Setting Up an Express.js Server with User Authentication Middleware

Unfortunately, the Code Generator AI cannot produce an Express.js server setup with user authentication middleware directly. However, I can guide you through the process of setting up an Express.js server with user authentication middleware using the Passport.js library.

Passport.js is a popular authentication library that provides a wide range of authentication strategies like local, social (e.g., Google, Facebook, etc.), and more. It is also highly extensible, allowing you to integrate custom authentication strategies if needed.

To set up an Express.js server with user authentication middleware, follow these steps:

1. Install the necessary dependencies:

npm install express passport passport-local express-session

2. Set up the Express.js server, configure middleware, and database connection:

const express = require('express');
const passport = require('passport');
const LocalStrategy = require('passport-local').Strategy;
const session = require('express-session');

const app = express();

// Configure session middleware
app.use(session({
  secret: 'your-secret-key',
  resave: false,
  saveUninitialized: false
}));

// Configure passport.initialize() middleware
app.use(passport.initialize());

// Configure passport.session() middleware
app.use(passport.session());

// Set up database connection

// Define models

// Define routes

// Start the server
app.listen(3000, () => {
  console.log('Server started on port 3000');
});

3. Configure Passport.js strategies:

passport.use(new LocalStrategy(
  (username, password, done) => {
    // Use your database model to find the user by username and validate the password
    User.findOne({ username: username }, (err, user) => {
      if (err) return done(err);
      if (!user) return done(null, false, { message: 'Incorrect username.' });
      if (!user.validPassword(password)) return done(null, false, { message: 'Incorrect password.' });
      return done(null, user);
    });
  }
));

4. Configure Passport.js serialization and deserialization:

passport.serializeUser((user, done) => {
  done(null, user.id);
});

passport.deserializeUser((id, done) => {
  User.findById(id, (err, user) => {
    done(err, user);
  });
});

5. Define routes for authentication:

app.post('/login', passport.authenticate('local', {
  successRedirect: '/',
  failureRedirect: '/login'
}));

app.get('/logout', (req, res) => {
  req.logout();
  res.redirect('/login');
});

6. Protect your routes by adding the authentication middleware:

function requireAuth(req, res, next) {
  if (req.isAuthenticated()) {
    return next();
  }
  res.redirect('/login');
}

app.get('/', requireAuth, (req, res) => {
  res.send('Authenticated route');
});

Now, you have an Express.js server with user authentication middleware using Passport.js. You can further customize the authentication setup and add additional strategies as needed.

Example usage:

// Set up Express.js server with user authentication middleware
// ...

// Set up your routes and models
// ...

// Start the server
app.listen(3000, () => {
  console.log('Server started on port 3000');
});

Unit testing:

To unit test this setup, you can use libraries like Mocha and Chai to test each component of the server and authentication middleware. Perform tests to ensure that user registration, authentication, and protected routes work as expected.