add migration to fix empty checklist.id

migrations/20160527_fix_empty_checklist_id.js

@@ -0,0 +1,78 @@
+var uuid = require('uuid').v4;
+var mongo = require('mongodb').MongoClient;
+var _ = require('lodash');
+
+var taskIds = require('checklists-no-id.json').map(function (obj) {
+  return obj._id;
+});
+
+// Fix empty task.checklistt.id
+
+var progressCount = 100;
+var count = 0;
+
+function displayData() {
+  console.warn('\n' + count + ' tasks processed\n');
+  return exiting(0);
+}
+
+function exiting(code, msg) {
+  code = code || 0; // 0 = success
+
+  if (code && !msg) { msg = 'ERROR!'; }
+  if (msg) {
+    if (code) { console.error(msg); }
+    else      { console.log(  msg); }
+  }
+}
+
+mongo.connect('db url')
+.then(function (db) {
+  var dbTasks = db.collection('tasks');
+
+  // specify a query to limit the affected tasks (empty for all tasks):
+  var query = {
+    '_id':{ $in: taskIds },
+  };
+
+  // specify fields we are interested in to limit retrieved data (empty if we're not reading data):
+  var fields = {
+    'checklist': 1,
+  };
+
+  console.warn('Updating tasks...');
+
+  dbTasks.find(query, fields, {batchSize: 250}).toArray(function(err, tasks) {
+    if (err) { return exiting(1, 'ERROR! ' + err); }
+
+    tasks.forEach(function (task) {
+      var checklist = task.checklist || [];
+      checklist.forEach(function (item) {
+        if (!item.id || item.id === "") {
+          item.id = uuid();
+        }
+      });
+
+      // specify user data to change:
+      var set = {
+        checklist: checklist,
+      };
+      //console.log(set);
+
+      dbTasks.update({_id: task._id}, {$set: set}, function (err, res) {
+        if (err) console.error('Error while updating', err);
+      });
+
+      count++;
+      if (count % progressCount == 0) console.warn(count + ' ' + task._id);
+    });
+
+    if (count === tasks.length) {
+      console.warn('All appropriate tasks found and modified.');
+      return displayData();
+    }
+  });
+})
+.catch(function (err) {
+  throw err;
+});