在firebase和Expo中重置密碼時如何檢查當前密碼？

您可以使用reauthenticateWithCredential()驗證用戶密碼，然后使用updatePassword()更新密碼：

import { getAuth, reauthenticateWithCredential, EmailAuthProvider } from "firebase/auth";

const auth = getAuth();

const resetUserPassword = async () => {
  const user = auth.currentUser;

  const cred = EmailAuthProvider.credential(user.email, "[USER_PASSWORD]");

  try {
    await reauthenticateWithCredential(user, cred)
   
    // User entered correct credentials
    // Update password
    await updatePassword(auth.currentUser, "[NEW_PASSWORD]");
  } catch (e) {
    console.log(e.code, e.message)
    // Could be incorrect credentials
  }
} 

更新密碼需要最近登錄re-authentication，如果用戶長時間登錄，則需要re-authentication。