How can I handle authentication errors in a MERN application?

How can I handle authentication errors in a MERN application?

You can handle authentication errors in a MERN app by implementing error handling middleware in your Express server.

What kind of errors should I be looking for?

Look for errors like invalid credentials, expired tokens, and unauthorized access attempts.

How do I send error messages back to the client?

You can send error messages by using res.status() to set the HTTP status code and res.json() to send the error message.

Can you give me an example of error handling middleware?

Sure! Here's a simple example:

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).json({ message: 'Something went wrong!' });
});