I intentionally use sync fs APIs for cli because it tend to run faster due to less async overhead.

As my understanding, the disk IO cannot be paralleled when the files are stored in the same disk.

We could setup benchmark to check if using async APIs actually speed up.

In my scenario, around 10 js files, the execution time has been reduced from 318ms to 88ms.

Are the files stored on SSD or rational harddisk in your case?

I'll also do some test when I have access to computer.

It seems your async version is faster than your sync version in most cases.
I tried to turn the current version into async version, the observation shows reversed difference.

I'll setup a more comprehensive benchmark before making decision.

Thanks for raising up the direction 🌱