Symfony2 单元测试服务

Question

我对 symfony 还是很陌生，但真的很喜欢它。

我正处于成功创建和设置服务的阶段，该服务本身使用 2 个依赖项:

• 一个返回 json 数据的数据 API(这是一个单独的库，它我已经作为一项服务实现并附带了自己的单元测试)。
• Doctrine 实体经理。

该服务使用 api 提取所需的数据，然后遍历数据并检查数据是否已经存在，如果存在则更新现有实体并持久化它，否则它创建一个新实体分配数据和坚持下去。

我现在需要为此编写一个单元测试，我没有仅使用 symfony2 教程中的 PHPUnit，这些教程正在测试来自 Controller 的响应。

我如何着手为此服务编写单元测试？特别是模拟我通常从 api 中提取的数据。然后检查条目是否需要更新或创建？

代码示例会非常有用，因此我可以将其用作模板来为我创建的其他类似服务创建测试。

这是我要测试的服务:

<?php

namespace FantasyPro\DataBundle\DataManager;

use Doctrine\ORM\EntityManager;
use FantasyDataAPI\Client;
use FantasyPro\DataBundle\Entity\Stadium;

class StadiumParser {
    /**
     * @var EntityManager $em
     */
    private  $em;
    /**
     * @var Client $client
     */
    private $client;

    public function __construct( EntityManager $em, Client $client) {
        $this->em = $em;
        $this->client = $client;
    }

    /**
     * @return array
     */
    public Function parseData(){

        //var_dump($this);
        $stadiumData = $this->client->Stadiums();
        //var_dump($stadiumData);
        //get the Repo
        $repo = $this->em->getRepository('DataBundle:Stadium');

        $log = array();

        foreach ($stadiumData as $stadium) {
            // Get the current stadium in the list from the database
            $criteria = array( 'stadiumID' => $stadium['StadiumID'] );
            $currentStadium = $repo->FindOneBy( $criteria );

            if ( ! $currentStadium) {
                $currentStadium = new Stadium(); //no stadium with the StadiumID exists so create a new stadium

                $logData = [
                    'action'   => 'Added Stadium',
                    'itemID'   => $stadium['StadiumID'],
                    'itemName' => $stadium['Name']
                ];
                $log[] = $logData;
            } else {
                $logData = [
                    'action'   => 'Updated Stadium',
                    'itemID'   => $stadium['StadiumID'],
                    'itemName' => $stadium['Name']
                ];
                $log[] = $logData;
            }
            $currentStadium->setStadiumID( $stadium['StadiumID'] );
            $currentStadium->setName( $stadium['Name'] );
            $currentStadium->setCity( $stadium['City'] );
            $currentStadium->setState( $stadium['State'] );
            $currentStadium->setCountry( $stadium['Country'] );
            $currentStadium->setCapacity( $stadium['Capacity'] );
            $currentStadium->setPlayingSurface( $stadium['PlayingSurface'] );
            $this->em->persist( $currentStadium );
        }
        $this->em->flush();
        return $log;
    }
}

****** 更新 *******阅读 ilpaijin 的回答后。

我已经简化了服务，所以它不再返回日志，我最初有这个，所以我可以通过将日志发送到我的 Controller 中的 Twig 模板来检查添加了什么，我最终计划让它运行一个命令，因此我可以通过 cron 作业运行它，因此不需要日志位。

我现在正在我的构造中设置实体，因为我不知道如何将实体作为注入(inject)的依赖项传递。 现在使用 createNewStadium() 方法获取一个新实体。

更新后的服务:

namespace FantasyPro\DataBundle\DataManager;

use Doctrine\ORM\EntityManager;
use FantasyDataAPI\Client;
use FantasyPro\DataBundle\Entity\Stadium;

class StadiumParser {
    /**
     * @var EntityManager $em
     */
    private  $em;
    /**
     * @var Client $client
     */
    private $client;
    /**
     * @var Stadium Stadium
     */
    private $stadium;

    public function __construct( EntityManager $em, Client $client) {
        $this->em = $em;
        $this->client = $client;
    }

    /**
     * Gets a list of stadiums using $this->client->Stadiums.
     * loops through returned stadiums and persists them
     * when loop has finished flush them to the db
     */
    public Function parseData(){
        $data = $this->client->Stadiums();
        //get the Repo
        $repo = $this->em->getRepository('DataBundle:Stadium');

        foreach ($data as $item) {
            // Get the current stadium in the list
            $criteria = array( 'stadiumID' => $item['StadiumID'] );
            $currentStadium = $repo->FindOneBy( $criteria );

            if ( ! $currentStadium) {
                $currentStadium = $this->createNewStadium; //no stadium with the StadiumID use the new stadium entity
            }
            $currentStadium->setStadiumID( $item['StadiumID'] );
            $currentStadium->setName( $item['Name'] );
            $currentStadium->setCity( $item['City'] );
            $currentStadium->setState( $item['State'] );
            $currentStadium->setCountry( $item['Country'] );
            $currentStadium->setCapacity( $item['Capacity'] );
            $currentStadium->setPlayingSurface( $item['PlayingSurface'] );
            $this->em->persist( $currentStadium );
        }
        $this->em->flush();
    }

    // Adding this new method gives you the ability to mock this dependency  when testing  
    private function createNewStadium()
    {
        return new Stadium();
    }
}

Answer 1

您基本上需要的是使用所谓的“Test doubles”对服务进行单元测试。

这意味着您应该模拟您的服务所具有的依赖关系，这样您就可以仅测试孤立的服务而无需真正依赖依赖项，而只能使用它们的模拟版本，使用硬编码的值或行为。

基于您的实际实现的真实示例是不可能的，因为您有紧密耦合的部门，如 $currentStadium = new Stadium();。您应该在构造函数中或通过 getter/setter 传递像这样的 dep，以便能够在单元测试时模拟它。

一旦完成，一个非常具有指示性的示例将是:

// class StadiumParser revisited and simplified
class StadiumParser 
{
    private $client;

    public function __construct(Client $client) 
    {
        $this->client = $client;
    }

    public function parseData()
    {
        $stadiumData = $this->client->Stadiums();

        // do something with the repo

        $log = array();

        foreach ($stadiumData as $stadium) {
            $logData = [
                'action'   => 'Added Stadium',
                'itemID'   => $stadium['StadiumID'],
                'itemName' => $stadium['Name']
            ];
            $log[] = $logData;
        } 

        // do something else with Doctrine

        return $log;
    }
}

和测试

// StadiumParser Unit Test
class StadiumParserTest extends PHPUnit_Framework_TestCase 
{
    public function testItParseDataAndReturnTheLog()
    {
        $client = $this->getMock('FantasyDataAPI\Client');

        // since you class is returning a log array, we mock it here
        $expectedLog = array(
            array(
                'action'   => 'Added Stadium',
                'itemID'   => $stadium['StadiumID'],
                'itemName' => $stadium['Name']
            )
        );

        // this is the mocked or test double part. 
        // We only need this method return something without really calling it
        // So we mock it and we hardcode the expected return value
        $stadiumData = array(
            array(
                "StadiumID" => 1,
                "Name" => "aStadiumName"
            )
        );

        $client->expects($this->once())
            ->method('Stadiums')
            ->will($this->returnValue($stadiumData));

        $stadiumParser = new StadiumParser($client);

        $this->assertEquals($expectedLog, $stadiumParser->parseData());
    }
}

我自愿省略了 EntityManager 部分，因为我想你应该看看与 how to unit test code interacting with the database 相关的 Symfony 文档

---

-----编辑2-----

是的，他是对的，你不应该。想到的一种可能方法是在 protected /私有(private)方法中提取实体的创建。像这样的东西:

// class StadiumParser
public Function parseData()
{
    ...

    foreach ($stadiumData as $stadium) {
        ...

        if ( ! $currentStadium) {
            $currentStadium = $this->createNewStadium();
        ...
}

// Adding this new method gives you the ability to mock this dependency when testing  
private function createNewStadium()
{
    return new Stadium();
}

---

-----编辑3-----

我想向您推荐另一种方法。如果 Stadium 实体在不同的服务或相同的不同部分中需要，这可能是一个更好的选择。我提议的是 Builder模式但一个Factory也可以在这里选择。浏览一下它们的差异。正如您所看到的，这从方法中提取了一些代码，更好地分配类之间的责任，让您和您的团队成员更清晰、更容易阅读。而且您已经知道如何在测试时模拟它。

class StadiumParser 
{
    private  $stadiumBuilder;
    ...

    public function __construct( StadiumBuilder $builder, ...) {
        $this->stadiumBuilder = $stadiumBuilder;
        ...
    }

    public Function parseData()
    {
        ...

        foreach ($stadiumData as $stadium) {
            ...
            $currentStadium = $repo->FindOneBy( $criteria );

            if ( ! $currentStadium) {
                $currentStadium = $this->stadiumBuilder->build($currentStadium, $stadium);
            }

            $this->em->persist($currentStadium);
            ...

在某处你有这个新的 Builder 返回一个 Stadium 实例。这样，您的 StadiumParser 服务就不再与实体耦合，而 StadiumBuilder 就是它。逻辑是这样的:

// StadiumBuilder class

namespace ???

use FantasyPro\DataBundle\Entity\Stadium;

class StadiumBuilder 
{
    // depending on the needs but this should also has a different name
    // like buildBasic or buildFull or buildBlaBlaBla or buildTest 
    public function build($currentStadium = null, $stadium)
    {
        if (!$currentStadium) {
            $currentStadium = new Stadium();
        }

        $currentStadium->setStadiumID( $stadium['StadiumID'] );
        $currentStadium->setName( $stadium['Name'] );
        $currentStadium->setCity( $stadium['City'] );
        $currentStadium->setState( $stadium['State'] );
        $currentStadium->setCountry( $stadium['Country'] );
        $currentStadium->setCapacity( $stadium['Capacity'] );
        $currentStadium->setPlayingSurface( $stadium['PlayingSurface'] );

        return $currentStadium; 
    }
}