I'm looking forward to this. But it does amaze me how Microsoft with all it's power takes years to complete the port to a different language and bun does it in 7 days. Crazy times
Bun does zero work in relation to TypeScript's type system. Since it's a strict superset, it is "simply" stripping types to execute the resulting JavaScript. That is effectively what it boils down to.
TypeScript is the most complex type system in existence. I am unsurprised it is difficult to port, but I am still a bit surprised by the length of the project thus far.