Recursive Type Example

deep-read-only

type DeepReadonlyObject<T> = { readonly [K in keyof T]: DeepReadonly<T[K]> };

type DeepReadonly<T> = T extends (infer E)[] ?
    ReadonlyArray<ReadonlyArray<DeepReadonlyObject<E>>> :
  T extends object ? DeepReadonlyObject<T> :
  T;