React中Firestore读取userRole报错：Cannot read properties of undefined

我尝试从Firebase Firestore的companies/{currentCompany}/users/{currentUserUID}路径下获取userRole字段，通过users集合里的companyCode做关联（这部分用console.log验证功能正常）。但第二个useEffect里总是报错：Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'userRole')，哪怕把请求里的数据换成硬编码值，错误还是一样。

const [currentUserUID, setCurrentUserUID] = useState(null)
const [currentUserCompanyCode, setCurrentUserCompanyCode] = useState(null)
const [currentUserCompanyRole, setCurrentUserCompanyCodeRole] = useState(null)
    
useEffect(() => {
  if (currentUserUID != null) {
    const docRefUser = doc(projectDb, "users", currentUserUID);
    getDoc (docRefUser).then((doc) => {
      setCurrentUserCompanyCode(doc.data().companyCode)
    })
  }
}, [currentUserUID]);

useEffect(() => {
  if (currentUserCompanyCode != null && currentUserUID != null) {
    const docRefCompany = doc(projectDb, "companies", currentUserCompanyCode, "users", currentUserUID);
    getDoc (docRefCompany).then((doc) => {
      setCurrentUserCompanyCodeRole(doc.data().userRole)
    })
  }
}, [currentUserCompanyCode, currentUserUID]);

console.log(currentUserCompanyCode)
console.log(currentUserCompanyRole)

• 截图1：展示Firestore数据库结构，companies集合下的文档包含users子集合
• 截图2：展示users集合中的用户文档，存在companyCode字段
• 截图3：展示浏览器控制台错误信息，显示报错内容Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'userRole')

内容的提问来源于stack exchange，提问作者Bas Mienis