Go\Instrument\FileSystem\Enumerator::enumerate PHP Method

    public function enumerate()
    {
        $iterator = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->rootDirectory, \FilesystemIterator::SKIP_DOTS));
        $callback = $this->getFilter();
        $iterator = new \CallbackFilterIterator($iterator, $callback);
        return $iterator;
    }

 /**
  * {@inheritdoc}
  */
 protected function execute(InputInterface $input, OutputInterface $output)
 {
     $output->writeln('Start up application with supplied config...');
     $config = $input->getArgument('applicationConfig');
     $path = stream_resolve_include_path($config);
     if (!is_readable($path)) {
         throw new \InvalidArgumentException("Invalid loader path: {$config}");
     }
     // Init the application once using given config
     // This way the late static binding on the AspectKernel
     // will be on the goaop-zf2-module kernel
     \Zend\Mvc\Application::init(include $path);
     if (!class_exists(AspectKernel::class, false)) {
         $message = "Kernel was not initialized yet. Maybe missing module Go\\ZF2\\GoAopModule in config {$path}";
         throw new \InvalidArgumentException($message);
     }
     $kernel = AspectKernel::getInstance();
     $options = $kernel->getOptions();
     if (empty($options['cacheDir'])) {
         throw new \InvalidArgumentException('Cache warmer require the `cacheDir` options to be configured');
     }
     $enumerator = new Enumerator($options['appDir'], $options['includePaths'], $options['excludePaths']);
     $iterator = $enumerator->enumerate();
     $totalFiles = iterator_count($iterator);
     $output->writeln("Total <info>{$totalFiles}</info> files to process.");
     $iterator->rewind();
     set_error_handler(function ($errno, $errstr, $errfile, $errline) {
         throw new \ErrorException($errstr, $errno, 0, $errfile, $errline);
     });
     $index = 0;
     $errors = [];
     foreach ($iterator as $file) {
         if ($output->getVerbosity() >= OutputInterface::VERBOSITY_VERBOSE) {
             $output->writeln("Processing file <info>{$file->getRealPath()}</info>");
         }
         $isSuccess = null;
         try {
             // This will trigger creation of cache
             file_get_contents(FilterInjectorTransformer::PHP_FILTER_READ . SourceTransformingLoader::FILTER_IDENTIFIER . '/resource=' . $file->getRealPath());
             $isSuccess = true;
         } catch (\Exception $e) {
             $isSuccess = false;
             $errors[$file->getRealPath()] = $e;
         }
         if ($output->getVerbosity() == OutputInterface::VERBOSITY_NORMAL) {
             $output->write($isSuccess ? '.' : '<error>E</error>');
             if (++$index % 50 == 0) {
                 $output->writeln("({$index}/{$totalFiles})");
             }
         }
     }
     restore_error_handler();
     if ($output->getVerbosity() >= OutputInterface::VERBOSITY_VERY_VERBOSE) {
         foreach ($errors as $file => $error) {
             $message = "File {$file} is not processed correctly due to exception: {$error->getMessage()}";
             $output->writeln($message);
         }
     }
     $output->writeln('<info>Done</info>');
 }