Cleanly switch to real time and back again to fake time while testing about fake-timers

[fatso83]

I have a real hard understanding why you need this complicated setup. fake-timers allows you to resolve async timers and promises without resorting to all these hacks. Switching back and forth between fake timers and real timers is a big smell that something is off in the design. Try see if using the *Async versions of tick, runAll and runToLast fixes your issues (I would think so, as that's what is normally used when mixing timers and promises, i.e. micro and macro ticks).

[weshouman]

Thanks, using clock.tickAsync() was actually the solution for it.

And as for the setup complexity, this demo was a minimal snippet that only captures the issue of a larger scenario of HIL (Hardware in the loop) Simulation testing, in which real time can not be overlooked and still there's a desire of ticking the clock in the HIL test itself.

This gist shows the demo with the *Async you mentioned as part of a HIL test demo.