How long is compacting supposed to take?

Sure, but I can't guarantee it will happen again. It was a coding mistake on my part which lead to that, and when I managed to stop the code, half of the files in storage were gone. I could still delete the remaining ones via Bluetooth though. I don't remember exactly what I did anymore, but I'm pretty sure I did not write anything to storage, that's why I found it odd. So there is not necessarily a bug in espruino.