Error Handling

Sometimes, your bot will fail performing an action, maybe due to bugs or a bad network request. In order to catch these and present them to the end user, you will need to create an error handler.

Any errors that could be produced can either be thrown within a command handler, or passed into the next function.

router
  .command('error', ({ content }) => {
    // Errors produced by the error function is thrown, and caught by HaSeul.
    throw new Error('Cannot process Go Won\'s crunchy voice');
  })
  .command('mei', ({ content, next }) => {
    // Errors produced by the fetch function is passed into the `next` function.
    fetch('http://example.com/')
      .then(data => data.text())
      .then(data => console.log(data))
      .catch(error => next(error))
  })
  .error(({ err }) => {
    console.log('An error was caught!');
    console.log(err);
  })

This error handler will catch errors thrown by handlers created before the error handler.