Have you tried Elm? I always found the default mutability of JavaScript to be somewhat hostile to immutable data structures. Elm is very different - but feels

Have you tried Elm? I always found the default mutability of JavaScript to be somewhat hostile to immutable data structures. Elm is very different - but feels very integrated and the functional nature of the language really makes a lot of things simple and easy to debug/test, while being able to still do react-style dom diffing.