Error Handling in LINE

Customizing the Error Message in LINE

Your bot can only reply to the user once after a user interacts with your LINE official account. However, the error may happen when calling Reply API. So, you can check the value of context.isReplied before replying to the user in your error handler:

// _error.js

module.exports = async function HandleError(context, props) {
  console.error(props.error);
  if (!context.isReplied) {
    // or you can choose not to reply any error messages
    await context.replyText(
      'There are some unexpected errors happened. Please try again later, sorry for the inconvenience.'
    );
  }
  if (process.env.NODE_ENV === 'production') {
    // send your error to the error tracker, for example: Sentry
  }
};

For more information, you may refer to Customizing the Error Message for the basic knowledge of error handling.