[Typescript] 51. Medium - Mutable

Implement the generic Mutable<T> which makes all properties in T mutable (not readonly).

For example

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

type MutableTodo = Mutable<Todo> // { title: string; description: string; completed: boolean; }

 

/* _____________ Your Code Here _____________ */

type Mutable<T extends object> = {
  -readonly [K in keyof T]: T[K]
}

/* _____________ Test Cases _____________ */
import type { Equal, Expect } from '@type-challenges/utils'

interface Todo1 {
  title: string
  description: string
  completed: boolean
  meta: {
    author: string
  }
}

type List = [1, 2, 3]

type cases = [
  Expect<Equal<Mutable<Readonly<Todo1>>, Todo1>>,
  Expect<Equal<Mutable<Readonly<List>>, List>>,
]

type errors = [
  // @ts-expect-error
  Mutable<'string'>,
  // @ts-expect-error
  Mutable<0>,
]