Readonly type under the hood in TypeScript

Second challenge is Readonly

Similarly to Pick, it's usually used when you need to declare the type which is based on another type. The values on the first layer are immutable, or readonly 🔒

Iteration over an object

As previously for Pick, we use Mapped Types for the iteration:

Make values readonly

To make first layer of properties immutable, we use readonly modifier and that's it ✅

Check out the solution in Playground ⭐️