How can I implement error handling in Express middleware?

How can I implement error handling in Express middleware?

You can create a custom error-handling middleware function in Express. It should have four parameters: err, req, res, and next. Here's a basic 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 differently?

You can check the error type within your middleware and respond accordingly. For example:

app.use((err, req, res, next) => {
    if (err instanceof ValidationError) {
        return res.status(400).send(err.message);
    }
    res.status(500).send('Internal Server Error');
});

Can I log errors to an external service?

Yes, you can integrate logging libraries like Winston or use services like Sentry to log errors. Just call the logging function in your error handler.

Is it possible to send error details in the response?

Absolutely! You can include error details in the response, but be cautious not to expose sensitive information. For example:

app.use((err, req, res, next) => {
    res.status(err.status || 500).json({ error: err.message });
});