Remove Duplicates From GDrive Root

code.js

/*
  Gunar C. Gessner
  @gunar 2016
  
  INSTALL: https://script.google.com/macros/s/AKfycbym7IaTORzJ7LQPcxMx1LV1SQEC6RVGv5tzLOgYS8iQe8XAJxM/exec
  
  After installation, the script will, every 10 minutes, search for all files that have duplicates (shift+z) and remove them from the root directory ("My Drive").

  This Google Apps Script webapp aims to solve the problem that when transferring ownership of folders &
  files to another account, duplicate files shown in "My Drive".
  
  Original Google Drive Help forum issue: https://productforums.google.com/forum/#!topic/drive/Ldz7nvSXQ6w
  
*/

'use strict'

function updateTriggers(triggerId) {
  // Remove all project Triggers
  var allTriggers = ScriptApp.getProjectTriggers();
  for (var i = 0; i < allTriggers.length; i++) {
    ScriptApp.deleteTrigger(allTriggers[i]);
  }
  // Add single one
  ScriptApp.newTrigger('removeDuplicatesFromRoot')
    .timeBased()
    .everyMinutes(10)
    .create();
}

function doGet() {
  updateTriggers();
  return HtmlService.createHtmlOutput('Script successfully installed! It will remove duplicates every 10 minutes.');
}

function removeDuplicatesFromRoot() {
  Logger.clear();
  var rootFolder = DriveApp.getRootFolder();
  var files = rootFolder.getFiles();
  while (files.hasNext()) {
   var file = files.next();
   var parents = file.getParents();
   var isInMyDrive = false;
   var isSomewhereElse = false;
   while (parents.hasNext()) {
     var folder = parents.next();
     if (folder == 'My Drive') { isInMyDrive = true }
     else { isSomewhereElse = true }
   }
   Logger.log('===' + file + ': ' + isInMyDrive + '/' + isSomewhereElse);
   if (isInMyDrive && isSomewhereElse) { rootFolder.removeFile(file); }
  }
}