks'>;154}155declare module 'eslint-plugin-promise/rules/prefer-await-to-then.js' {156 declare module.exports: $Exports<'eslint-plugin-promise/rules/prefer-await-to-then'>;157}158declare module 'eslint-plugin-promise/rules/valid-params.js' {159 declare module.exports: $Exports<'eslint-plugin-promise/rules/valid-params'>;...

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Using AI Code Generation

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1const puppeteer = require('puppeteer');2const fs = require('fs');3const path = require('path');4(async () => {5 const browser = await puppeteer.launch();6 const page = await browser.newPage();7 await page.screenshot({path: 'example.png'});8 await browser.close();9})();10const puppeteer = require('puppeteer');11const fs = require('fs');12const path = require('path');13puppeteer.launch().then(async browser => {14 const page = await browser.newPage();15 await page.screenshot({path: 'example.png'});16 await browser.close();17});18const puppeteer = require('puppeteer');19const fs = require('fs');20const path = require('path');21(async () => {22 const browser = await puppeteer.launch();23 const page = await browser.newPage();24 await page.screenshot({path: 'example.png'});25 await browser.close();26})();27const puppeteer = require('puppeteer');28const fs = require('fs');29const path = require('path');30(async () => {31 const browser = await puppeteer.launch();32 const page = await browser.newPage();33 await page.screenshot({path: 'example.png'});34 await browser.close();35})();36const puppeteer = require('puppeteer');37const fs = require('fs');38const path = require('path');39(async () => {40 const browser = await puppeteer.launch();41 const page = await browser.newPage();42 await page.screenshot({path: 'example.png'});43 await browser.close();44})();45const puppeteer = require('puppeteer');46const fs = require('fs');47const path = require('path');

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Using AI Code Generation

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1const puppeteer = require('puppeteer');2const fs = require('fs');3(async () => {4 const browser = await puppeteer.launch();5 const page = await browser.newPage();6 await page.screenshot({path: 'example.png'});7 await browser.close();8})();

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Using AI Code Generation

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1const puppeteer = require('puppeteer');2async function main() {3 const browser = await puppeteer.launch({headless: false});4 const page = await browser.newPage();5 await page.screenshot({path: 'example.png'});6 await browser.close();7}8main();9const puppeteer = require('puppeteer');10const main = async () => {11 const browser = await puppeteer.launch({headless: false});12 const page = await browser.newPage();13 await page.screenshot({path: 'example.png'});14 await browser.close();15}16main();17const puppeteer = require('puppeteer');18const main = async () => {19 const browser = await puppeteer.launch({headless: false});20 const page = await browser.newPage();21 await page.screenshot({path: 'example.png'});22 await browser.close();23}24main();25const puppeteer = require('puppeteer');26const main = async () => {27 const browser = await puppeteer.launch({headless: false});28 const page = await browser.newPage();29 await page.screenshot({path: 'example.png'});30 await browser.close();31}32main();33const puppeteer = require('puppeteer');34const main = async () => {35 const browser = await puppeteer.launch({headless: false});36 const page = await browser.newPage();37 await page.screenshot({path: 'example.png'});38 await browser.close();39}40main();41const puppeteer = require('puppeteer');42const main = async () => {43 const browser = await puppeteer.launch({headless: false});44 const page = await browser.newPage();45 await page.screenshot({path: 'example.png

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1const puppeteer = require('puppeteer');2const devices = require('puppeteer/DeviceDescriptors');3const iPhone = devices['iPhone 6'];4const path = require('path');5const fs = require('fs');6const mkdirp = require('mkdirp');7const dir = './screenshots';8(async () => {9 const browser = await puppeteer.launch({headless: false});10 const page = await browser.newPage();11 await page.emulate(iPhone);12 await page.screenshot({path: 'example.png'});13 await browser.close();14})();15const puppeteer = require('puppeteer');16const devices = require('puppeteer/DeviceDescriptors');17const iPhone = devices['iPhone 6'];18const path = require('path');19const fs = require('fs');20const mkdirp = require('mkdirp');21const dir = './screenshots';22const run = async () => {23 const browser = await puppeteer.launch({headless: false});24 const page = await browser.newPage();25 await page.emulate(iPhone);26 await page.screenshot({path: 'example.png'});27 await browser.close();28};29run();30const puppeteer = require('puppeteer');31const devices = require('puppeteer/DeviceDescriptors');32const iPhone = devices['iPhone 6'];33const path = require('path');34const fs = require('fs');35const mkdirp = require('mkdirp');36const dir = './screenshots';37puppeteer.launch({headless: false})38 .then(browser => {39 return browser.newPage()40 .then(page => {41 return page.emulate(iPhone)42 .then(() => {43 .then(() => {44 return page.screenshot({path: 'example.png'})45 .then(() => {46 browser.close();47 })48 })49 })50 })51 })52 .catch(err => {53 console.log(err);54 });

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Using AI Code Generation

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1const puppeteer = require('puppeteer');2const fs = require('fs');3const path = require('path');4const url = require('url');5const util = require('util');6const readFile = util.promisify(fs.readFile);7const writeFile = util.promisify(fs.writeFile);8(async () => {9 const browser = await puppeteer.launch();10 const page = await browser.newPage();11 await page.goto(url);12 await page.screenshot({path: 'example.png'});13 await browser.close();14})();15const puppeteer = require('puppeteer');16const fs = require('fs');17const path = require('path');18const url = require('url');19const util = require('util');20const readFile = util.promisify(fs.readFile);21const writeFile = util.promisify(fs.writeFile);22const main = async () => {23 const browser = await puppeteer.launch();24 const page = await browser.newPage();25 await page.goto(url);26 await page.screenshot({path: 'example.png'});27 await browser.close();28};29main();

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Using AI Code Generation

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1const puppeteer = require('puppeteer');2const fs = require('fs');3const pdf = require('pdf-parse');4async function run() {5 const browser = await puppeteer.launch({6 });7 const page = await browser.newPage();8 await page.goto(url);9 await page.pdf({ path: 'google.pdf', format: 'A4' });10 await browser.close();11 console.log('Done');12}13run();14let dataBuffer = fs.readFileSync('google.pdf');15pdf(dataBuffer).then(function(data) {16 console.log(data.text);17});

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Automation Testing Tutorials

Learn to execute automation testing from scratch with LambdaTest Learning Hub. Right from setting up the prerequisites to run your first automation test, to following best practices and diving deeper into advanced test scenarios. LambdaTest Learning Hubs compile a list of step-by-step guides to help you be proficient with different test automation frameworks i.e. Selenium, Cypress, TestNG etc.

LambdaTest Learning Hubs:

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You could also refer to video tutorials over LambdaTest YouTube channel to get step by step demonstration from industry experts.

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