956 - DeepPick

[BOCbMOU]

type UnionToIntersection<U> = 
  (U extends U ? (arg: U) => void : never) extends ((arg: infer I) => void) ? I : never

type DeepPick<T, K extends string> = UnionToIntersection<DeepPickUnion<T, K>>

type DeepPickUnion<T, K extends string> =
  K extends `${infer KFirst extends keyof T & string}.${infer KRest extends string}`
    ? { [Key in KFirst]: DeepPickUnion<T[Key], KRest> }
    : K extends keyof T ? { [Key in K]: T[Key] } : never