es.promise.js 14 KB

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  1. 'use strict';
  2. var $ = require('../internals/export');
  3. var IS_PURE = require('../internals/is-pure');
  4. var global = require('../internals/global');
  5. var getBuiltIn = require('../internals/get-built-in');
  6. var call = require('../internals/function-call');
  7. var NativePromise = require('../internals/native-promise-constructor');
  8. var redefine = require('../internals/redefine');
  9. var redefineAll = require('../internals/redefine-all');
  10. var setPrototypeOf = require('../internals/object-set-prototype-of');
  11. var setToStringTag = require('../internals/set-to-string-tag');
  12. var setSpecies = require('../internals/set-species');
  13. var aCallable = require('../internals/a-callable');
  14. var isCallable = require('../internals/is-callable');
  15. var isObject = require('../internals/is-object');
  16. var anInstance = require('../internals/an-instance');
  17. var inspectSource = require('../internals/inspect-source');
  18. var iterate = require('../internals/iterate');
  19. var checkCorrectnessOfIteration = require('../internals/check-correctness-of-iteration');
  20. var speciesConstructor = require('../internals/species-constructor');
  21. var task = require('../internals/task').set;
  22. var microtask = require('../internals/microtask');
  23. var promiseResolve = require('../internals/promise-resolve');
  24. var hostReportErrors = require('../internals/host-report-errors');
  25. var newPromiseCapabilityModule = require('../internals/new-promise-capability');
  26. var perform = require('../internals/perform');
  27. var InternalStateModule = require('../internals/internal-state');
  28. var isForced = require('../internals/is-forced');
  29. var wellKnownSymbol = require('../internals/well-known-symbol');
  30. var IS_BROWSER = require('../internals/engine-is-browser');
  31. var IS_NODE = require('../internals/engine-is-node');
  32. var V8_VERSION = require('../internals/engine-v8-version');
  33. var SPECIES = wellKnownSymbol('species');
  34. var PROMISE = 'Promise';
  35. var getInternalState = InternalStateModule.getterFor(PROMISE);
  36. var setInternalState = InternalStateModule.set;
  37. var getInternalPromiseState = InternalStateModule.getterFor(PROMISE);
  38. var NativePromisePrototype = NativePromise && NativePromise.prototype;
  39. var PromiseConstructor = NativePromise;
  40. var PromisePrototype = NativePromisePrototype;
  41. var TypeError = global.TypeError;
  42. var document = global.document;
  43. var process = global.process;
  44. var newPromiseCapability = newPromiseCapabilityModule.f;
  45. var newGenericPromiseCapability = newPromiseCapability;
  46. var DISPATCH_EVENT = !!(document && document.createEvent && global.dispatchEvent);
  47. var NATIVE_REJECTION_EVENT = isCallable(global.PromiseRejectionEvent);
  48. var UNHANDLED_REJECTION = 'unhandledrejection';
  49. var REJECTION_HANDLED = 'rejectionhandled';
  50. var PENDING = 0;
  51. var FULFILLED = 1;
  52. var REJECTED = 2;
  53. var HANDLED = 1;
  54. var UNHANDLED = 2;
  55. var SUBCLASSING = false;
  56. var Internal, OwnPromiseCapability, PromiseWrapper, nativeThen;
  57. var FORCED = isForced(PROMISE, function () {
  58. var PROMISE_CONSTRUCTOR_SOURCE = inspectSource(PromiseConstructor);
  59. var GLOBAL_CORE_JS_PROMISE = PROMISE_CONSTRUCTOR_SOURCE !== String(PromiseConstructor);
  60. // V8 6.6 (Node 10 and Chrome 66) have a bug with resolving custom thenables
  61. // https://bugs.chromium.org/p/chromium/issues/detail?id=830565
  62. // We can't detect it synchronously, so just check versions
  63. if (!GLOBAL_CORE_JS_PROMISE && V8_VERSION === 66) return true;
  64. // We need Promise#finally in the pure version for preventing prototype pollution
  65. if (IS_PURE && !PromisePrototype['finally']) return true;
  66. // We can't use @@species feature detection in V8 since it causes
  67. // deoptimization and performance degradation
  68. // https://github.com/zloirock/core-js/issues/679
  69. if (V8_VERSION >= 51 && /native code/.test(PROMISE_CONSTRUCTOR_SOURCE)) return false;
  70. // Detect correctness of subclassing with @@species support
  71. var promise = new PromiseConstructor(function (resolve) { resolve(1); });
  72. var FakePromise = function (exec) {
  73. exec(function () { /* empty */ }, function () { /* empty */ });
  74. };
  75. var constructor = promise.constructor = {};
  76. constructor[SPECIES] = FakePromise;
  77. SUBCLASSING = promise.then(function () { /* empty */ }) instanceof FakePromise;
  78. if (!SUBCLASSING) return true;
  79. // Unhandled rejections tracking support, NodeJS Promise without it fails @@species test
  80. return !GLOBAL_CORE_JS_PROMISE && IS_BROWSER && !NATIVE_REJECTION_EVENT;
  81. });
  82. var INCORRECT_ITERATION = FORCED || !checkCorrectnessOfIteration(function (iterable) {
  83. PromiseConstructor.all(iterable)['catch'](function () { /* empty */ });
  84. });
  85. // helpers
  86. var isThenable = function (it) {
  87. var then;
  88. return isObject(it) && isCallable(then = it.then) ? then : false;
  89. };
  90. var notify = function (state, isReject) {
  91. if (state.notified) return;
  92. state.notified = true;
  93. var chain = state.reactions;
  94. microtask(function () {
  95. var value = state.value;
  96. var ok = state.state == FULFILLED;
  97. var index = 0;
  98. // variable length - can't use forEach
  99. while (chain.length > index) {
  100. var reaction = chain[index++];
  101. var handler = ok ? reaction.ok : reaction.fail;
  102. var resolve = reaction.resolve;
  103. var reject = reaction.reject;
  104. var domain = reaction.domain;
  105. var result, then, exited;
  106. try {
  107. if (handler) {
  108. if (!ok) {
  109. if (state.rejection === UNHANDLED) onHandleUnhandled(state);
  110. state.rejection = HANDLED;
  111. }
  112. if (handler === true) result = value;
  113. else {
  114. if (domain) domain.enter();
  115. result = handler(value); // can throw
  116. if (domain) {
  117. domain.exit();
  118. exited = true;
  119. }
  120. }
  121. if (result === reaction.promise) {
  122. reject(TypeError('Promise-chain cycle'));
  123. } else if (then = isThenable(result)) {
  124. call(then, result, resolve, reject);
  125. } else resolve(result);
  126. } else reject(value);
  127. } catch (error) {
  128. if (domain && !exited) domain.exit();
  129. reject(error);
  130. }
  131. }
  132. state.reactions = [];
  133. state.notified = false;
  134. if (isReject && !state.rejection) onUnhandled(state);
  135. });
  136. };
  137. var dispatchEvent = function (name, promise, reason) {
  138. var event, handler;
  139. if (DISPATCH_EVENT) {
  140. event = document.createEvent('Event');
  141. event.promise = promise;
  142. event.reason = reason;
  143. event.initEvent(name, false, true);
  144. global.dispatchEvent(event);
  145. } else event = { promise: promise, reason: reason };
  146. if (!NATIVE_REJECTION_EVENT && (handler = global['on' + name])) handler(event);
  147. else if (name === UNHANDLED_REJECTION) hostReportErrors('Unhandled promise rejection', reason);
  148. };
  149. var onUnhandled = function (state) {
  150. call(task, global, function () {
  151. var promise = state.facade;
  152. var value = state.value;
  153. var IS_UNHANDLED = isUnhandled(state);
  154. var result;
  155. if (IS_UNHANDLED) {
  156. result = perform(function () {
  157. if (IS_NODE) {
  158. process.emit('unhandledRejection', value, promise);
  159. } else dispatchEvent(UNHANDLED_REJECTION, promise, value);
  160. });
  161. // Browsers should not trigger `rejectionHandled` event if it was handled here, NodeJS - should
  162. state.rejection = IS_NODE || isUnhandled(state) ? UNHANDLED : HANDLED;
  163. if (result.error) throw result.value;
  164. }
  165. });
  166. };
  167. var isUnhandled = function (state) {
  168. return state.rejection !== HANDLED && !state.parent;
  169. };
  170. var onHandleUnhandled = function (state) {
  171. call(task, global, function () {
  172. var promise = state.facade;
  173. if (IS_NODE) {
  174. process.emit('rejectionHandled', promise);
  175. } else dispatchEvent(REJECTION_HANDLED, promise, state.value);
  176. });
  177. };
  178. var bind = function (fn, state, unwrap) {
  179. return function (value) {
  180. fn(state, value, unwrap);
  181. };
  182. };
  183. var internalReject = function (state, value, unwrap) {
  184. if (state.done) return;
  185. state.done = true;
  186. if (unwrap) state = unwrap;
  187. state.value = value;
  188. state.state = REJECTED;
  189. notify(state, true);
  190. };
  191. var internalResolve = function (state, value, unwrap) {
  192. if (state.done) return;
  193. state.done = true;
  194. if (unwrap) state = unwrap;
  195. try {
  196. if (state.facade === value) throw TypeError("Promise can't be resolved itself");
  197. var then = isThenable(value);
  198. if (then) {
  199. microtask(function () {
  200. var wrapper = { done: false };
  201. try {
  202. call(then, value,
  203. bind(internalResolve, wrapper, state),
  204. bind(internalReject, wrapper, state)
  205. );
  206. } catch (error) {
  207. internalReject(wrapper, error, state);
  208. }
  209. });
  210. } else {
  211. state.value = value;
  212. state.state = FULFILLED;
  213. notify(state, false);
  214. }
  215. } catch (error) {
  216. internalReject({ done: false }, error, state);
  217. }
  218. };
  219. // constructor polyfill
  220. if (FORCED) {
  221. // 25.4.3.1 Promise(executor)
  222. PromiseConstructor = function Promise(executor) {
  223. anInstance(this, PromisePrototype);
  224. aCallable(executor);
  225. call(Internal, this);
  226. var state = getInternalState(this);
  227. try {
  228. executor(bind(internalResolve, state), bind(internalReject, state));
  229. } catch (error) {
  230. internalReject(state, error);
  231. }
  232. };
  233. PromisePrototype = PromiseConstructor.prototype;
  234. // eslint-disable-next-line no-unused-vars -- required for `.length`
  235. Internal = function Promise(executor) {
  236. setInternalState(this, {
  237. type: PROMISE,
  238. done: false,
  239. notified: false,
  240. parent: false,
  241. reactions: [],
  242. rejection: false,
  243. state: PENDING,
  244. value: undefined
  245. });
  246. };
  247. Internal.prototype = redefineAll(PromisePrototype, {
  248. // `Promise.prototype.then` method
  249. // https://tc39.es/ecma262/#sec-promise.prototype.then
  250. then: function then(onFulfilled, onRejected) {
  251. var state = getInternalPromiseState(this);
  252. var reactions = state.reactions;
  253. var reaction = newPromiseCapability(speciesConstructor(this, PromiseConstructor));
  254. reaction.ok = isCallable(onFulfilled) ? onFulfilled : true;
  255. reaction.fail = isCallable(onRejected) && onRejected;
  256. reaction.domain = IS_NODE ? process.domain : undefined;
  257. state.parent = true;
  258. reactions[reactions.length] = reaction;
  259. if (state.state != PENDING) notify(state, false);
  260. return reaction.promise;
  261. },
  262. // `Promise.prototype.catch` method
  263. // https://tc39.es/ecma262/#sec-promise.prototype.catch
  264. 'catch': function (onRejected) {
  265. return this.then(undefined, onRejected);
  266. }
  267. });
  268. OwnPromiseCapability = function () {
  269. var promise = new Internal();
  270. var state = getInternalState(promise);
  271. this.promise = promise;
  272. this.resolve = bind(internalResolve, state);
  273. this.reject = bind(internalReject, state);
  274. };
  275. newPromiseCapabilityModule.f = newPromiseCapability = function (C) {
  276. return C === PromiseConstructor || C === PromiseWrapper
  277. ? new OwnPromiseCapability(C)
  278. : newGenericPromiseCapability(C);
  279. };
  280. if (!IS_PURE && isCallable(NativePromise) && NativePromisePrototype !== Object.prototype) {
  281. nativeThen = NativePromisePrototype.then;
  282. if (!SUBCLASSING) {
  283. // make `Promise#then` return a polyfilled `Promise` for native promise-based APIs
  284. redefine(NativePromisePrototype, 'then', function then(onFulfilled, onRejected) {
  285. var that = this;
  286. return new PromiseConstructor(function (resolve, reject) {
  287. call(nativeThen, that, resolve, reject);
  288. }).then(onFulfilled, onRejected);
  289. // https://github.com/zloirock/core-js/issues/640
  290. }, { unsafe: true });
  291. // makes sure that native promise-based APIs `Promise#catch` properly works with patched `Promise#then`
  292. redefine(NativePromisePrototype, 'catch', PromisePrototype['catch'], { unsafe: true });
  293. }
  294. // make `.constructor === Promise` work for native promise-based APIs
  295. try {
  296. delete NativePromisePrototype.constructor;
  297. } catch (error) { /* empty */ }
  298. // make `instanceof Promise` work for native promise-based APIs
  299. if (setPrototypeOf) {
  300. setPrototypeOf(NativePromisePrototype, PromisePrototype);
  301. }
  302. }
  303. }
  304. $({ global: true, wrap: true, forced: FORCED }, {
  305. Promise: PromiseConstructor
  306. });
  307. setToStringTag(PromiseConstructor, PROMISE, false, true);
  308. setSpecies(PROMISE);
  309. PromiseWrapper = getBuiltIn(PROMISE);
  310. // statics
  311. $({ target: PROMISE, stat: true, forced: FORCED }, {
  312. // `Promise.reject` method
  313. // https://tc39.es/ecma262/#sec-promise.reject
  314. reject: function reject(r) {
  315. var capability = newPromiseCapability(this);
  316. call(capability.reject, undefined, r);
  317. return capability.promise;
  318. }
  319. });
  320. $({ target: PROMISE, stat: true, forced: IS_PURE || FORCED }, {
  321. // `Promise.resolve` method
  322. // https://tc39.es/ecma262/#sec-promise.resolve
  323. resolve: function resolve(x) {
  324. return promiseResolve(IS_PURE && this === PromiseWrapper ? PromiseConstructor : this, x);
  325. }
  326. });
  327. $({ target: PROMISE, stat: true, forced: INCORRECT_ITERATION }, {
  328. // `Promise.all` method
  329. // https://tc39.es/ecma262/#sec-promise.all
  330. all: function all(iterable) {
  331. var C = this;
  332. var capability = newPromiseCapability(C);
  333. var resolve = capability.resolve;
  334. var reject = capability.reject;
  335. var result = perform(function () {
  336. var $promiseResolve = aCallable(C.resolve);
  337. var values = [];
  338. var counter = 0;
  339. var remaining = 1;
  340. iterate(iterable, function (promise) {
  341. var index = counter++;
  342. var alreadyCalled = false;
  343. remaining++;
  344. call($promiseResolve, C, promise).then(function (value) {
  345. if (alreadyCalled) return;
  346. alreadyCalled = true;
  347. values[index] = value;
  348. --remaining || resolve(values);
  349. }, reject);
  350. });
  351. --remaining || resolve(values);
  352. });
  353. if (result.error) reject(result.value);
  354. return capability.promise;
  355. },
  356. // `Promise.race` method
  357. // https://tc39.es/ecma262/#sec-promise.race
  358. race: function race(iterable) {
  359. var C = this;
  360. var capability = newPromiseCapability(C);
  361. var reject = capability.reject;
  362. var result = perform(function () {
  363. var $promiseResolve = aCallable(C.resolve);
  364. iterate(iterable, function (promise) {
  365. call($promiseResolve, C, promise).then(capability.resolve, reject);
  366. });
  367. });
  368. if (result.error) reject(result.value);
  369. return capability.promise;
  370. }
  371. });