N°2651 rollback gitignore for lib tests dirs

Too dangerous ! We'll work properly on this but for 2.8

lib/symfony/dependency-injection/Tests/Compiler/CheckReferenceValidityPassTest.php

@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\DependencyInjection\Tests\Compiler;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\Compiler\CheckReferenceValidityPass;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Reference;
+
+class CheckReferenceValidityPassTest extends TestCase
+{
+    public function testProcessDetectsReferenceToAbstractDefinition()
+    {
+        $this->expectException('RuntimeException');
+        $container = new ContainerBuilder();
+
+        $container->register('a')->setAbstract(true);
+        $container->register('b')->addArgument(new Reference('a'));
+
+        $this->process($container);
+    }
+
+    public function testProcess()
+    {
+        $container = new ContainerBuilder();
+        $container->register('a')->addArgument(new Reference('b'));
+        $container->register('b');
+
+        $this->process($container);
+
+        $this->addToAssertionCount(1);
+    }
+
+    protected function process(ContainerBuilder $container)
+    {
+        $pass = new CheckReferenceValidityPass();
+        $pass->process($container);
+    }
+}