RxJS asapScheduler stops working in 7.5.1 #6747
Description
Describe the bug
While trying to upgrade from RxJS6 to RxJS7 I noticed that sometimes our observables were not being executed. After debugging I found that at least asapScheduler did not always run the passed in callback function.
Expected behavior
asapScheduler should always run
Reproduction code
See the stackblitzSee the instructions in the stackblitz:
// To reproduce the issue (rxjs @ 7.5.1):
// 1. load this in stackblitz
// 2. observe that the logs up to '))) n 4' are printed
// 3. make a change to this file, note that it does not work (nothing runs)
// 4. reload the stackblitz page, you will see it work again
// To have it always work (rxjs @ 6.6.7):
// 1. load this in stackblitz
// 2. in the "Dependencies" on the left, enter [email protected]
// 2. observe that the logs up to '))) n 4' are printed
// 3. make a change to this file, note that it still works
In our own application, this stops working after ~135 calls to the asapScheduler. The same two calls were failing, but I could cause it to fail sooner if I used asapScheduler more frequently. I managed to get it to fail in stackblitz, but only while changing the stackblitz file. I'm not 100% sure this reproduces the issue in our own application, but the symptoms are the same, and in both 6.6.7 works
Reproduction URL
https://stackblitz.com/edit/rxjs-htf8tz?file=index.ts
Version
7.5.1
Environment
7.5.1 is causing the issue, but 6.6.7 works as expected
Additional context
Experienced in our corporate Angular 13 application