Infinite loop in closed async actions

Describe the bug

AsyncAction uses setInterval for delays, likely due to the fact setTimeout is often throttled/less accurate.

So the flow seems to roughly be this:

• schedule(state, delay)
• setInterval is now created to fire in delay time
• delay time passes
• execute is called
• clearInterval is called (via the recycle method)

If the action is closed when we call schedule, nothing will happen as you can see here:

https://github.com/ReactiveX/rxjs/blob/630d2b009b5ae4e8f2a62d9740738c1ec317c2d5/src/internal/scheduler/AsyncAction.ts#L21-L23

However, if the action is closed while we're waiting for delay time to pass, we will hit this:

https://github.com/ReactiveX/rxjs/blob/630d2b009b5ae4e8f2a62d9740738c1ec317c2d5/src/internal/scheduler/AsyncAction.ts#L90-L92

This means we throw and never clear the interval.

The interval then continues to fire forever (since it is an interval after all, being used as if it were a timeout), throwing the same Error infinitely.

This shouldn't be possible anyway because closing the subscription should be done via unsubscribe, which will clear the interval. There's probably a separate bug or a problem on my end that results in this weird state happening. However, its probably still sensible to cover the inf loop purely from a logic point of view even if you think it shouldn't ever be hit.

Expected behavior

A few less infinite loops

Reproduction code

No response

Reproduction URL

No response

Version

latest (exists in 7 & 8)

Environment

No response

Additional context

No response

Start at src/internal/scheduler/AsyncAction.ts, especially the schedule and recycle paths linked in the report. Trace the closed-action path while its delay interval is active, then verify that the interval is cleared and the error is not emitted repeatedly using the scheduler's tests or a minimal reproduction.