使用assertEquals测试Doctrine2实体会导致致命的内存不足错误

我有一个PHPUnit测试，它使用Doctrine2自定义存储库和Doctrine Fixtures。我想测试一个查询是否从我的fixture中返回了一个预期的实体。

但当我尝试$this->assertEquals($expectedEntity, $result);时，我得到了Fatal error: out of memory。我猜它正在反复出现在所有的关系和实体经理之类的人身上。

有没有一个好的方法来检验这种平等？我应该只对实体的ID进行assertEquals吗？

编辑：这是测试代码

<?php
use Liip'FunctionalTestBundle'Test'WebTestCase;
class AbstractRepositoryTestCase extends WebTestCase
{
    /**
     * @var Doctrine'ORM'EntityRepository 
     */
    protected $repo;
    /**
     * @var Doctrine'Common'DataFixtures'Executor'AbstractExecutor
     */
    protected $fixtureExecutor;
    /**
     * @var string Which repository to load, overriden by derived class
     */
    protected $repoName;
    /**
     * @var array Fixture classes to load on setup
     */
    protected $fixtures = array();
    public function setUp()
    {
        $kernel = static::createKernel();
        $this->repo = $kernel->boot();
        $this->repo = $kernel->getContainer()
                             ->get('doctrine.orm.entity_manager')
                             ->getRepository($this->repoName);
        $this->fixtureExecutor = $this->loadFixtures($this->getFixtures());
    }
    public function getFixtures()
    {
        return $this->fixtures;
    }
}
class ArticleRepositoryTest extends AbstractRepositoryTestCase
{
    /**
     * @var string Which repository to load, overriden by derived class
     */
    protected $repoName = 'MyMainBundle:Article';
    /**
     * @var array Fixture classes to load on setup
     */
    protected $fixtures = array(
        'My'MainBundle'DataFixtures'ORM'LoadUserData',
        'My'MainBundle'DataFixtures'ORM'LoadArticleData',
        'My'MainBundle'DataFixtures'ORM'LoadFeedsData',
        'My'MainBundle'DataFixtures'ORM'LoadFeedDataData',
        'My'MainBundle'DataFixtures'ORM'LoadUserReadArticleData',
    );
    public function testGetNextArticle_ExpectCorrect()
    {
        /** @var Doctrine'Common'DataFixtures'ReferenceRepository **/
        $refRepo = $this->fixtureExecutor->getReferenceRepository();
        /** @var FeedStream'MainBundle'Entity'Article **/
        $curr = $refRepo->getReference('feed-1-article-3');
        $expected = $refRepo->getReference('feed-1-article-2');
        $expected2 = $refRepo->getReference('feed-1-article-1');
        $next = $this->repo->getNextArticle($curr->getFeed()->getId(), $curr);
        $this->assertNotNull($next);
        // this is the part that doesn't work
        $this->assertEquals($expected, $next);
        // this is the code I've used instead
        $this->assertEquals($expected->getId(), $next->getId());
    }
}

以下是实体（省略getter/setter以节省空间）

<?php
namespace My'MainBundle'Entity;
use Doctrine'ORM'Mapping as ORM;
/**
 * My'MainBundle'Entity'Article
 *
 * @ORM'Table(name="articles", uniqueConstraints={
 *   @ORM'UniqueConstraint(name="feed_guid", columns={"feed_id", "guid"}),
 *   @ORM'UniqueConstraint(name="article_slug_unique", columns={"feed_id", "slug"})
 * })
 * @ORM'Entity(repositoryClass="My'MainBundle'Repository'ArticleRepository")
 */
class Article
{
    /**
     * @var integer $id
     *
     * @ORM'Column(name="id", type="integer", nullable=false)
     * @ORM'Id
     * @ORM'GeneratedValue(strategy="IDENTITY")
     */
    private $id;
    /**
     * @var string $guid
     *
     * @ORM'Column(name="guid", type="string", length=255, nullable=false)
     */
    private $guid;
    /**
     * @var string $title
     *
     * @ORM'Column(name="title", type="string", length=255, nullable=false)
     */
    private $title;
    /**
     * @var datetime $pubDate
     *
     * @ORM'Column(name="pub_date", type="datetime", nullable=true)
     */
    private $pubDate;
    /**
     * @var text $summary
     *
     * @ORM'Column(name="summary", type="text", nullable=true)
     */
    private $summary;
    /**
     * @var text $content
     *
     * @ORM'Column(name="content", type="text", nullable=false)
     */
    private $content;
    /**
     * @var string $sourceUrl
     *
     * @ORM'Column(name="source_url", type="string", length=255, nullable=true)
     */
    private $sourceUrl;
    /**
     * @var string $commentUrl
     *
     * @ORM'Column(name="comment_url", type="string", length=255, nullable=true)
     */
    private $commentUrl;
    /**
     * @var string $slug
     *
     * @ORM'Column(name="slug", type="string", length=64, nullable=false)
     */
    private $slug;
    /**
     * @var string $thumbnailFile
     *
     * @ORM'Column(name="thumbnail_file", type="string", length=64, nullable=true)
     */
    private $thumbnailFile;
    /**
     * @var My'MainBundle'Entity'ArticleEnclosure
     *
     * @ORM'ManyToOne(targetEntity="My'MainBundle'Entity'ArticleEnclosure")
     * @ORM'JoinColumns({
     *   @ORM'JoinColumn(name="thumbnail_enclosure_id", referencedColumnName="id")
     * })
     */
    private $thumbnailEnclosure;
    /**
     * @var My'MainBundle'Entity'ArticleImageScrape
     *
     * @ORM'ManyToOne(targetEntity="My'MainBundle'Entity'ArticleImageScrape")
     * @ORM'JoinColumns({
     *   @ORM'JoinColumn(name="thumbnail_scrape_id", referencedColumnName="id", unique=false)
     * })
     */
    private $thumbnailScrape;
    /**
     * @var My'MainBundle'Entity'ArticleBitly
     *
     * @ORM'OneToOne(targetEntity="My'MainBundle'Entity'ArticleBitly", mappedBy="article", orphanRemoval=true)
     */
    private $bitly;
    /**
     * @var My'MainBundle'Entity'ArticleEnclosure
     *
     * @ORM'OneToMany(targetEntity="My'MainBundle'Entity'ArticleEnclosure", mappedBy="article", orphanRemoval=true)
     */
    private $enclosures;
    /**
     * @var My'MainBundle'Entity'ArticleImageScrape
     *
     * @ORM'OneToMany(targetEntity="My'MainBundle'Entity'ArticleImageScrape", mappedBy="article", orphanRemoval=true)
     */
    private $scrapes;
    /**
     * @var My'MainBundle'Entity'ArticleLink
     *
     * @ORM'OneToMany(targetEntity="My'MainBundle'Entity'ArticleLink", mappedBy="article", orphanRemoval=true)
     */
    private $links;
    /**
     * @var My'MainBundle'Entity'Feed
     *
     * @ORM'ManyToOne(targetEntity="My'MainBundle'Entity'Feed", inversedBy="articles")
     * @ORM'JoinColumns({
     *   @ORM'JoinColumn(name="feed_id", referencedColumnName="id", nullable=false)
     * })
     */
    private $feed;
    /**
     * @var My'MainBundle'Entity'ArticleAuthor
     *
     * @ORM'ManyToOne(targetEntity="My'MainBundle'Entity'ArticleAuthor", inversedBy="articles")
     * @ORM'JoinColumns({
     *   @ORM'JoinColumn(name="author_id", referencedColumnName="id")
     * })
     */
    private $author;
    public function __construct()
    {
        $this->links = new 'Doctrine'Common'Collections'ArrayCollection();
    }
}