Symfony2 command unit test helper class.

AbstractCommandTestHelper.php

<?php

namespace Ladbible\BaseBundle\Tests\Command;

use Symfony\Bundle\FrameworkBundle\Client;
use Symfony\Component\Console\Input\StringInput;
use Symfony\Component\Console\Output\StreamOutput;
use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
use Symfony\Bundle\FrameworkBundle\Console\Application;

/**
 * AbstractCommandTestHelper
 *
 * @author    Ewan Valentine <ewan@theladbible.com>
 * @copyright 65Twenty 2015
 */
abstract class AbstractCommandTestHelper extends WebTestCase
{
	/**
	 * runCommand
	 *
	 * Creates instance of Application in 
	 * test mode and allows commands to be
	 * ran. 
	 * 
	 * @param  Client $client  
	 * @param  string $command 
	 * 
	 * @return mixed
	 */
	public function runCommand(Client $client, $command)
	{
		// Create separate instance of application kernel
	    	$application = new Application($client->getKernel());

	    	// Set auto exit application to false
	    	$application->setAutoExit(false);

	    	// Create a temporary file to contain command output
            	$fp = tmpfile();

            	// Command input
            	$input = new StringInput($command);

            	// Stream output to temporary file
            	$output = new StreamOutput($fp);

            	// Run command
            	$application->run($input, $output);

            	// Finds first byte in temporary file
            	fseek($fp, 0);
        	
            	// Resets output
            	$output = '';	

            	// Iterates through 'til end of temporary file
            	while (!feof($fp)) {
        	    $output = fread($fp, 4096);
        	}
        
            	// Closes file stream
            	fclose($fp);

            	// Returns final output
            	return $output;
	}
}