How to delete cookie on logout in express + passport js?

When implementing user logout in the Express framework combined with Passport.js for user authentication, it typically involves invalidating the session and deleting authentication-related cookies. Specifically, to delete cookies during logout, we can follow these steps:

1. Set Cookie: First, ensure that cookies are set during login. This is typically done in the Passport login callback, for example, using the res.cookie() method.

2. Create Logout Route: In Express, you need a dedicated route to handle user logout.

3. Clear Cookies: In this logout route, in addition to calling req.logout() to clear the session, you also need to clear the cookies.

The following is a simple code example demonstrating this process:

javascript
const express = require('express');
const passport = require('passport');

const app = express();

// Assume Passport initialization and session configuration are already set

// Login route
app.post('/login', passport.authenticate('local', {
  successRedirect: '/',
  failureRedirect: '/login'
}), (req, res) => {
  // Set cookie, e.g., sessionID
  res.cookie('session_id', '123456');
});

// Logout route
app.get('/logout', (req, res) => {
  // Logout user
  req.logout();

  // Clear all related cookies
  res.clearCookie('session_id');

  // Redirect to login page or homepage
  res.redirect('/login');
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

In this example, after login, a cookie named session_id is set. Then, in the logout route, we first call req.logout() to clear the session (a Passport.js method), followed by using res.clearCookie('session_id') to delete the specified cookie. Finally, the user is redirected to the login page.

This approach ensures that when users log out, their session information and authentication-related cookies are cleared, thereby enhancing the application's security.