Platformsh\Cli\Local\LocalProject::getLegacyProjectRoot PHP Method

    public function getLegacyProjectRoot()
    {
        return $this->findTopDirectoryContaining($this->config->get('local.project_config_legacy'));
    }

 /**
  * Prompt the user to migrate from the legacy project file structure.
  *
  * If the input is interactive, the user will be asked to migrate up to once
  * per hour. The time they were last asked will be stored in the project
  * configuration. If the input is not interactive, the user will be warned
  * (on every command run) that they should run the 'legacy-migrate' command.
  */
 protected function promptLegacyMigrate()
 {
     static $asked = false;
     if ($this->localProject->getLegacyProjectRoot() && $this->getName() !== 'legacy-migrate' && !$asked) {
         $asked = true;
         $projectRoot = $this->getProjectRoot();
         $timestamp = time();
         $promptMigrate = true;
         if ($projectRoot) {
             $projectConfig = $this->localProject->getProjectConfig($projectRoot);
             if (isset($projectConfig['migrate']['3.x']['last_asked']) && $projectConfig['migrate']['3.x']['last_asked'] > $timestamp - 3600) {
                 $promptMigrate = false;
             }
         }
         $this->stdErr->writeln('You are in a project using an old file structure, from previous versions of the ' . self::$config->get('application.name') . '.');
         if ($this->input->isInteractive() && $promptMigrate) {
             if ($projectRoot && isset($projectConfig)) {
                 $projectConfig['migrate']['3.x']['last_asked'] = $timestamp;
                 $this->localProject->writeCurrentProjectConfig($projectConfig, $projectRoot);
             }
             /** @var \Platformsh\Cli\Helper\QuestionHelper $questionHelper */
             $questionHelper = $this->getHelper('question');
             if ($questionHelper->confirm('Migrate to the new structure?')) {
                 $code = $this->runOtherCommand('legacy-migrate');
                 exit($code);
             }
         } else {
             $this->stdErr->writeln('Fix this with: <comment>' . self::$config->get('application.executable') . ' legacy-migrate</comment>');
         }
         $this->stdErr->writeln('');
     }
 }