Gist do post "Usando PHPUnit no Codeigniter via Hooks" Link: http://willmendesnetoprojects.wordpress.com/2013/02/24/usando-phpunit-no-codeigniter-via-hooks/

hooks.php

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.2.4 or newer
 *
 * NOTICE OF LICENSE
 *
 * Licensed under the Academic Free License version 3.0
 *
 * This source file is subject to the Academic Free License (AFL 3.0) that is
 * bundled with this package in the files license_afl.txt / license_afl.rst.
 * It is also available through the world wide web at this URL:
 * http://opensource.org/licenses/AFL-3.0
 * If you did not receive a copy of the license and are unable to obtain it
 * through the world wide web, please send an email to
 * licensing@ellislab.com so we can send you a copy immediately.
 *
 * @package    	CodeIgniter
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2013, EllisLab, Inc. (http://ellislab.com/)
 * @license		http://opensource.org/licenses/AFL-3.0 Academic Free License (AFL 3.0)
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

/*
| -------------------------------------------------------------------------
| Hooks
| -------------------------------------------------------------------------
| This file lets you define "hooks" to extend CI without hacking the core
| files.  Please see the user guide for info:
|
|	http://codeigniter.com/user_guide/general/hooks.html
|
*/

$hook['display_override'] = array(
    'class' => 'DisplayHook',
    'function' => 'captureOutput',
    'filename' => 'DisplayHook.php',
    'filepath' => 'hooks'
);

/* End of file hooks.php */
/* Location: ./application/config/hooks.php */

Olá,

usei este e mais alguns dos seus gists para compor um artigo sobre Codeigniter e PHPUnit que escrevi baseado no seu. http://taiar.github.io/php/2013/11/08/testando-aplicacoes-codeigniter-com-phpunit.html

Obrigado pelas referências!

Abraços.