In the original `Promise` impelmentation, zone.js follow the spec from
https://promisesaplus.com/#point-51.
```
const p1 = Promise.resolve(1);
const p2 = Promise.resolve(p1);
p1 === p2; // false
```
in this case, `p2` should be the same status with `p1` but they are
still different instances.
And for some edge case.
```
class MyPromise extends Promise {
constructor(sub) {
super((res) => res(null));
this.sub = sub;
}
then(onFufilled, onRejected) {
this.sub.then(onFufilled, onRejected);
}
}
const p1 = new Promise(setTimeout(res), 100);
const myP = new MyPromise(p1);
const r = await myP;
r === 1; // false
```
So in the above code, `myP` is not the same instance with `p1`,
and since `myP` is resolved in constructor, so `await myP` will
just pass without waiting for `p1`.
And in the current `tc39` spec here https://tc39.es/ecma262/multipage/control-abstraction-objects.html#sec-promise-resolve
`Promise.resolve(subP)` should return `subP`.
```
const p1 = Promise.resolve(1);
const p2 = Promise.resolve(p1);
p1 === p2; // true
```
So the above `MyPromise` can wait for the `p1` correctly.
PR Close#53423
* Adjusts tests to no longer rely on CommonJS features. Switches them to
ESM
* Updates test initialization files to not double-initialize Jasmine now
that bootstrap files are loaded after Jasmine. The `jasmine.boot`
setup was hacky from `rules_nodejs` and will break in the future
regardless if we e.g. use `rules_js` with actual unmodified `jasmine`.
PR Close#48521
The native promise implementation logs unhandled promise rejections after `onFinally`
has been called. We may rely on the `scheduledByFinally` argument, which is `false` by
default, to avoid creating a breaking change; this will also allow us to reduce the number of
changes. The `finally` function should not silence unhandled promise rejections, because
they're not silenced in any implementation. If the `scheduleResolveOrReject` is called within
the `finally` we won't clear unhandled rejections. We'll keep the same behaviour if the
`scheduleResolveOrReject` is called within the `then`.
PR Close#43206
PR Close#45449
Close#44913
The following case is not handled correctly by `zone.js`.
```
const delayedPromise = new Promise((resolve) => {
setTimeout(resolve, 1, 'timeout');
});
new Promise((resolve) => {
resolve(delayedPromise);
resolve('second call');
}).then(console.log);
```
It should output `timeout`, since the promise is resolved by the
1st resolve, the `second call` should be ignored.
So this is a bug that the original implementation not ensure the
`resolve` is only called once.
PR Close#45283
We must read `Symbol.species` safely because `this` may be anything. For instance, `this`
may be an object without a prototype (created through `Object.create(null)`); thus
`this.constructor` will be undefined. One of the use cases is SystemJS creating
prototype-less objects (modules) via `Object.create(null)`. The SystemJS creates an empty
object and copies promise properties into that object (within the `getOrCreateLoad`
function). The zone.js then checks if the resolved value has the `then` method and invokes
it with the `value` context. Otherwise, this will throw an error: `TypeError: Cannot read
properties of undefined (reading 'Symbol(Symbol.species)')`.
PR Close#45369
This PR updates Angular to compile with TypeScript 3.6 while retaining
compatibility with TS3.5. We achieve this by inserting several `as any`
casts for compatiblity around `ts.CompilerHost` APIs.
PR Close#32908
