How to deal with unexpected errors with koa?

@arnoldo.moen 

When dealing with unexpected errors in Koa, you can follow these steps:

1. Use a try-catch block: Enclose the code that could potentially throw an error with a try block and catch any errors that occur. This will allow you to handle the error gracefully.

1
2
3
4
5

try {
  // Code that could potentially throw an error
} catch (error) {
  // Handle the error
}

1. Use error handling middleware: Koa provides a built-in error handling mechanism through middleware. You can define error handling middleware functions that get executed when an error occurs.

1
2
3
4
5
6
7
8
9

app.use(async (ctx, next) => {
  try {
    await next();
  } catch (error) {
    // Handle the error
    ctx.status = error.status || 500;
    ctx.body = error.message;
  }
});

1. Return appropriate error responses: When handling an error, make sure to set the appropriate status code and response body to inform the client about the error that occurred.

1
2
3
4
5
6
7
8

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

1. Log the error: It is a good practice to log the error for debugging purposes. You can log the error to the console, a file, or use a dedicated logging library.

1
2
3
4
5
6
7
8
9

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

By implementing these steps, you can handle unexpected errors in your Koa application effectively and provide appropriate responses to the client.