asyncProcess.js

async function track (msg) {
  return Promise.resolve(foo) // intentially triggering ReferenceError for undefined `foo`
}

async function process (msg, done) {
  
  try {
    const res = await track(msg)
    return done(null, res)
  } catch (e) {
    // If an err code hasn't been applied, we can assume this was uncaught by the integration's own err handler.
    err.code = err.code || 'INTERNAL'
    err.retry = true
    return done(err)
  }
}

function onMessage (msg) {
  process(msg, (err, res) => {
     // log err/res to datadog or whatever...
    if (err) {
      stats.err(err)
    } else {
      stats.success(res)
    }
  })
}