angular-docs-cn/packages/zone.js/lib/common/promise.ts

511 lines
18 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
Zone.__load_patch('ZoneAwarePromise', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
const ObjectGetOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
const ObjectDefineProperty = Object.defineProperty;
function readableObjectToString(obj: any) {
if (obj && obj.toString === Object.prototype.toString) {
const className = obj.constructor && obj.constructor.name;
return (className ? className : '') + ': ' + JSON.stringify(obj);
}
return obj ? obj.toString() : Object.prototype.toString.call(obj);
}
const __symbol__ = api.symbol;
const _uncaughtPromiseErrors: UncaughtPromiseError[] = [];
const symbolPromise = __symbol__('Promise');
const symbolThen = __symbol__('then');
const creationTrace = '__creationTrace__';
api.onUnhandledError = (e: any) => {
if (api.showUncaughtError()) {
const rejection = e && e.rejection;
if (rejection) {
console.error(
'Unhandled Promise rejection:',
rejection instanceof Error ? rejection.message : rejection, '; Zone:',
(<Zone>e.zone).name, '; Task:', e.task && (<Task>e.task).source, '; Value:', rejection,
rejection instanceof Error ? rejection.stack : undefined);
} else {
console.error(e);
}
}
};
api.microtaskDrainDone = () => {
while (_uncaughtPromiseErrors.length) {
while (_uncaughtPromiseErrors.length) {
const uncaughtPromiseError: UncaughtPromiseError = _uncaughtPromiseErrors.shift() !;
try {
uncaughtPromiseError.zone.runGuarded(() => { throw uncaughtPromiseError; });
} catch (error) {
handleUnhandledRejection(error);
}
}
}
};
const UNHANDLED_PROMISE_REJECTION_HANDLER_SYMBOL = __symbol__('unhandledPromiseRejectionHandler');
function handleUnhandledRejection(this: unknown, e: any) {
api.onUnhandledError(e);
try {
const handler = (Zone as any)[UNHANDLED_PROMISE_REJECTION_HANDLER_SYMBOL];
if (handler && typeof handler === 'function') {
handler.call(this, e);
}
} catch (err) {
}
}
function isThenable(value: any): boolean { return value && value.then; }
function forwardResolution(value: any): any { return value; }
function forwardRejection(rejection: any): any { return ZoneAwarePromise.reject(rejection); }
const symbolState: string = __symbol__('state');
const symbolValue: string = __symbol__('value');
const symbolFinally: string = __symbol__('finally');
const symbolParentPromiseValue: string = __symbol__('parentPromiseValue');
const symbolParentPromiseState: string = __symbol__('parentPromiseState');
const source: string = 'Promise.then';
const UNRESOLVED: null = null;
const RESOLVED = true;
const REJECTED = false;
const REJECTED_NO_CATCH = 0;
function makeResolver(promise: ZoneAwarePromise<any>, state: boolean): (value: any) => void {
return (v) => {
try {
resolvePromise(promise, state, v);
} catch (err) {
resolvePromise(promise, false, err);
}
// Do not return value or you will break the Promise spec.
};
}
const once = function() {
let wasCalled = false;
return function wrapper(wrappedFunction: Function) {
return function() {
if (wasCalled) {
return;
}
wasCalled = true;
wrappedFunction.apply(null, arguments);
};
};
};
const TYPE_ERROR = 'Promise resolved with itself';
const CURRENT_TASK_TRACE_SYMBOL = __symbol__('currentTaskTrace');
// Promise Resolution
function resolvePromise(
promise: ZoneAwarePromise<any>, state: boolean, value: any): ZoneAwarePromise<any> {
const onceWrapper = once();
if (promise === value) {
throw new TypeError(TYPE_ERROR);
}
if ((promise as any)[symbolState] === UNRESOLVED) {
// should only get value.then once based on promise spec.
let then: any = null;
try {
if (typeof value === 'object' || typeof value === 'function') {
then = value && value.then;
}
} catch (err) {
onceWrapper(() => { resolvePromise(promise, false, err); })();
return promise;
}
// if (value instanceof ZoneAwarePromise) {
if (state !== REJECTED && value instanceof ZoneAwarePromise &&
value.hasOwnProperty(symbolState) && value.hasOwnProperty(symbolValue) &&
(value as any)[symbolState] !== UNRESOLVED) {
clearRejectedNoCatch(<Promise<any>>value as any);
resolvePromise(promise, (value as any)[symbolState], (value as any)[symbolValue]);
} else if (state !== REJECTED && typeof then === 'function') {
try {
then.call(
value, onceWrapper(makeResolver(promise, state)),
onceWrapper(makeResolver(promise, false)));
} catch (err) {
onceWrapper(() => { resolvePromise(promise, false, err); })();
}
} else {
(promise as any)[symbolState] = state;
const queue = (promise as any)[symbolValue];
(promise as any)[symbolValue] = value;
if ((promise as any)[symbolFinally] === symbolFinally) {
// the promise is generated by Promise.prototype.finally
if (state === RESOLVED) {
// the state is resolved, should ignore the value
// and use parent promise value
(promise as any)[symbolState] = (promise as any)[symbolParentPromiseState];
(promise as any)[symbolValue] = (promise as any)[symbolParentPromiseValue];
}
}
// record task information in value when error occurs, so we can
// do some additional work such as render longStackTrace
if (state === REJECTED && value instanceof Error) {
// check if longStackTraceZone is here
const trace = Zone.currentTask && Zone.currentTask.data &&
(Zone.currentTask.data as any)[creationTrace];
if (trace) {
// only keep the long stack trace into error when in longStackTraceZone
ObjectDefineProperty(
value, CURRENT_TASK_TRACE_SYMBOL,
{configurable: true, enumerable: false, writable: true, value: trace});
}
}
for (let i = 0; i < queue.length;) {
scheduleResolveOrReject(promise, queue[i++], queue[i++], queue[i++], queue[i++]);
}
if (queue.length == 0 && state == REJECTED) {
(promise as any)[symbolState] = REJECTED_NO_CATCH;
try {
// try to print more readable error log
throw new Error(
'Uncaught (in promise): ' + readableObjectToString(value) +
(value && value.stack ? '\n' + value.stack : ''));
} catch (err) {
const error: UncaughtPromiseError = err;
error.rejection = value;
error.promise = promise;
error.zone = Zone.current;
error.task = Zone.currentTask !;
_uncaughtPromiseErrors.push(error);
api.scheduleMicroTask(); // to make sure that it is running
}
}
}
}
// Resolving an already resolved promise is a noop.
return promise;
}
const REJECTION_HANDLED_HANDLER = __symbol__('rejectionHandledHandler');
function clearRejectedNoCatch(this: unknown, promise: ZoneAwarePromise<any>): void {
if ((promise as any)[symbolState] === REJECTED_NO_CATCH) {
// if the promise is rejected no catch status
// and queue.length > 0, means there is a error handler
// here to handle the rejected promise, we should trigger
// windows.rejectionhandled eventHandler or nodejs rejectionHandled
// eventHandler
try {
const handler = (Zone as any)[REJECTION_HANDLED_HANDLER];
if (handler && typeof handler === 'function') {
handler.call(this, {rejection: (promise as any)[symbolValue], promise: promise});
}
} catch (err) {
}
(promise as any)[symbolState] = REJECTED;
for (let i = 0; i < _uncaughtPromiseErrors.length; i++) {
if (promise === _uncaughtPromiseErrors[i].promise) {
_uncaughtPromiseErrors.splice(i, 1);
}
}
}
}
function scheduleResolveOrReject<R, U1, U2>(
promise: ZoneAwarePromise<any>, zone: AmbientZone, chainPromise: ZoneAwarePromise<any>,
onFulfilled?: ((value: R) => U1) | null | undefined,
onRejected?: ((error: any) => U2) | null | undefined): void {
clearRejectedNoCatch(promise);
const promiseState = (promise as any)[symbolState];
const delegate = promiseState ?
(typeof onFulfilled === 'function') ? onFulfilled : forwardResolution :
(typeof onRejected === 'function') ? onRejected : forwardRejection;
zone.scheduleMicroTask(source, () => {
try {
const parentPromiseValue = (promise as any)[symbolValue];
const isFinallyPromise =
!!chainPromise && symbolFinally === (chainPromise as any)[symbolFinally];
if (isFinallyPromise) {
// if the promise is generated from finally call, keep parent promise's state and value
(chainPromise as any)[symbolParentPromiseValue] = parentPromiseValue;
(chainPromise as any)[symbolParentPromiseState] = promiseState;
}
// should not pass value to finally callback
const value = zone.run(
delegate, undefined,
isFinallyPromise && delegate !== forwardRejection && delegate !== forwardResolution ?
[] :
[parentPromiseValue]);
resolvePromise(chainPromise, true, value);
} catch (error) {
// if error occurs, should always return this error
resolvePromise(chainPromise, false, error);
}
}, chainPromise as TaskData);
}
const ZONE_AWARE_PROMISE_TO_STRING = 'function ZoneAwarePromise() { [native code] }';
class ZoneAwarePromise<R> implements Promise<R> {
static toString() { return ZONE_AWARE_PROMISE_TO_STRING; }
static resolve<R>(value: R): Promise<R> {
return resolvePromise(<ZoneAwarePromise<R>>new this(null as any), RESOLVED, value);
}
static reject<U>(error: U): Promise<U> {
return resolvePromise(<ZoneAwarePromise<U>>new this(null as any), REJECTED, error);
}
static race<R>(values: PromiseLike<any>[]): Promise<R> {
let resolve: (v: any) => void;
let reject: (v: any) => void;
let promise: any = new this((res, rej) => {
resolve = res;
reject = rej;
});
function onResolve(value: any) { resolve(value); }
function onReject(error: any) { reject(error); }
for (let value of values) {
if (!isThenable(value)) {
value = this.resolve(value);
}
value.then(onResolve, onReject);
}
return promise;
}
static all<R>(values: any): Promise<R> { return ZoneAwarePromise.allWithCallback(values); }
static allSettled<R>(values: any): Promise<R> {
const P = this && this.prototype instanceof ZoneAwarePromise ? this : ZoneAwarePromise;
return P.allWithCallback(values, {
thenCallback: (value: any) => ({status: 'fulfilled', value}),
errorCallback: (err: any) => ({status: 'rejected', reason: err})
});
}
static allWithCallback<R>(values: any, callback?: {
thenCallback: (value: any) => any,
errorCallback: (err: any) => any
}): Promise<R> {
let resolve: (v: any) => void;
let reject: (v: any) => void;
let promise = new this<R>((res, rej) => {
resolve = res;
reject = rej;
});
// Start at 2 to prevent prematurely resolving if .then is called immediately.
let unresolvedCount = 2;
let valueIndex = 0;
const resolvedValues: any[] = [];
for (let value of values) {
if (!isThenable(value)) {
value = this.resolve(value);
}
const curValueIndex = valueIndex;
try {
value.then(
(value: any) => {
resolvedValues[curValueIndex] = callback ? callback.thenCallback(value) : value;
unresolvedCount--;
if (unresolvedCount === 0) {
resolve !(resolvedValues);
}
},
(err: any) => {
if (!callback) {
reject !(err);
} else {
resolvedValues[curValueIndex] = callback.errorCallback(err);
unresolvedCount--;
if (unresolvedCount === 0) {
resolve !(resolvedValues);
}
}
});
} catch (thenErr) {
reject !(thenErr);
}
unresolvedCount++;
valueIndex++;
}
// Make the unresolvedCount zero-based again.
unresolvedCount -= 2;
if (unresolvedCount === 0) {
resolve !(resolvedValues);
}
return promise;
}
constructor(
executor:
(resolve: (value?: R|PromiseLike<R>) => void, reject: (error?: any) => void) => void) {
const promise: ZoneAwarePromise<R> = this;
if (!(promise instanceof ZoneAwarePromise)) {
throw new Error('Must be an instanceof Promise.');
}
(promise as any)[symbolState] = UNRESOLVED;
(promise as any)[symbolValue] = []; // queue;
try {
executor && executor(makeResolver(promise, RESOLVED), makeResolver(promise, REJECTED));
} catch (error) {
resolvePromise(promise, false, error);
}
}
get[Symbol.toStringTag]() { return 'Promise' as any; }
then<TResult1 = R, TResult2 = never>(
onFulfilled?: ((value: R) => TResult1 | PromiseLike<TResult1>)|undefined|null,
onRejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>)|undefined|
null): Promise<TResult1|TResult2> {
const chainPromise: Promise<TResult1|TResult2> =
new (this.constructor as typeof ZoneAwarePromise)(null as any);
const zone = Zone.current;
if ((this as any)[symbolState] == UNRESOLVED) {
(<any[]>(this as any)[symbolValue]).push(zone, chainPromise, onFulfilled, onRejected);
} else {
scheduleResolveOrReject(this, zone, chainPromise as any, onFulfilled, onRejected);
}
return chainPromise;
}
catch<TResult = never>(onRejected?: ((reason: any) => TResult | PromiseLike<TResult>)|undefined|
null): Promise<R|TResult> {
return this.then(null, onRejected);
}
finally<U>(onFinally?: () => U | PromiseLike<U>): Promise<R> {
const chainPromise: Promise<R|never> =
new (this.constructor as typeof ZoneAwarePromise)(null as any);
(chainPromise as any)[symbolFinally] = symbolFinally;
const zone = Zone.current;
if ((this as any)[symbolState] == UNRESOLVED) {
(<any[]>(this as any)[symbolValue]).push(zone, chainPromise, onFinally, onFinally);
} else {
scheduleResolveOrReject(this, zone, chainPromise as any, onFinally, onFinally);
}
return chainPromise;
}
}
// Protect against aggressive optimizers dropping seemingly unused properties.
// E.g. Closure Compiler in advanced mode.
ZoneAwarePromise['resolve'] = ZoneAwarePromise.resolve;
ZoneAwarePromise['reject'] = ZoneAwarePromise.reject;
ZoneAwarePromise['race'] = ZoneAwarePromise.race;
ZoneAwarePromise['all'] = ZoneAwarePromise.all;
const NativePromise = global[symbolPromise] = global['Promise'];
const ZONE_AWARE_PROMISE = Zone.__symbol__('ZoneAwarePromise');
let desc = ObjectGetOwnPropertyDescriptor(global, 'Promise');
if (!desc || desc.configurable) {
desc && delete desc.writable;
desc && delete desc.value;
if (!desc) {
desc = {configurable: true, enumerable: true};
}
desc.get = function() {
// if we already set ZoneAwarePromise, use patched one
// otherwise return native one.
return global[ZONE_AWARE_PROMISE] ? global[ZONE_AWARE_PROMISE] : global[symbolPromise];
};
desc.set = function(NewNativePromise) {
if (NewNativePromise === ZoneAwarePromise) {
// if the NewNativePromise is ZoneAwarePromise
// save to global
global[ZONE_AWARE_PROMISE] = NewNativePromise;
} else {
// if the NewNativePromise is not ZoneAwarePromise
// for example: after load zone.js, some library just
// set es6-promise to global, if we set it to global
// directly, assertZonePatched will fail and angular
// will not loaded, so we just set the NewNativePromise
// to global[symbolPromise], so the result is just like
// we load ES6 Promise before zone.js
global[symbolPromise] = NewNativePromise;
if (!NewNativePromise.prototype[symbolThen]) {
patchThen(NewNativePromise);
}
api.setNativePromise(NewNativePromise);
}
};
ObjectDefineProperty(global, 'Promise', desc);
}
global['Promise'] = ZoneAwarePromise;
const symbolThenPatched = __symbol__('thenPatched');
function patchThen(Ctor: Function) {
const proto = Ctor.prototype;
const prop = ObjectGetOwnPropertyDescriptor(proto, 'then');
if (prop && (prop.writable === false || !prop.configurable)) {
// check Ctor.prototype.then propertyDescriptor is writable or not
// in meteor env, writable is false, we should ignore such case
return;
}
const originalThen = proto.then;
// Keep a reference to the original method.
proto[symbolThen] = originalThen;
Ctor.prototype.then = function(onResolve: any, onReject: any) {
const wrapped =
new ZoneAwarePromise((resolve, reject) => { originalThen.call(this, resolve, reject); });
return wrapped.then(onResolve, onReject);
};
(Ctor as any)[symbolThenPatched] = true;
}
api.patchThen = patchThen;
function zoneify(fn: Function) {
return function(this: unknown) {
let resultPromise = fn.apply(this, arguments);
if (resultPromise instanceof ZoneAwarePromise) {
return resultPromise;
}
let ctor = resultPromise.constructor;
if (!ctor[symbolThenPatched]) {
patchThen(ctor);
}
return resultPromise;
};
}
if (NativePromise) {
patchThen(NativePromise);
const fetch = global['fetch'];
if (typeof fetch == 'function') {
global[api.symbol('fetch')] = fetch;
global['fetch'] = zoneify(fetch);
}
}
// This is not part of public API, but it is useful for tests, so we expose it.
(Promise as any)[Zone.__symbol__('uncaughtPromiseErrors')] = _uncaughtPromiseErrors;
return ZoneAwarePromise;
});