mern-scaffold/applications/backend/controllers/authControllers.js

mern-scaffold is a CLI tool that helps you to quickly develop basic boilerplate code for your MERN app. You can generate boilerplate code for your Frontend or Backend. You can also generate them as a full stack project.

const CustomError = require("../utils/customError"); // Import the custom error class
const UserModel = require("../model/userModel"); // Import the user model
const HTTPSTATUSCODE = require("../utils/httpStatusCodes"); // Import the HTTP status codes
const { generateJwtToken } = require("../utils/tokens"); // Import the function to generate JWT tokens
const validator = require("validator").default; // Import the validator library
const bcrypt = require("bcrypt"); // Import the bcrypt library for password hashing

const signUpUser = async (req, res) => {
  // Extract the name, email, and password from the request body
  const { name, email, password } = req.body;

  if (!name.trim()) {
    throw new CustomError(
      HTTPSTATUSCODE.BAD_REQUEST,
      "Please provide your name"
    );
  }

  // Validate the input
  if (
    !validator.isEmail(email) // Check if the email is valid
  ) {
    // If any of the checks fail, throw a custom error
    throw new CustomError(
      HTTPSTATUSCODE.BAD_REQUEST,
      "Please provide a valid email address"
    );
  }

  if (!validator.isStrongPassword(password)) {
    throw new CustomError(
      HTTPSTATUSCODE.BAD_REQUEST,
      "Password must be at least 8 characters long and contain a number, an uppercase letter, and a special character"
    );
  }

  // Check if a user with the provided email already exists
  const user = await UserModel.findOne({ email });
  if (user) {
    // If a user with the same email exists, throw a custom error
    throw new CustomError(400, `An account with ${email} already exist`);
  }

  // Create a new user with the provided data
  const newUser = await UserModel.create({
    name,
    email,
    password,
  });

  // Generate a JWT access token for the user
  const accessToken = await generateJwtToken({
    userId: newUser._id, // Use the user's ID as the subject of the token
    name: newUser.name, // Include the user's name in the token payload
    email: newUser.email, // Include the user's email in the token payload
  });

  // Send the response with the user's information and the access token
  res
    .status(HTTPSTATUSCODE.CREATED) // Set the status code to 201 (Created)
    .json({ name: newUser.name, email: newUser.email, accessToken }); // Send the user's name, email, and the access token in the response body
};

const signIn = async (req, res) => {
  // Extract the email and password from the request body
  const { email, password } = req.body;

  // Validate the input
  if (!validator.isEmail(email) || !validator.isStrongPassword(password)) {
    // If any of the checks fail, throw a custom error
    throw new CustomError(
      HTTPSTATUSCODE.BAD_REQUEST,
      "Please provide a valid email address and password"
    );
  }

  // Find the user with the provided email
  const user = await UserModel.findOne({ email });

  // If the user does not exist, throw a custom error
  if (!user) {
    throw new CustomError(
      HTTPSTATUSCODE.BAD_REQUEST,

      `No account with ${email}`
    );
  }

  // Compare the provided password with the user's hashed password
  const passwordCorrect = await bcrypt.compare(password, user.password);

  // If the password is incorrect, throw a custom error
  if (!passwordCorrect) {
    throw new CustomError(
      HTTPSTATUSCODE.BAD_REQUEST,
      "Password or email is incorrect"
    );
  }

  // Generate a JWT access token for the user
  const accessToken = await generateJwtToken({
    userId: user._id, // Use the user's ID as the subject of the token
    name: user.name, // Include the user's name in the token payload
    email: user.email, // Include the user's email in the token payload
  });

  // Create a user info object to send in the response
  const userInfo = {
    name: user.name,
    userId: user._id,
  };

  // Send the response with the user's information and the access token
  res.status(200).json({ ...userInfo, accessToken }); // Send the user's name, user ID, and the access token in the response body
};

module.exports = {
  signUpUser,
  signIn,
};