[soulnothing]

> I find the whole situation very unsatisfying. It is clear - when you actually use it heavily for a big project for a longer period - that a type system on top of Javascript is very difficult to maintain. LOTS of unsolved cases and issues. You definitely have to adapt and use only the subset of Javascript and the type system that works

This is spot on. I prefer type-driven development. But maintaining these typings is costly. Maintaining the definitions upstream is also difficult. GOing back to my redux / router example. There was one class they were going over again and again. Because it had a number of permutations and didn't meld well with a type system.