How do I create authentication middleware in Express?

How do I create authentication middleware in Express?

To create authentication middleware in Express, you can start by defining a function that checks if a user is authenticated.

What should the middleware function check for?

The middleware should check for a valid token or session, typically by looking for a JWT in the request headers.

Can you show me a code example?

Sure! Here's a simple example:

function authenticate(req, res, next) {
    const token = req.headers['authorization'];
    if (!token) return res.status(401).send('Access Denied');
    // Verify token logic here
    next();
}

How do I use this middleware in my routes?

You can use it like this:

app.get('/protected', authenticate, (req, res) => {
    res.send('This is a protected route');
});