habitica/migrations/20131104_restore_lost_task_data.js

// node .migrations/20131104_restore_lost_task_data.js

/**
 * After the great challenges migration, quite a few things got inadvertently dropped from tasks since their
 * schemas became more strict. See conversation at https://github.com/HabitRPG/habitrpg/issues/1712 ,
 * this restores task tags, streaks, due-dates, values
 */
var mongo = require('mongoskin');
var _ = require('lodash');

var backupUsers = mongo.db('localhost:27017/habitrpg_old?auto_reconnect').collection('users');
var liveUsers = mongo.db('localhost:27017/habitrpg_new?auto_reconnect').collection('users');

backupUsers.count(function(err, count){
  if (err) return console.error(err);
  backupUsers.findEach({}, {batchSize:250}, function(err, before){
    if (err) return console.error(err);
    if (!before) return console.log('!before');
    liveUsers.findById(before._id, function(err, after){
      if (err) return console.error(err);
      if (!after) {
        count--;
        return console.log(before._id + ' deleted?');
      }
      if (before._id == '9') console.log('lefnire processed');
      _.each(before.tasks, function(tBefore){
        var tAfter = _.find(after[tBefore.type+'s'], {id:tBefore.id});
        if (!tAfter) return; // task has been deleted since launch

        // Restore deleted tags
        if (!_.isEmpty(tBefore.tags) && _.isEmpty(tAfter.tags))
          tAfter.tags = tBefore.tags;
        // Except tags which are no longer available on the updated user
        _.each(tAfter.tags, function(v,k){ //value is true, key is tag.id
          if (!_.find(after.tags,{id:k})) delete tAfter.tags[k];
        })

        // Restore deleted streaks
        if (+tBefore.streak > tAfter.streak)
          tAfter.streak = +tBefore.streak;

        if (!!tBefore.date && !tAfter.date)
          tAfter.date = tBefore.date;

        // Restore deleted values
        if (+tBefore.value != 0 && tAfter.value == 0)
          tAfter.value = +tBefore.value;
      })
      after._v++;
      liveUsers.update({_id:after._id}, after);
      if (--count <= 0) console.log("DONE!");
    })
  });
});