问Javascript:在函数调用中传递有效参数，其中一个参数未定义

EN

export const SaveLanguageToDb = (uid, user, lang) => {
  console.log('in function:', uid, user)
  database.ref(`users/${uid}`).update({ currentLanguage: lang, ...user })
  .then(() => {
    return
  })
  .catch(e => { console.log('Error:', e) })
}

import React from 'react'
import { connect } from 'react-redux'
import en from '../../../public/images/United_Kingdom.png'
import pl from '../../../public/images/Poland.png'
import { SaveLanguageToDb } from '../../actions/user'
import { setLocale, } from 'react-redux-i18n'

export const LingoFlags = ({ uid, user, SaveLanguageToDb, setLocale }) => {
  console.log('before call:', uid, user)
  return (
  <div>
    <button
      className="button button--link"  
      onClick={() => {
        setLocale('en')
        SaveLanguageToDb(uid, user, 'en')
      }}
    >
      <img src={en} alt="en" />
    </button>
    <button
      className="button button--link"  
      onClick={() => {
        console.log('onClick:', uid, user)
        setLocale('pl')
        SaveLanguageToDb(uid, user, 'pl')
      }}
    >
      <img src={pl} alt="pl" />
    </button>
  </div>
)}

const matchStateToProps = (state) => ({
  uid: state.auth.uid,
  user: state.user,
})

const mapDispatchToProps = (dispatch) => ({
  SaveLanguageToDb: (lang) => dispatch(SaveLanguageToDb(lang)),
  setLocale: (lang) => dispatch(setLocale(lang))
}) 

export default connect(matchStateToProps, mapDispatchToProps)(LingoFlags)