Symfony 单元测试自定义事件监听器

Question

我有自己的事件监听器：

namespace AppBundle\EventHandlers;

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpFoundation\Response;

class MyExceptionListener
{
    /**
    * @var string
    */
    private $env;

    /**
     * @var null|\Twig_Environment
     */
    private $twig=null;

    private $forOfourExceptions=[
      AppBunble\Exceptions\ApiReturnedNoDataException::class,
      AppBunble\Exceptions\DatabaseReturnedNoDataException::class,
      Symfony\Component\HttpKernel\Exception\NotFoundHttpException::class
    ];

    public function __construct($env,\Twig_Environment $twig)
    {
      $this->env = $env;
      $this->twig=$twig;
    }

    public function onKernelException(GetResponseForExceptionEvent $event)
    {
        // You get the exception object from the received event
        $exception = $event->getException();

        $exceptionClass=get_class($exception);

        // Customize your response object to display the exception details
        $response = new Response();

        $content="";
        if(in_array($exceptionClass,ExceptionMapping::RETURN_ERROR_FOUR_HUNDRED_FOUR)){
            $response ->setStatusCode(Response::HTTP_NOT_FOUND);
            $content = $this->twig->render('error_404.html.twig');
        } else {
            $response ->setStatusCode(Response::HTTP_INTERNAL_SERVER_ERROR);

            if($this->env == 'dev'){//Only on production set response
                return;
            }
        }

        $response->setContent($content);

        // Send the modified response object to the event
        $event->setResponse($response);
    }
}

我做了以下单元测试：

namespace AppBundle\Tests\EventHandlers;

use AppBundle\Exceptions\ApiReturnedNoDataException;
use PHPUnit\Framework\TestCase;
use AppBundle\EventHandlers\MyExceptionListener;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;

class ExceptionListenerTest extends TestCase
{

    public function testnoDataExceptionTest()
    {
        /**
         * @var ExceptionListener
         */
        $class=$this->constructClass();

        $exception=new ApiReturnedNoDataException('giberish');

        $responseEvent=$this->getMockBuilder(GetResponseForExceptionEvent::class)
                                ->disableOriginalConstructor()
                                ->getMock();

        $responseEvent->method('getException')->willReturn( $exception );

        /**
         * @var Response
         */
        $class->onKernelException($responseEvent);

        $this->assertEquals($response->getStatusCode(),Response::HTTP_NOT_FOUND);
    }

    /**
     * @return ExceptionListener
     */
    private function constructClass()
    {

        $twigMock=$this->getMockBuilder(\Twig_Environment::class)
                            ->disableOriginalConstructor()
                            ->getMock();

        $twigMock->method('render')->willReturn('');

        $exceptionListener= new ExceptionListener('prod',$twigMock);

        return $exceptionListener;
    }
}

但 phpoUnit 正确抛出：

1) AppBundle\Tests\Managers\ExceptionListenerTest::testnoDataExceptionTest
Error: Call to a member function getStatusCode() on null

所以我需要构造一个正确的GetResponseForExceptionEvent但是它的构造函数需要传递一个HttpKernelInterface客栈命令来构造它。所以：

是否建议模拟 HttpKernelInterface？它会破坏 class 的使用吗？
是否有更好的方法对 MyExceptionListener 进行单元测试？

Answer 1

您测试的方法将 GetResponseForExceptionEvent 作为参数。这是应该嘲笑的class。

如果您正在测试 GetResponseForExceptionEvent class（已由 Symfony 开发人员测试），HttpKernelInterface 的模拟是可以接受的。

单元测试不会测试另一个 class 内部发生的事情，只是您测试的 class 完成它的工作并调用其他 class 所需的方法。这意味着测试 MyExceptionListener 实际上是在断言 GetResponseForExceptionEvent 的方法 setResponse 是用正确的参数调用的。

Symfony 单元测试自定义事件监听器

Symfony Unit test Custom Event Listener

php

symfony

unit-testing

phpunit

symfony-3.3