The biggest WTF for me is you want to solve problem X. Great someone has written some code in a library to solve X. You want to understand it. Cool, let's look at the source. It uses source transpiler #2 of the big 4, bundler #1 of the big 5, ui library #33 of the big 50, and oh yeah it uses proxies to make everything return a promise so g'luck debugging that.