magento2/app/code/Magento/Backend/Service/V1/ModuleService.php

<?php
/**
 * Magento
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * 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 license@magentocommerce.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magentocommerce.com for more information.
 *
 * @copyright   Copyright (c) 2014 X.commerce, Inc. (http://www.magentocommerce.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

namespace Magento\Backend\Service\V1;

/**
 * Module service.
 */
class ModuleService implements ModuleServiceInterface
{
    /**
     * @var \Magento\Framework\Module\ModuleListInterface
     */
    protected $moduleList;
    /**
     * @param \Magento\Framework\Module\ModuleListInterface $moduleList
     */
    public function __construct(
        \Magento\Framework\Module\ModuleListInterface $moduleList
    ) {
        $this->moduleList = $moduleList;
    }

    /**
     * Returns an array of enabled modules
     *
     * @return string[]
     */
    public function getModules()
    {
        $result = [];
        $modules = $this->moduleList->getModules();
        foreach ($modules as $module) {
            $result[] = $module['name'];
        }
        return $result;
    }
}