Some ideas about type shaping from other types, applied to form data handling/type-safety. Please, use Yup instead, makes much more sense. :)

FormDataUtil.ts

type FormFieldTuple<T> = { value: Required<T>, valid: boolean, message?: string };

type FormFieldData<T>
    = T extends undefined ? FormFieldTuple<T> | undefined
    : FormFieldTuple<T>
    ;

type FormFields<F, K extends keyof F = keyof F> = { [KK in K]:
    F[KK] extends object ? FormFields<F[KK]> : FormFieldData<F[KK]>
};

type FormField<F, K extends keyof F, T = never> = { [KK in K]:
    [T] extends [never]
    ? F[KK] extends object ? FormFields<F[KK]> : FormFieldData<F[KK]>
    : T extends object ? T : never
};


interface User {
    id: number;
    login: string;
    loginCount?: number;
}

interface Person {
    id: number;
    user: User;
    name: string;
    lastName: string;
    phone: number;
}

type PersonFormData = FormFields<Person, "name" | "lastName">
    & FormField<Person, 'user', FormField<User, 'login' | 'loginCount'>>;

var a: PersonFormData = {
    lastName: { value: '', valid: false },
    name: { value: '', valid: false },
    user: {
        login: { value: '', valid: false }
    }
}