无效的钩子调用。 React.js

Question

Import useState from react, paste it to body function, but react tells me Wrong use hooks. Although another hook works like this.

import {getAuth} from 'firebase/auth';
import {useState} from 'react';

const useAuth = () => {

  const [state, setState] = useState(null); //wrong use

  const auth = getAuth();
  const getUserId = () => {
    return new Promise((resolve, reject) => {
      auth.onAuthStateChanged((user) => {
        if (user) {
          resolve(user.uid);
        } else {
          resolve(null);
        }
      });
    });
  };

  return {
    getUserId,
  };
};

export default useAuth;

Answer 1

Your returned getUserId is not a jsx. If your function is intended to be a react functionnal component then it is supposed to return a jsx. If not then you cannot use a react hook like useState.