Mass-edit emails of users on DemocracyOS on mongoose

script.js

var OWNER_EMAIL = process.env.OWNER_EMAIL || 'debug-email@gmail.com'

//--------------------------

require('lib/models')()

var config = require('lib/config')
var models = require('lib/models')

var User = models.User

Promise.all([
  User.findOne({email: OWNER_EMAIL}).exec(),
  User.find({email: {$ne: OWNER_EMAIL}}).count().exec()
]).then(function (results) {
  var owner = results[0]
  var count = results[1]

  if (!owner) throw new Error('need to set a real owner reference User')

  console.log(`· processing ${count} users`)

  var done = 0
  User.find({
    email: {$ne: OWNER_EMAIL}
  }).stream().on('data', function (user) {
    user.email = owner.email.replace('@', `+${user._id}@`)
    user.salt = owner.salt
    user.hash = owner.hash

    user.save(function (err) {
      if (err) console.error(err, user.email)
      if (++done === count) {
        console.log('· done!')
        process.exit(0)
      }
    })
  }).on('error', console.error.bind(console))
}).catch(function (err) {
  console.error(err)
  process.exit(1)
})