Add an auto_alias compiler pass

src/Symfony/Component/DependencyInjection/Compiler/AutoAliasServicePass.php

@@ -0,0 +1,41 @@
+<?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\Compiler;
+
+use Symfony\Component\DependencyInjection\Alias;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
+
+/**
+ * Sets a service to be an alias of another one, given a format pattern.
+ */
+class AutoAliasServicePass implements CompilerPassInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function process(ContainerBuilder $container)
+    {
+        foreach ($container->findTaggedServiceIds('auto_alias') as $serviceId => $tags) {
+            foreach ($tags as $tag) {
+                if (!isset($tag['format'])) {
+                    throw new InvalidArgumentException(sprintf('Missing tag information "format" on auto_alias service "%s".', $serviceId));
+                }
+
+                $aliasId = $container->getParameterBag()->resolveValue($tag['format']);
+                if ($container->hasDefinition($aliasId) || $container->hasAlias($aliasId)) {
+                    $container->setAlias($serviceId, new Alias($aliasId));
+                }
+            }
+        }
+    }
+}

src/Symfony/Component/DependencyInjection/Tests/Compiler/AutoAliasServicePassTest.php

@@ -0,0 +1,103 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Compiler;
+
+use Symfony\Component\DependencyInjection\Compiler\AutoAliasServicePass;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+class AutoAliasServicePassTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\ParameterNotFoundException
+     */
+    public function testProcessWithMissingParameter()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('example')
+          ->addTag('auto_alias', array('format' => '%non_existing%.example'));
+
+        $pass = new AutoAliasServicePass();
+        $pass->process($container);
+    }
+
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\InvalidArgumentException
+     */
+    public function testProcessWithMissingFormat()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('example')
+          ->addTag('auto_alias', array());
+        $container->setParameter('existing', 'mysql');
+
+        $pass = new AutoAliasServicePass();
+        $pass->process($container);
+    }
+
+    public function testProcessWithNonExistingAlias()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('example', 'Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassDefault')
+          ->addTag('auto_alias', array('format' => '%existing%.example'));
+        $container->setParameter('existing', 'mysql');
+
+        $pass = new AutoAliasServicePass();
+        $pass->process($container);
+
+        $this->assertEquals('Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassDefault', $container->getDefinition('example')->getClass());
+        $this->assertInstanceOf('Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassDefault', $container->get('example'));
+    }
+
+    public function testProcessWithExistingAlias()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('example', 'Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassDefault')
+          ->addTag('auto_alias', array('format' => '%existing%.example'));
+
+        $container->register('mysql.example', 'Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassMysql');
+        $container->setParameter('existing', 'mysql');
+
+        $pass = new AutoAliasServicePass();
+        $pass->process($container);
+
+        $this->assertTrue($container->hasAlias('example'));
+        $this->assertEquals('mysql.example', $container->getAlias('example'));
+        $this->assertInstanceOf('Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassMysql', $container->get('example'));
+    }
+
+    public function testProcessWithManualAlias()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('example', 'Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassDefault')
+          ->addTag('auto_alias', array('format' => '%existing%.example'));
+
+        $container->register('mysql.example', 'Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassMysql');
+        $container->register('mariadb.example', 'Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassMariadb');
+        $container->setAlias('example', 'mariadb.example');
+        $container->setParameter('existing', 'mysql');
+
+        $pass = new AutoAliasServicePass();
+        $pass->process($container);
+
+        $this->assertTrue($container->hasAlias('example'));
+        $this->assertEquals('mariadb.example', $container->getAlias('example'));
+        $this->assertInstanceOf('Symfony\Component\DependencyInjection\Tests\Compiler\ServiceClassMariaDb', $container->get('example'));
+    }
+}
+
+class ServiceClassDefault
+{
+}
+
+class ServiceClassMysql extends ServiceClassDefault
+{
+}
+
+class ServiceClassMariaDb extends ServiceClassMysql
+{
+}