How can I handle errors in Express.js?

How can I handle errors in Express.js?

In Express.js, you can handle errors by using middleware. You can create an error-handling middleware function that takes four arguments: err, req, res, and next. This function can be used to catch errors and send appropriate responses.

Can you show 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).send('Something broke!');
});

What if I want to handle different types of errors?

You can check the error type within your middleware and respond accordingly. For example, you can differentiate between validation errors and server errors.

Is there a way to log errors to a file?

Yes, you can use libraries like winston or morgan to log errors to a file. You would set up a logger and call it within your error-handling middleware.