You can have that with Mypy and friends in Python, and Typescript in the JS world. The problem is that older libraries often don't utilise that type safety very well because their API wasn't designed for it.
The library in the original post is essentially a Javascript library, but it's one designed so that if you use it with Typescript, it provides that type safety.
The library in the original post is essentially a Javascript library, but it's one designed so that if you use it with Typescript, it provides that type safety.