11.ts

// TS playground link: https://tsplay.dev/advent-of-typescript-2023-11

// Protect the List
// [a conversation overhead two elves, Wunorse and Alabaster, at Santa's workshop on a monday morning after all the elves were forced to work all weekend]
//     [Wurnose] The world will not know peace until every consultant involved in pushing SOC2 is dead and in the ground.
//     [Alabaster] Rough weekend?
//     [Wurnose] Yes. And now I've just gotten word from the higher-ups that I have to make our entire codebase's types readonly. DEEP readonly.
//     [Alabaster] Ouch. But at least it'll be better because something something functional programming superiority something something..
//     [Wurnose] That's not the point. The point is that there IS NO POINT. They're saying this is a requirement of SOC2. This doesn't have the slightest thing to do with SOC2. It's literally security theater at this point. And we're the puppets.
//     [Alabaster] Let's try to use this as an excuse to port the codebase to Rust where everything's immutable by default.
//     [Wurnose] I already tried that. They said Rust is too new and untested. They're considering Go, though.
//     [Alabaster] Lol dafuq? Rust is older than Go by like 3 years. Ok. Sorry I asked. Let's implement DeepReadonly then!
// The API
// SantaListProtector takes in an arbitrary type as an input and modifies that type to be readonly. The trick here is that it must also work for any nested objects.

type SantaListProtector<T extends object> = {
    +readonly [Property in keyof T]:
        T[Property] extends () => void ? T[Property] : T[Property] extends object ? SantaListProtector<T[Property]> : T[Property]
};