How can I handle errors in Passport.js?

How can I handle errors in Passport.js?

In Passport.js, you can handle errors by using middleware to catch authentication errors. You can define a custom callback for the authentication strategy that checks for errors and handles them accordingly.

Can you show me an example of that?

Sure! Here's a simple example:

passport.authenticate('local', function(err, user, info) {
  if (err) {
    return res.status(500).json({ message: 'Authentication error', error: err });
  }
  if (!user) {
    return res.status(401).json({ message: 'Invalid credentials' });
  }
  // Proceed with login
})(req, res);

What if I want to log these errors for debugging?

You can use a logging library like Winston or Morgan to log errors. Just add a logging statement in the error handling section of your middleware.

Is there a way to customize the error messages returned to the user?

Yes, you can customize the error messages by modifying the response in the error handling section. Just replace the default messages with your custom ones.