Yarn, pnpm, webpack all have solutions for this. Great to see this becoming a standard. I have a project that is severely handicapped due to FS. Running 13k tests takes 40 minutes where a virtual file system that Node would just work with it would cut the run time to 3 minutes. I experimented with some hacks and decided to stay with slow but native FS solution.
What I really want is a way of swapping FS with VFS in a Node.js program harness. Something like
node --use-vfs --vfs-cache=BIG_JSON_FILE
The way to do this today is to do it outside of node. Using an overlay fs with the overlay being a ramfs. You can even chroot into it if you can't scope the paths you need to be just downstream from some directory. Or, just use docker.
making that work cross platform is pure pain
yes and no. Waiting 40mins for every test run is pure pain, platform specific ramfs type mounting is quite scriptable. Yes some devs might need to install a dependency, but its not a complex script.
What are the other OS? There's a bunch of solutions described on Wikipedia
https://en.wikipedia.org/wiki/List_of_RAM_drive_software