Promises instead of callbacks

[MoritzCooks]

I implemented react-native-health and react-native-health-connect. I try to get these packages together in one lib file. What bothers me the most, is that react-native-health is taking callbacks instead of simply returning promises.
Is there any reason not to return a promise?

With the current approach you either need an additional state variable that reflects the isAvailable state or you wrap the function in a promise. My current implementation of checking if the HealthKit is available looks somewhat like this:

const isAvailable = await new Promise(resolve => {
  AppleHealthKit.isAvailable((err, available) => {
    if (err) Sentry.captureException(err)

    return resolve(available)
  })
}

I have to wrap a promise around it, to be able to await the resolved value. I could get rid of this promise wrapper if the isAvailable method would simply return a promise instead. Also it would look a lot cleaner not only because of less nesting:

try {
  return await AppleHealthKit.isAvailable()
} catch (error) {
  Sentry.captureException(error)
}
return false

I saw this in a couple methods of this package that the result gets returned with a callback. This pattern is quite uncommon in my opinion. And as I already pointed out it needs additional wrappers to actually await the response.