I occasionally do this for python-only projects or for Makefiles, but (especially in the latter case) it's quite fragile. I usually use libconfig for configura

I occasionally do this for python-only projects or for Makefiles, but (especially in the latter case) it's quite fragile. I usually use libconfig for configuration, which is better than json and yaml and has implementations in many languages (although I'm not aware of any javascript implementation).