Node.js, Express: next 未定义，

Question

我收到Error: next is not defined 。 我不知道在哪个文件中出现此错误。

代码：

服务器.js

require("dotenv").config({
  path: "C:/Users/dogra/Documents/Web Development/Portfolio/FullStack/AdvanceAuth/.env",
});

const express = require("express");
const connectDB = require("./config/db");
const errorHandler = require("./middleware/errorHandler");

connectDB();

const app = express();

app.use(express.json());

app.use("/api/auth", require("./routes/authRoutes"));
app.use("/api/private", require("./routes/privateRoutes"));

app.use(errorHandler);

const PORT = process.env.PORT || 5000;

const server = app.listen(PORT, () => {
  console.log(`Server running on PORT: ${PORT}`);
});

process.on("unhandledRejection", (err, promise) => {
  console.log(`Logged Error: ${err.message}`);
  server.close(() => process.exit(1));
});

控制器

验证控制器.js

const User = require("../models/userModel");
const ErrorResponse = require("../utils/errorResponse");

exports.register = async (req, res, next) => {
  const { username, email, password } = req.body;

  try {
    const user = await User.create({
      username,
      email,
      password,
    });

    sendToken(user, 201, res);
  } catch (error) {
    next(error);
  }
};

exports.login = async (req, res, next) => {
  const { email, password } = req.body;

  if (!email || !password) {
    return next(new ErrorResponse("Please enter credentials properly", 400));
  }

  try {
    const user = await User.findOne({ email }).select("+password");

    if (!user) {
      return next(new ErrorResponse("Email not registered", 401));
    }

    const isMatch = await user.matchPasswords(password);
    if (!isMatch) {
      return next(new ErrorResponse("Invalid Password", 401));
    }

    sendToken(user, 200, res);
  } catch (error) {
    next();
  }
};

exports.forgotPassword = (req, res, next) => {
  res.send("ForgotPassword Route");
};

exports.resetPassword = (req, res, next) => {
  res.send("ResetPassword Route");
};

const sendToken = (user, statusCode, res) => {
  const token = user.getSignedJwtToken();
  res.status(statusCode).json({ success: true, token });
};

私有控制器.js

exports.private = (req, res, next) => {
  res.status(200).json({
    success: true,
    data: "You got access to the private data in this route",
  });
};

路线

authRoutes.js

const express = require("express");
const router = express.Router();

// controllers
const {
  register,
  login,
  forgotPassword,
  resetPassword,
} = require("../controllers/authControllers");

router.route("/register").post(register);
router.route("/login").post(login);
router.route("/forgotPassword").post(forgotPassword);
router.route("/resetPassword/:resetToken").put(resetPassword);

module.exports = router;

私有路由.js

const express = require("express");
const router = express.Router();
const { private } = require("../controllers/privateControllers");
const { protect } = require("../middleware/authMiddleware");

router.route("/").get(protect, private);

module.exports = router;

中间件

authMiddleware.js

const jwt = require("jsonwebtoken");
const User = require("../models/userModel");
const ErrorResponse = require("../utils/errorResponse");

exports.protect = async (req, res, next) => {
  let token;

  if (
    req.headers.authorization &&
    req.headers.authorization.startsWith("Bearer")
  ) {
    token = req.headers.authorization.split(" ")[1];
  }

  if (!token) {
    return next(
      new ErrorResponse("Not authorized to access to this route", 401)
    );
  }
  try {
    const decoded = jwt.verify(token, process.env.JWT_SECRET);
    const user = await User.findById(decoded.id);

    if (!user) {
      return next(new ErrorResponse("No User found with this id", 404));
    }

    req.user = user;
    next();
  } catch (error) {
    return next(new ErrorResponse("Not Authorized to access this route", 401));
  }
};

错误处理程序

const ErrorResponse = require("../utils/errorResponse");

const errorHandler = (err, req, res, next) => {
  let error = { ...err };

  error.message = err.message;

  if (err.code === 11000) {
    const message = `Duplicate Field value entered`;
    error = new ErrorResponse(message, 400);
  }

  if (err.name === "ValidationError") {
    const message = Object.values(err.errors).map((val) => val.message);
    error = new ErrorResponse(message, 400);
  }

  console.log(error.message);

  res.status(error.statusCode || 500).json({
    success: false,
    error: error.message || "Server Error",
  });
};

module.exports = errorHandler;

实用程序

错误响应.js

class ErrorResponse extends Error {
  constructor(message, statusCode) {
    super(message);
    this.statusCode = statusCode;
  }
}

module.exports = ErrorResponse;

楷模

用户模型.js

const mongoose = require("mongoose");
const bcrypt = require("bcryptjs");
const jwt = require("jsonwebtoken");

const UserSchema = new mongoose.Schema({
  username: {
    type: String,
    required: [true, "Please enter your username"],
  },
  email: {
    type: String,
    required: [true, "Please enter your email"],
    unique: true,
    lowercase: true,
    match: [
      /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/,
      ,
      "Please provide a valid email",
    ],
  },
  password: {
    type: String,
    required: [true, "Please enter a  valid password"],
    minlength: 8,
    select: false,
  },
  resetPasswordToken: String,
  resetPasswordExpired: Date,
});

// Hashing Password
UserSchema.pre("save", async function (next) {
  if (!this.isModified("password")) {
    next();
  }

  const salt = await bcrypt.genSalt(10);
  this.password = await bcrypt.hash(this.password, salt);
  next();
});

// Checking if password entered is correct or not
UserSchema.methods.matchPasswords = async function (password) {
  return await bcrypt.compare(password, this.password);
};

// Converting user data into JSON WEB TOKEN
UserSchema.methods.getSignedJwtToken = function () {
  return jwt.sign({ id: this._id }, process.env.JWT_SECRET, {
    expiresIn: process.env.JWT_EXPIRE,
  });
};

const User = mongoose.model("User", UserSchema);

module.exports = User;

抱歉，问题很长，但我真的不知道问题出在哪里。 我用谷歌搜索，发现当你没有定义它source时，我们得到next is not defined错误。 但是，我已经在我的所有控制器和中间件中定义了它。

Answer 1

问题dotenv在server.js中的dotenv路径中，因为我在新笔记本电脑中从 GitHub 克隆了我的项目，路径不同，我忘记更新路径。