lua-classy (https://github.com/siffiejoe/lua-classy) works like gem and is fast!
It's 10x larger than it needs to be, and seems to do a lot of unnecessary stuff. I would call this one hopelessly bloated and overengineered and recommend something like https://github.com/Yonaba/30log instead.
MoonScript is dead anyway. Check out yuescript instead: https://github.com/pigpigyyy/Yuescript