TypeError：无法解构“req.body”的属性“email”，因为它未定义。 （设置 MERN 身份验证）

Question

我对后端和 MERN 非常陌生。对于任何滥用白话的行为，我深表歉意。 我正在尝试设置一个基本的身份验证，使用 MERN 和 Insomnia 作为 REST API CLIENT。 正如我在脚本中编写的那样，使用 npm run dev 启动服务器运行良好。我还使用 nodemon、jwb、bcryptjs、mongoose 和 dotenv 作为依赖关系。

发布注册请求效果很好：Insomnia Screenshot 1

但是发布这样的登录请求：Insomnia Screenshot 2 在我的路由器中解构 req.body 时会导致错误，如下所示：TypeError: Cannot destructure property 'email' of 'req.body' as it is undefined. at C:\Users\mackm\Desktop\Folders 2\vscode_work\React Projects\AUTHMERN\routers\userRouter.js:65:13

server.js 文件：

const mongoose = require("mongoose");
const dotenv = require("dotenv");

dotenv.config();

//set up server

const app = express();
PORT = process.env.PORT || 5000;
app.listen(PORT, () => console.log(`Server started on port: ${PORT}`));

//reads header of requests, if so: parses the json text into object and puts into request.body
app.use(express.json());

// connect to mongodb server

mongoose.connect(
  process.env.MDB_CONNECT,
  {
    useNewUrlParser: true,
    useUnifiedTopology: true,
  },
  (err) => {
    if (err) console.error(err);
    console.log("Connected to MongoDB");
  }
);

//set up routes

app.use("/auth", require("./routers/userRouter"));

路由器/userRouter.js：

const User = require("../models/userModel");
const bcrypt = require("bcryptjs");
const jwt = require("jsonwebtoken");

//register

router.post("/register", async (req, res) => {
  try {
    const { email, password, passwordVerify } = req.body;

    //validation

    if (!email || !password || !passwordVerify)
      return res
        .status(400)
        .json({ errorMessage: "Please enter all required fields" });
    if (password.length < 6)
      return res
        .status(400)
        .json({ errorMessage: "Please enter password of 6 or more charac" });
    if (passwordVerify !== password)
      return res.status(400).json({ errorMessage: "Passwords have to match" });
    const existingUser = await User.findOne({ email: email });

    // Check for existing users

    if (existingUser) {
      return res.status(400).json({
        errorMessage: "An account with this email already exists.",
      });
    }

    // hash the password

    const salt = await bcrypt.genSalt();
    const passwordHash = await bcrypt.hash(password, salt);

    //save a new user account to the database
    const newUser = new User({
      email,
      passwordHash,
    });

    const savedUser = await newUser.save();
    //sign the token
    const token = jwt.sign(
      {
        user: savedUser._id,
      },
      process.env.JWT_SECRET
    );
    //send the token in an HTTP only cookie
    res.cookie("token", token, { httpOnly: true }).send();
  } catch (err) {
    console.error(err);
    res.status(500).send;
  }
});

// log in
router.post("/login", async (res, req) => {
  try {
    console.log("login initiated");
    const { email, password } = req.body;

    //validate
    if (!email || !password)
      return res
        .status(400)
        .json({ errorMessage: "Please enter all required fields" });
    const existingUser = await User.findOne({ email: email });
    //handle non existent account
    if (!existingUser)
      return res
        .status(401)
        .json({ errorMessage: "Incorrect email or password" });
    const passwordCorrect = await bcrypt.compare(
      password,
      existingUser.passwordHash
    );
    //match password
    if (!passwordCorrect)
      return res
        .status(401)
        .json({ errorMessage: "Incorrect email or password" });
    //sign token
    const token = jwt.sign(
      {
        user: existingUser._id,
      },
      process.env.JWT_SECRET
    );
    //send the token in an HTTP only cookie
    res.cookie("token", token, { httpOnly: true }).send();
  } catch (err) {
    console.error(err);
    res.status(500).send();
  }
});

module.exports = router;```

  

Answer 1

您可以使用 body-parser 模块轻松使用 req.body 及其属性

const bodyparser = require('body-parser');

/*assuming an express app is declared here*/
app.use(bodyparser.json());
app.use(bodyparser.urlencoded({extended: true}));

那么如果你使用req.body你会找到请求的内容。

Answer 2

问题解决了：

在 userRouter.js 中 不正确（原文）：

router.post("/login", async (res, req) => {

正确（固定）：

router.post("/login", async (req, res) => {

箭头函数的参数原本与预期代码相反