type-challenges/questions/5-extreme-readonly-keys

Get Readonly Keys

by Anthony Fu @antfu

Implement a generic GetReadonlyKeys<T> that returns a union of the readonly keys of an Object.

For example

interface Todo {
  readonly title: string
  readonly description: string
  completed: boolean
}

type Keys = GetReadonlyKeys<Todo> // expected to be "title" | "description"