--TEST-- Single Application can be executed --ARGS-- You --FILE-- <?php use Symfony\Component\Console\Input\InputArgument; use Symfony\Component\Console\Input\InputInterface; use Symfony\Component\Console\Output\OutputInterface; use Symfony\Component\Console\SingleCommandApplication; $vendor = __DIR__; while (!file_exists($vendor.'/vendor')) { $vendor = dirname($vendor); } require $vendor.'/vendor/autoload.php'; (new SingleCommandApplication()) ->addArgument('who', InputArgument::OPTIONAL, 'Who', 'World') ->setCode(function (InputInterface $input, OutputInterface $output): int { $output->writeln(sprintf('Hello %s!', $input->getArgument('who'))); return 0; }) ->run() ; ?> --EXPECT-- Hello You!