phake\Builder::resolve_runfile PHP Method

    public function resolve_runfile($directory)
    {
        $directory = rtrim($directory, '/') . '/';
        $runfiles = array('Phakefile', 'Phakefile.php');
        do {
            foreach ($runfiles as $r) {
                $candidate = $directory . $r;
                if (file_exists($candidate)) {
                    return $candidate;
                }
            }
            if ($directory == '/') {
                throw new \Exception("No Phakefile found");
            }
            $directory = dirname($directory);
        } while (true);
    }

 public function execute($args)
 {
     try {
         //
         // Defaults
         $action = 'invoke';
         $task_names = array('default');
         $trace = false;
         $runfile = false;
         $run_safely = true;
         array_shift($args);
         $parser = new OptionParser($args);
         foreach ($parser->get_options() as $option => $value) {
             switch ($option) {
                 case 't':
                 case 'trace':
                     $trace = true;
                     break;
                 case 'T':
                 case 'tasks':
                     $action = 'list';
                     break;
                 case 'f':
                 case 'file':
                     $runfile = $value;
                     break;
                 case 'u':
                 case 'unsafe':
                     $run_safely = false;
                     break;
                 default:
                     throw new Exception("Unknown command line option '{$option}'");
             }
         }
         $cli_args = array();
         $cli_task_names = array();
         foreach ($parser->get_non_options() as $option) {
             if (strpos($option, '=') > 0) {
                 $cli_args[] = $option;
             } else {
                 $cli_task_names[] = $option;
             }
         }
         $cli_args = Utils::parse_args($cli_args);
         if (count($cli_task_names)) {
             $task_names = $cli_task_names;
         }
         $application = new Application();
         $builder = new Builder($application);
         //
         // Locate runfile
         if (!$runfile) {
             $runfile = $builder->resolve_runfile(getcwd());
             $directory = dirname($runfile);
             if (!@chdir($directory)) {
                 throw new Exception("Couldn't change to directory '{$directory}'");
             } else {
                 echo "(in {$directory})\n";
             }
         }
         $builder->load_runfile($runfile);
         //
         // Go, go, go
         $application->set_args($cli_args);
         $application->reset();
         if ($run_safely) {
             $does_cycle = $this->detect_and_display_cycles($application);
             if ($does_cycle) {
                 throw new TaskCycleFoundException();
             }
         }
         switch ($action) {
             case 'list':
                 $task_list = $application->get_task_list();
                 if (count($task_list)) {
                     $max = max(array_map('strlen', array_keys($task_list)));
                     foreach ($task_list as $name => $desc) {
                         echo str_pad($name, $max + 4) . $desc . "\n";
                     }
                 }
                 break;
             case 'invoke':
                 foreach ($task_names as $task_name) {
                     $application->invoke($task_name);
                 }
                 break;
         }
     } catch (TaskNotFoundException $tnfe) {
         $this->fatal($tnfe, sprintf("Don't know how to build task '%s'\n", $tnfe->getTaskName()), $trace);
     } catch (Exception $e) {
         $this->fatal($e, null, $trace);
     }
 }