They still didn't manage to put together a usable language. Just try to import your `Foo` class into `Bar` and your `Bar` class into `Foo`. BOOM! It will explode into your face. And this is just a basic thing which should work in a real language.

I will second this. I've seen some people choose FB's Flow as their type checker, but for me, I'm loving Typescript. It has minor problems when it has to use DefinitelyTyped and integrate with other frameworks, but those are minor in comparison to not having it.