`Unmasked` utility for GraphQL fragments

Unmasked.ts

type Decr = [never, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9];

type Obj = Record<string, unknown>;

type Prettify<T> = {
  [K in keyof T]: T[K];
} & NonNullable<unknown>;

type ValuesOf<T> = T[keyof T];

// eslint-disable-next-line @typescript-eslint/no-explicit-any
type UnionToIntersection<U> = (U extends any ? (k: U) => void : never) extends (
  k: infer I
) => void
  ? I
  : never;

export type Unmasked<TFrag, TDepth extends number = 9> = TDepth extends 0
  ? TFrag
  : FlattenedRefs<TFrag, TDepth> extends infer TFlattened
  ? {
      [TField in keyof TFlattened]: TFlattened[TField] extends
        | Obj
        | null
        | undefined
        ? Unmasked<TFlattened[TField], Decr[TDepth]>
        : TFlattened[TField] extends Array<infer TElement>
        ? Array<Unmasked<TElement, Decr[TDepth]>>
        : TFlattened[TField];
    }
  : never;

type FlattenedRefs<TFrag, TDepth extends number> = TFrag extends {
  " $fragmentRefs"?: infer TFragRefs;
}
  ? FlattenedRefs<
      Prettify<
        Omit<TFrag, " $fragmentRefs" | " $fragmentName"> &
          Omit<
            UnionToIntersection<ValuesOf<NonNullable<TFragRefs>>>,
            " $fragmentName"
          >
      >,
      TDepth
    >
  : TFrag;