habitica/migrations/20151021_usernames_emails_lowercase.js

/*
 * Migrate email to lowerCase version and add auth.local.lowerCaseUsername email
 */

var mongo = require('mongoskin');
var async = require('async');

var dbserver = 'url';
var dbname = 'dbname';
var countUsers = 0;

var db = mongo.db(dbserver + '/' + dbname + '?auto_reconnect');
var dbUsers = db.collection('users');

console.log('Begins work on db');

function findUsers(gt){
  var query = {};
  if(gt) query._id = {$gt: gt};

  console.log(query)

  dbUsers.find(query, {
    fields: {_id: 1, auth: 1},
    limit: 10000,
    sort: {
      _id: 1
    }
  }).toArray(function(err, users){
    if(err) throw err;

    var lastUser = null;
    if(users.length === 10000){
      lastUser = users[users.length - 1];
    }

    async.eachLimit(users, 20, function(user, cb){
      countUsers++;
      console.log('User: ', countUsers, user._id);

      var update = {
        $set: {}
      };

      if(user.auth && user.auth.local) {
        if(user.auth.local.username) update['$set']['auth.local.lowerCaseUsername'] = user.auth.local.username.toLowerCase();
        if(user.auth.local.email) update['$set']['auth.local.email'] = user.auth.local.email.toLowerCase();
      }

      dbUsers.update({
        _id: user._id
      }, update, cb);
    }, function(err){
      if(err) throw err;

      if(lastUser && lastUser._id){
        findUsers(lastUser._id);
      }
    });
  });
};

findUsers();