Authentication( SignUp and Login ) with Express,MongoDB and Jwt.
Tags: webdev, javascript, beginners, tutorial
Published: 2024-02-15 14:52:11

In this article, I'll walk through the process of setting up user authentication using Express, MongoDB, and JSON Web Tokens (JWT). This will allow you to implement user signup, login, and protect routes that require authentication.
## Let's Dive Right In 😁😁

![Dive In](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/p10pgjzovsokbv5tw91q.gif)

## Prerequisites

Make sure you have Node.js installed on your machine. Additionally, create a new directory for your project and initialize it with the following dependencies:

```bash
npm init -y
npm install express mongoose dotenv jsonwebtoken bcrypt
```
> This process should look like this:
![cmd](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/azgonvueak5ffck10g1d.png)

> Create your main entry file, .env and .gitignore if you wish to push your code
```bash
touch index.js .env .gitignore
```
## Project Setup
1. We'll import our packages into `index.js` and setup our express server.
```javascript
const express = require('express');
const dotenv = require('dotenv');

dotenv.config();

const app = express();
const PORT = process.env.PORT || 3000;


app.use(express.json());

app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});
```
> Make sure your script is set in your package.json. Now when I do `npm run dev` on my terminal I should have `Server is running on port 5500`
> And do not forget to also declare your PORT in the .env file.

2. I would quickly 😋😋 add a root entry file
> Now my code looks like this
```javascript
const express = require('express');
const dotenv = require('dotenv');

dotenv.config();

const app = express();
const PORT = process.env.PORT || 3000;

app.use(express.json());

app.get('/', (req, res)=> {
    res.send('Welcome to Nodejs Authentication Tutorial')
})

app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});
```
3. I'll create a folder called `config` to hold my database file which I would call `database.js`
> Now I would configure my database, my `database.js` folder would look like this:
```javascript
const mongoose = require('mongoose');

exports.connectDb = async () => {
  try {
    await mongoose.connect(process.env.MONGODB_URI);
    console.log("MongoDB connection Established...");
  } catch (error) {
    console.error(error.message);
  }
}
```
4. I would import the database function into the `index.js` file and fire it.
> Your index.js file should look like this now
```javascript
const express = require("express");
const dotenv = require("dotenv");
const { connectDb } = require("./config/database");

dotenv.config();

const app = express();
const PORT = process.env.PORT || 3000;

// Iinitialized Database Configuration
connectDb();

app.use(express.json());

// Root Entry 
app.get("/", (req, res) => {
  res.send("Welcome to Nodejs Authentication Tutorial");
});

// Listened to the PORT
app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});
```
5. Let's define our user Schema For Mongodb, we'll be accepting just two fields `username and password`
> We'll create a folder called `models` and a file called `userModels.js`
> My `userModels.js` file looks like this now

```javascript
const mongoose = require('mongoose');


const userSchema = new mongoose.Schema({
    username: { type: String, required: true },
    password: { type: String, required: true }
});

const User = mongoose.model('User', userSchema);

module.exports = User;
```

![Whew](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/x5mxe1ajl8o6jfhmgefa.gif)

6. Now let's create a folder called `controller` and a file called `userController.js` 
> Now Your `userController.js` should look like this
```javascript
const bcrypt = require("bcrypt");
const jwt = require("jsonwebtoken");
const User  = require("../models/userModels");

exports.signUp = async (req, res) => {
  try {
    const { username, password } = req.body;

    // Check If The Input Fields are Valid
    if (!username || !password) {
      return res
        .status(400)
        .json({ message: "Please Input Username and Password" });
    }

    // Check If User Exists In The Database
    const existingUser = await User.findOne({ username });

    if (existingUser) {
      return res.status(400).json({ message: "User Already Exists" });
    }

    // Hash The User's Password
    const saltRounds = 10;
    const hashedPassword = await bcrypt.hash(password, saltRounds);

    // Save The User To The Database
    const newUser = new User({
      username,
      password: hashedPassword,
    });

    await newUser.save();

    return res
      .status(201)
      .json({ message: "User Created Successfully", newUser });
  } catch (error) {
    console.log(error.message);
    return res.status(500).json({ message: "Error creating user" });
  }
};

```
7. Now we create our `routes` folder and `user.Routes.js` file
> Now the `user.Routes.js` file should look like this;
```javascript
const express = require('express');
const { signUp } = require('../controller/userController');
const router = express.Router();

router.post('/signup', signUp);

module.exports = router;
```
8. We'll import our Router into the `index.js` file 
> We'll add these two lines of code to our `index.js` file
```javascript
const userRouter = require("./routes/user.Routes");
app.use("/api/v1/user", userRouter);
```
> Now `index.js` Should look like this
```javascript
const express = require("express");
const dotenv = require("dotenv");
const { connectDb } = require("./config/database");
const userRouter = require("./routes/user.Routes");

dotenv.config();

const app = express();
const PORT = process.env.PORT || 3000;

// Iinitialized Database Configuration
connectDb();

app.use(express.json());

// Import The User Route
app.use("/api/v1/user", userRouter);

// Root Entry
app.get("/", (req, res) => {
  res.send("Welcome to Nodejs Authentication Tutorial");
});

// Listened to the PORT
app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});
```
> Now Let's Test, I would be using thunder client 
You test with this route `http://localhost:5500/api/v1/user/signup`

![Testing Signup](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/usdtnrin2arzofq9e0bs.png)
> You can install MongoDB compass to also check 

![Database Check](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/nlvjf237gzeqiyzmrxql.png)

## Now We Can Try Login 
> Right inside your `userController.js` we'll write the lines of code for login. And That Should Look like this
```Javascript
exports.login = async (req, res) => {
  try {
    const { username, password } = req.body;

    // Check If The Input Fields are Valid
    if (!username || !password) {
      return res
        .status(400)
        .json({ message: "Please Input Username and Password" });
    }

    // Check If User Exists In The Database
    const user = await User.findOne({ username });

    if (!user) {
      return res.status(401).json({ message: "Invalid username or password" });
    }

    // Compare Passwords
    const passwordMatch = await bcrypt.compare(password, user.password);

    if (!passwordMatch) {
      return res.status(401).json({ message: "Invalid username or password" });
    }

    // Generate JWT Token
    const token = jwt.sign(
      { userId: user._id, username: user.username },
      process.env.SECRET_KEY || "1234!@#%<{*&)",
      { expiresIn: "1h" }
    );

    return res
      .status(200)
      .json({ message: "Login Successful", data: user, token });
  } catch (error) {
    console.log(error.message);
    return res.status(500).json({ message: "Error during login" });
  }
};
```
9. We need to add `login` to our `user.Routes.js` file
```javascript
const express = require('express');
const { signUp, login } = require('../controller/userController');
const router = express.Router();

router.post('/signup', signUp);
router.post('/login', login);

module.exports = router;
```
## Now we Test Our Login at `http://localhost:5500/api/v1/user/login`
![Login Test](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/a0l4e3yn2izreh1kuemr.png)

> So we Unhashed the password, logged and Attached Jwt to the User successfully.

![Yay](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/4e1h37v4iv186kpmo46o.gif)

## Lets Do One Last thing Let's Find all Users But we'll make the Route Protected by Jwt
> So we'll add this to the `userController.js` file
```javascript
exports.getAllUsers = async (req, res) => {
  try {
    // Retrieve all users from the database
    const users = await User.find({}, { password: 0 }); // Exclude the password field from the response

    return res.status(200).json({ users });
  } catch (error) {
    console.log(error.message);
    return res.status(500).json({ message: "Error fetching users" });
  }
};
```
> We'll add this to the routes
```javascript
const express = require('express');
const { signUp, login, getAllUsers } = require('../controller/userController');
const router = express.Router();

router.GET('/allusers', getAllUsers);
router.post('/signup', signUp);
router.post('/login', login);

module.exports = router;
```
> When you test on `http://localhost:5500/api/v1/user/allusers` You should get All the users you have in your Database

> Now can protect this route with our Jwt Token, Let's create a file called `isAuth.js` in our `config` folder and it would look like this
```javascript
const jwt = require("jsonwebtoken");

exports.verifyToken = async (req, res, next) => {
  try {
    const token = req.headers.authorization.split(" ")[1];
    if (!token) {
      return res.status(401).json({ error: "Unauthorized" });
    }
    const decoded = await jwt.verify(token, process.env.SECRET_KEY);
    if (!decoded) {
      throw new Error();
    }
    req.user = decoded;

    next();
  } catch (error) {
    console.log(error);
    return res.status(500).json({ message: "Error Validating Token" });
  }
};

```
> Now we need to import `verifyToken` into our Route
> And now our Route looks like this
```javascript
const express = require('express');
const { signUp, login, getAllUsers } = require('../controller/userController');
const { verifyToken } = require('../config/isAuth');
const router = express.Router();

router.get('/allusers', verifyToken, getAllUsers);
router.post('/signup', signUp);
router.post('/login', login);

module.exports = router;
```
## And We Are Done
[Here's a Link To The Github repo for this Project](https://github.com/FredAbod/Authentication-App-Article-)
Please leave a Like And A Comment If This Article Was Helpful And Probably you have any questions. Untill Next Time 

![Bow](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/7mth9ugpdw8735e02fsu.gif)