Symfony2功能测试客户端请求返回错误500

我有一个控制器，我想为它做一个功能测试。

控制器:

<?php
namespace Zanox'AppBundle'Controller;
use Symfony'Bundle'FrameworkBundle'Controller'Controller;
use Symfony'Component'Routing'Annotation'Route;
use Exception;
/**
 * 
 * @author Mohamed Ragab Dahab <eng.mohamed.dahab@gmail.com>
 * 
 * @Route("merchant")
 * 
 */
class ReportController extends Controller {
    /**
     * Show transaction report regarding to the given merchant ID
     * @author Mohamed Ragab Dahab <eng.mohamed.dahab@gmail.com>
     * @access public
     * 
     * @Route("/{id}/report", name="merchant-report")
     * 
     * @param int $id   Merchant ID
     */
    public function showAction($id) {
        try {
            //Order Service
            $orderService = $this->get('zanox_app.orderService');
            //merchant Orders
            $orders = $orderService->getMerchantOrders($id);
            //render view and pass orders array
            return $this->render('ZanoxAppBundle:Report:show.html.twig', ['orders' => $orders]);
        } catch (Exception $e) {
            //log errors
        }
    }
}

namespace Zanox'AppBundle'Tests'Controller;
use Symfony'Bundle'FrameworkBundle'Test'WebTestCase;
class ReportControllerTest extends WebTestCase {
    /**
     * 
     */
    public function testShow() {
        //Client instance
        $client = static::createClient();
        //Act like browsing the merchant listing page, via GET method
        $crawler = $client->request('GET', '/merchant/{id}/report', ['id'=> 1]);
        //Getting the response of the requested URL
        $crawlerResponse = $client->getResponse();
        //Assert that Page is loaded ok
        $this->assertEquals(200, $crawlerResponse->getStatusCode());
        //Assert that the response content contains 'Merchant Listing' text
        $this->assertTrue($crawler->filter('html:contains("Merchant Report")')->count() > 0);
    }
}

但是这个测试失败，因为第一个断言返回的状态是500而不是200

测试日志显示:[2015-07-06 21:00:24]请求。信息:匹配路线"merchant-report"。{" route_parameters ":{"_controller":"Zanox ' AppBundle '控制器' ReportController:: showAction"、"id":"{id}","_route":"merchant-report"},"request_uri":"http://localhost/merchant/{id}/报告吗?id = 1 "} []

让您知道['id' => 1]在数据库中存在。

第一个问题:为什么失败?

第二个问题:我做功能测试的方式是否正确?