Type Alias NestedKeyOf<ObjectType>

NestedKeyOf: ObjectType extends object
    ? {
        [Key in keyof ObjectType & (string | number)]: NonNullable<
            ObjectType[Key],
        > extends any[]
            ? `${Key}`
            : NonNullable<ObjectType[Key]> extends object
                ? `${Key}` | `${Key}.${NestedKeyOf<NonNullable<ObjectType[Key]>>}`
                : `${Key}`
    }[keyof ObjectType & (string | number)]
    : never