Type alias DeepPartial<T>

DeepPartial<T>: {
    [P in keyof T]?: T[P] extends (infer U)[]
        ? DeepPartial<U>[]
        : T[P] extends ReadonlyArray<infer U>
            ? ReadonlyArray<DeepPartial<U>>
            : DeepPartial<T[P]>
}

Same as Partial but goes deeper and makes Partial all its properties and sub-properties.