fix: implement Symbol.specics of Promise (#34162)

Close #34105, #33989

PR Close #34162
This commit is contained in:
JiaLiPassion 2019-12-01 12:27:33 +09:00 committed by Miško Hevery
parent 6b1a47183d
commit 539d8f09e0
2 changed files with 26 additions and 6 deletions

View File

@ -256,6 +256,8 @@ Zone.__load_patch('ZoneAwarePromise', (global: any, Zone: ZoneType, api: _ZonePr
const ZONE_AWARE_PROMISE_TO_STRING = 'function ZoneAwarePromise() { [native code] }';
const noop = function() {};
class ZoneAwarePromise<R> implements Promise<R> {
static toString() { return ZONE_AWARE_PROMISE_TO_STRING; }
@ -374,12 +376,17 @@ Zone.__load_patch('ZoneAwarePromise', (global: any, Zone: ZoneType, api: _ZonePr
get[Symbol.toStringTag]() { return 'Promise' as any; }
get[Symbol.species]() { return ZoneAwarePromise; }
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);
let C = (this.constructor as any)[Symbol.species];
if (!C || typeof C !== 'function') {
C = ZoneAwarePromise;
}
const chainPromise: Promise<TResult1|TResult2> = new (C as typeof ZoneAwarePromise)(noop);
const zone = Zone.current;
if ((this as any)[symbolState] == UNRESOLVED) {
(<any[]>(this as any)[symbolValue]).push(zone, chainPromise, onFulfilled, onRejected);
@ -395,8 +402,11 @@ Zone.__load_patch('ZoneAwarePromise', (global: any, Zone: ZoneType, api: _ZonePr
}
finally<U>(onFinally?: () => U | PromiseLike<U>): Promise<R> {
const chainPromise: Promise<R|never> =
new (this.constructor as typeof ZoneAwarePromise)(null as any);
let C = (this.constructor as any)[Symbol.species];
if (!C || typeof C !== 'function') {
C = ZoneAwarePromise;
}
const chainPromise: Promise<R|never> = new (C as typeof ZoneAwarePromise)(noop);
(chainPromise as any)[symbolFinally] = symbolFinally;
const zone = Zone.current;
if ((this as any)[symbolState] == UNRESOLVED) {

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@ -103,11 +103,21 @@ describe(
}).toThrowError('Must be an instanceof Promise.');
});
xit('should allow subclassing', () => {
it('should allow subclassing with Promise.specices', () => {
class MyPromise extends Promise<any> {
constructor(fn: any) { super(fn); }
static get[Symbol.species]() { return MyPromise; }
}
expect(new MyPromise(null).then(() => null) instanceof MyPromise).toBe(true);
expect(new MyPromise(() => {}).then(() => null) instanceof MyPromise).toBe(true);
});
it('Promise.specices should return ZoneAwarePromise', () => {
const empty = function() {};
const promise = Promise.resolve(1);
const FakePromise = ((promise.constructor = {} as any) as any)[Symbol.species] = function(
exec: any) { exec(empty, empty); };
expect(promise.then(empty) instanceof FakePromise).toBe(true);
});
it('should intercept scheduling of resolution and then', (done) => {