laravel5/vendor/symfony/error-handler/Debug.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\ErrorHandler;

/**
 * Registers all the debug tools.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class Debug
{
    public static function enable(): ErrorHandler
    {
        error_reporting(-1);

        if (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {
            ini_set('display_errors', 0);
        } elseif (!filter_var(ini_get('log_errors'), \FILTER_VALIDATE_BOOLEAN) || ini_get('error_log')) {
            // CLI - display errors only if they're not already logged to STDERR
            ini_set('display_errors', 1);
        }

        @ini_set('zend.assertions', 1);
        ini_set('assert.active', 1);
        ini_set('assert.warning', 0);
        ini_set('assert.exception', 1);

        DebugClassLoader::enable();

        return ErrorHandler::register(new ErrorHandler(new BufferingLogger(), true));
    }
}