I tried to refactor a big code base without these special helper types, it was a massive amount of duplication, to the point I just copy paste it or just aggreg

I tried to refactor a big code base without these special helper types, it was a massive amount of duplication, to the point I just copy paste it or just aggregate it into one folder and making it leak everywhere on my layers. The type and interface is just because they are structural typing. It's attempting to stay faithful to JavaScript after all. Without that then the intuition breaks and not consistent.