What are the best practices for error handling in Koa?

What are the best practices for error handling in Koa?

The best practices for error handling in Koa include using middleware for centralized error handling, logging errors, and sending appropriate HTTP status codes.

Can you explain how to implement centralized error handling?

Sure! You can create a custom error handling middleware that catches errors and formats the response. Here's a simple example:

app.use(async (ctx, next) => {
  try {
    await next();
  } catch (err) {
    ctx.status = err.status || 500;
    ctx.body = { message: err.message };
    console.error(err);
  }
});

What should I log when an error occurs?

You should log the error message, stack trace, and any relevant request information like the URL, method, and parameters to help with debugging.

How can I send different status codes based on the error type?

You can check the error type in your catch block and set the status code accordingly. For example:

if (err instanceof NotFoundError) {
  ctx.status = 404;
} else if (err instanceof ValidationError) {
  ctx.status = 400;
} else {
  ctx.status = 500;
}