fetched data from firestore as initial value of useState it gives me udefined value

Question

I want to set the fetched data from firestore as initial value of useState but it gives me undefined value because I want to update user profile and I don't know the user edits or updates which property because I want to keep the other properties of the user the same, only change the edited one.

I've tried this code, but it gives me this error: Uncaught (in promise) FirebaseError: Function updateDoc() called with invalid data. Unsupported field value: undefined (found in field surname in document users/DQjpLaKYVgVuH9TeqNomIEyuMJB2)

import React, { useState, useEffect } from 'react';
import { useAuthState } from 'react-firebase-hooks/auth';
import { doc, onSnapshot, updateDoc } from "firebase/firestore";
import { auth, db } from '../../firebase';


export default function Form({ setEditForm }) {
  const [user, setUser] = useState([]);
  const [currentUser] = useAuthState(auth);
  
  // fetching user information from firestore
  useEffect(() => {
    const getUser = async () => {
      const docRef = await doc(db, 'users', currentUser.uid)
      try {
        await onSnapshot(docRef, (doc) => {
          setUser({
            ...doc.data(), id: doc.id
          })
        })

      } catch (e) {
        console.log(e)
      }

    }
    getUser()
  }, [])

  const [name, setName] = useState(user.firstName);
  const [surname, setSurname] = useState(user.surname);
    const [biography, setBiography] = useState(user.biography);
  const [location, setLocation] = useState(user.location);

  // updating user's profile
  const updateProfile = async (e) => {
    e.preventDefault();
    const docRef = doc(db, 'users', currentUser.uid);
    await updateDoc(docRef, {
      firstName: name,
      surname: surname,
      biography: biography,
      location: location
    })
  }

  console.log(user)
  return (
    <form
      onSubmit={updateProfile}
      className="flex flex-col w-4/6 lg:w-3/6"
    >
      <div className="lg:flex lg:flex-row lg:justify-between lg:gap-6">
        <div className="lg:flex lg:flex-col lg:w-1/2">
          <h2 className="text-left text-[#4699C2] font-bold py-2">Name: </h2>
          <div className="border border-gray-300 rounded-md">
            <input
              type="text"
              placeholder={name}
              value={name}
              onChange={(e) => setName(e.target.value)}
              className="w-full py-2 px-4 opacity-50 focus:opacity-100"
            />
          </div>
        </div>

        <div className="lg:flex lg:flex-col lg:w-1/2">
          <h2 className="text-left text-[#4699C2] font-bold py-2">Surname: </h2>
          <div className="border border-gray-300 rounded-md">
            <input
              type="text"
              placeholder={surname}
              value={surname}
              onChange={(e) => setSurname(e.target.value)}
              className="opacity-50 px-4 focus:opacity-100 w-full py-2"
            />
          </div>
        </div>
      </div>

      <h2 className="text-left text-[#4699C2] font-bold py-2">Biograhpy: </h2>
      <div className="border border-gray-300 rounded-md">
        <textarea
          onChange={(e) => setBiography(e.target.value)}
          className="opacity-50 px-4 focus:opacity-100 w-full py-4"
        >
          {biography}
        </textarea>
      </div>

      <h2 className="text-left text-[#4699C2] font-bold py-2">Location: </h2>
      <div className="border border-gray-300 rounded-md">
        <input
          placeholder={location}
          value={location}
          onChange={(e) => setLocation(e.target.value)}
          className="opacity-50 px-4 focus:opacity-100 w-full py-2"
        />
      </div>

      <div className="flex flex-row justify-center py-4">
        <input
          type="submit"
          value="SAVE"
          className="bg-[#4699C2] text-white fong-bold w-24 py-3 rounded-full mx-4 font-bold hover:bg-[#026FC2] hover:shadow-lg focus:bg-[#026FC2] focus:shadow-lg focus:outline-none focus:ring-0 active:bg-[#026FC2] active:shadow-lg transition duration-150 ease-in-out"
        />
        <input
          onClick={() => {
            setEditForm(false);
          }}
          type="reset"
          value="CANCEL"
          className="bg-[#4699C2] cursor-pointer lg:bg-white hover:bg-[#026FC2] hover:text-white hover:shadow-lg focus:bg-[#026FC2] focus:shadow-lg focus:outline-none focus:ring-0 focus:text-white active:bg-[#026FC2] active:shadow-lg transition duration-150 ease-in-out text-white lg:text-[#4699C2] lg:border lg:border-[#4699C2] fong-bold w-24 py-3 rounded-full font-bold"
        />
      </div>
    </form>
  );
}

Answer 1

Answering this as community wiki, As suggested by @yograjtandel, instead of storing the response in one single state, first declare all the states like name, biography, surname, etc... to null. then in useState set all the states ex. setName(doc.data().Name) .