[Typescript] 46. Medium PickByType

From T, pick a set of properties whose type are assignable to U.

For Example

type OnlyBoolean = PickByType<{
  name: string
  count: number
  isReadonly: boolean
  isEnable: boolean
}, boolean> // { isReadonly: boolean; isEnable: boolean; }

/* _____________ Your Code Here _____________ */

type PickByType<T extends object, U> = {
  [Key in keyof T as T[Key] extends U ? Key: never]: T[Key]
}

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

interface Model {
  name: string
  count: number
  isReadonly: boolean
  isEnable: boolean
}

type cases = [
  Expect<Equal<PickByType<Model, boolean>, { isReadonly: boolean; isEnable: boolean }>>,
  Expect<Equal<PickByType<Model, string>, { name: string }>>,
  Expect<Equal<PickByType<Model, number>, { count: number }>>,
]