feat(startWith): remove deprecated scheduler signature.

[benlesh]

• Removes deprecated scheduler signature
• Improves performance slightly
• Moves subscribeToArray closer to usage.

[demensky]

After the scheduler was removed, these comments became useless. Maybe we should remove them?

[demensky]

Are signatures with null and undefined still relevant?

[jakovljevic-mladen]

I think they aren't relevant anymore.

[demensky]

Here we exit the function as soon as subscriber.closed becomes true. Does it make sense to do something similar here?

[jakovljevic-mladen]

I think this is covered in the for loop. This part: && !subscriber.closed should ensure that.

[demensky]

It's just that in example, when subscriber.closed becomes true, then subscriber.complete() is not called, but in subscribeToArray it is called.

[jakovljevic-mladen]

If subscriber.complete() gets called, but subscription is already closed, it won't make any difference. Subscriber will not get complete notification multiple times, so this is OK I think.

[demensky]

Yes, I know that complete won't be notified several times. I just wanted to ask and suggest doing something like this:

Suggested change

	for (let i = 0; i < length && !subscriber.closed; i++) {
	subscriber.next(array[i]);
	}
	for (let i = 0; i < length; i++) {
	if (subscriber.closed) {
	return;
	}
	subscriber.next(array[i]);
	}

Nevermind, it's just my curiosity.

[demensky]

Suggested change

	for (let i = 0; i < length && !subscriber.closed; i++) {
	subscriber.next(array[i]);
	}
	for (let i = 0; i < length; i++) {
	if (subscriber.closed) {
	return;
	}
	subscriber.next(array[i]);
	}

I double-checked and made sure that if you do not return inside the loop, then onStoppedNotification will be called.

config.onStoppedNotification = (notification) => {
  console.log('onStoppedNotification', notification);
};

EMPTY.pipe(startWith(1, 2, 3), take(2)).subscribe();

[benlesh]

It is mildly more efficient, I suppose. A conditional followed by a return, rather than a conditional followed by a function call, a conditional and a return. It's not likely to make any performance difference though, I'd guess. Even at high-speed.

[demensky]

We are talking about a false positive onStoppedNotification call.

[demensky]

The difference is that return prevents subscriber.complete().

[demensky]

Just a reinsurance. Are you sure that these tests should be deleted? Isn't it enough just to remove testScheduler?

[benlesh]

Yeah, they're invalid tests now. This would test that it would start with 's' and then an instance of testScheduler. :)

[demensky]

Suggested change

	for (let i = 0; i < length && !subscriber.closed; i++) {
	subscriber.next(array[i]);
	}
	for (let i = 0; i < length; i++) {
	if (subscriber.closed) {
	return;
	}
	subscriber.next(array[i]);
	}

I double-checked and made sure that if you do not return inside the loop, then onStoppedNotification will be called.

config.onStoppedNotification = (notification) => {
  console.log('onStoppedNotification', notification);
};

EMPTY.pipe(startWith(1, 2, 3), take(2)).subscribe();