Reserve promise rejections (i.e. async exceptions) for exceptional circumstances

With the browser’s native prompt function, pressing cancel doesn’t result in an error, but instead a null return value. (Similarly, with the native alert function, hitting escape doesn’t result in an error, and with the native confirm function, clicking no doesn’t result in an error but instead a false return value.)

I believe this to be the desired behavior. Especially when using the up-coming async/await feature of ES (being used already via Babel), the current swal2 behavior leads to some awkward control-flow…

let result
let error
try {
  result = await swal({
    text: 'What is your favorite color?'
    input: text,
    showCancelButton: true
  })
} catch (_error) {
  error = _error
}
if (error) {
  swal('I did not get your favorite color because "${error}".')
} else {
  swal(`Your favorite color is ${result}.`)
}

The following would be a bit nicer.

const result = await swal({
  text: 'What is your favorite color?'
  input: text,
  showCancelButton: true
})
if (result.dismiss) {
  swal('I did not get your favorite color because "${result.dismiss}".')
} else {
  swal(`Your favorite color is ${result.value}.`)
}

@limonte Would you review a PR adding an option to enable this behavior? Let’s call the option rejections and have it default to true?

[zenflow]

const {dismiss, value: favoriteColor} = await swal({text: 'What is your favorite color?', input: 'text'})
if (dismiss) {
  swal(`I did not get your favorite color because "${dismiss}".`)
} else {
  swal(`Your favorite color is "${favoriteColor}".`)
}

const {value: name} = await swal({text: 'Full name?', input: 'text'})
const {value: location} = await swal({text: 'Location?', input 'text'})
await swal(`Hi ${name}, from ${location}!`)

[toverux]

rude answer to rude message: https://gist.github.com/Rich-Harris/0b6f317657f5167663b493c722647221