| > I don't think that example would compile in TS either (not 100% confident though). I believe that code does compile by default. If you turn on the strict flag, that exact code wouldn't compile. BUT, if you wrote a class method instead of a top-level function in the above snippet, it STILL would compile. > The "issue" with TS is that everything type related completely disappears after the build step and that needs to be kept in mind in development. Some developers struggle with that, especially at the boundaries to external APIs/libs/whatever. I agree that a lot of devs struggle with that, but that's not really relevant to the type system being sound, and has nothing to do with the example I wrote. It can be proven to be incorrect at compile-time, so the compiler should reject it. In fact, most of the "hardcore" statically typed languages you hear about have full type-erasure: Haskell, Rust, ML, etc. Yet, they have reputations for very strong and strict static type systems. None of those languages would let the above garbage compile. |