> It's also a mess that does not have a spec. Even if you somehow manage to make a type checker that implements most of the features, there's no way to ensure i

> It's also a mess that does not have a spec. Even if you somehow manage to make a type checker that implements most of the features, there's no way to ensure it has 1 to 1 parity with TypeScript. Plus that parity can be broken at any point. You need a test suit for this not a spec.