Use dama/doctrine-test-bundle for proper test DB isolation

app/AppKernel.php

@@ -34,6 +34,12 @@ public function registerBundles()
             $bundles[] = new Symfony\Bundle\WebProfilerBundle\WebProfilerBundle();
             $bundles[] = new Sensio\Bundle\DistributionBundle\SensioDistributionBundle();
             $bundles[] = new Sensio\Bundle\GeneratorBundle\SensioGeneratorBundle();
+
+            if ('test' === $this->getEnvironment()) {
+                // this bundle makes it easier to work with databases in PHPUnit
+                // tests, so it's only loaded for the 'test' environment
+                $bundles[] = new DAMA\DoctrineTestBundle\DAMADoctrineTestBundle();
+            }
         }
 
         return $bundles;

app/Resources/views/admin/blog/_delete_form.html.twig

@@ -1,5 +1,5 @@
 {{ include('blog/_delete_post_confirmation.html.twig') }}
-<form action="{{ url('admin_post_delete', { id: post.id }) }}" method="post" data-confirmation="true">
+<form action="{{ url('admin_post_delete', { id: post.id }) }}" method="post" data-confirmation="true" id="delete-form">
     <input type="hidden" name="token" value="{{ csrf_token('delete') }}" />
     <input type="submit" value="{{ 'action.delete_post'|trans }}" class="btn btn-lg btn-block btn-danger" />
 </form>

composer.json

@@ -31,6 +31,7 @@
         "white-october/pagerfanta-bundle"      : "^1.0"
     },
     "require-dev": {
+        "dama/doctrine-test-bundle"            : "^1.0",
         "friendsofphp/php-cs-fixer"            : "^2.0",
         "phpunit/phpunit"                      : "^4.8 || ^5.0",
         "sensio/generator-bundle"              : "^3.0",

phpunit.xml.dist

@@ -28,4 +28,10 @@
             </exclude>
         </whitelist>
     </filter>
+
+    <listeners>
+        <!-- it begins a database transaction before every testcase and rolls it back after
+             the test finished, so tests can manipulate the database without affecting other tests -->
+        <listener class="\DAMA\DoctrineTestBundle\PHPUnit\PHPUnitStaticDbConnectionListener" />
+    </listeners>
 </phpunit>

tests/AppBundle/Controller/Admin/BlogControllerTest.php

@@ -11,6 +11,7 @@
 
 namespace Tests\AppBundle\Controller\Admin;
 
+use AppBundle\Entity\Post;
 use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
 use Symfony\Component\HttpFoundation\Response;
 
@@ -54,40 +55,69 @@ public function getUrlsForRegularUsers()
     }
 
     /**
-     * @dataProvider getUrlsForAdminUsers
+     * @return \Symfony\Bundle\FrameworkBundle\Client
      */
-    public function testAdminUsers($httpMethod, $url, $statusCode)
+    private function getAdminClient()
     {
-        $client = static::createClient([], [
+        return static::createClient([], [
             'PHP_AUTH_USER' => 'jane_admin',
             'PHP_AUTH_PW' => 'kitten',
         ]);
-
-        $client->request($httpMethod, $url);
-        $this->assertSame($statusCode, $client->getResponse()->getStatusCode());
-    }
-
-    public function getUrlsForAdminUsers()
-    {
-        yield ['GET', '/en/admin/post/', Response::HTTP_OK];
-        yield ['GET', '/en/admin/post/1', Response::HTTP_OK];
-        yield ['GET', '/en/admin/post/1/edit', Response::HTTP_OK];
-        yield ['POST', '/en/admin/post/1/delete', Response::HTTP_FOUND];
     }
 
-    public function testBackendHomepage()
+    public function testAdminBackendHomePage()
     {
-        $client = static::createClient([], [
-            'PHP_AUTH_USER' => 'jane_admin',
-            'PHP_AUTH_PW' => 'kitten',
-        ]);
+        $client = $this->getAdminClient();
 
         $crawler = $client->request('GET', '/en/admin/post/');
+        $this->assertSame(Response::HTTP_OK, $client->getResponse()->getStatusCode());
 
         $this->assertCount(
             30,
             $crawler->filter('body#admin_post_index #main tbody tr'),
             'The backend homepage displays all the available posts.'
         );
     }
+
+    /**
+     * This test changes the database contents by deleting a blog post. However,
+     * thanks to the DAMADoctrineTestBundle and its PHPUnit listener, all changes
+     * to the database are rolled back when this test completes. This means that
+     * all the application tests begin with the same database contents.
+     */
+    public function testAdminDeletePost()
+    {
+        $client = $this->getAdminClient();
+        $crawler = $client->request('GET', '/en/admin/post/1');
+        $client->submit($crawler->filter('#delete-form')->form());
+
+        $this->assertSame(Response::HTTP_FOUND, $client->getResponse()->getStatusCode());
+
+        $post = $client->getContainer()->get('doctrine')->getRepository(Post::class)->find(1);
+        $this->assertNull($post);
+    }
+
+    /**
+     * This test changes the database contents by editing a blog post. However,
+     * thanks to the DAMADoctrineTestBundle and its PHPUnit listener, all changes
+     * to the database are rolled back when this test completes. This means that
+     * all the application tests begin with the same database contents.
+     */
+    public function testAdminEditPost()
+    {
+        $newBlogPostTitle = 'Blog Post Title '.mt_rand();
+
+        $client = $this->getAdminClient();
+        $crawler = $client->request('GET', '/en/admin/post/1/edit');
+        $form = $crawler->selectButton('Save changes')->form([
+            'post[title]' => $newBlogPostTitle,
+        ]);
+        $client->submit($form);
+
+        $this->assertSame(Response::HTTP_FOUND, $client->getResponse()->getStatusCode());
+
+        /** @var Post $post */
+        $post = $client->getContainer()->get('doctrine')->getRepository(Post::class)->find(1);
+        $this->assertSame($newBlogPostTitle, $post->getTitle());
+    }
 }