Type Alias UnwrapPayload<P>

UnwrapPayload: {} extends P
    ? unknown
    : {
        [K in keyof P]: P[K] extends { composites: infer C; scalars: infer S }[]
            ? (S & UnwrapPayload<C>)[]
            : P[K] extends { composites: infer C; scalars: infer S }
            | null
                ? S & UnwrapPayload<C> | Select<P[K], null>
                : never
    }