feature #27062 [SecurityBundle] Register a UserProviderInterface al…

…ias if one provider only (sroze)

This PR was merged into the 4.1-dev branch.

Discussion
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[SecurityBundle] Register a `UserProviderInterface` alias if one provider only

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | ø
| License       | MIT
| Doc PR        | ø

When using only one user provider (as in most of the cases), it will register an alias for the `UserProviderInterface` interface and allow auto-wiring of it.

Commits
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4cbddd8 Register a `UserProviderInterface` alias if one provider only

src/Symfony/Bundle/SecurityBundle/DependencyInjection/SecurityExtension.php

@@ -28,6 +28,7 @@
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\Security\Core\Authorization\Voter\VoterInterface;
 use Symfony\Component\Security\Core\Encoder\Argon2iPasswordEncoder;
+use Symfony\Component\Security\Core\User\UserProviderInterface;
 use Symfony\Component\Security\Http\Controller\UserValueResolver;
 
 /**
@@ -180,6 +181,10 @@ private function createFirewalls($config, ContainerBuilder $container)
         $arguments[1] = new IteratorArgument($userProviders);
         $contextListenerDefinition->setArguments($arguments);
 
+        if (1 === \count($providerIds)) {
+            $container->setAlias(UserProviderInterface::class, current($providerIds));
+        }
+
         $customUserChecker = false;
 
         // load firewall map

src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/SecurityExtensionTest.php

@@ -19,6 +19,7 @@
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\ExpressionLanguage\Expression;
+use Symfony\Component\Security\Core\User\UserProviderInterface;
 
 class SecurityExtensionTest extends TestCase
 {
@@ -270,6 +271,51 @@ public function testRemovesExpressionCacheWarmerDefinitionIfNoExpressions()
         $this->assertFalse($container->hasDefinition('security.cache_warmer.expression'));
     }
 
+    public function testRegisterTheUserProviderAlias()
+    {
+        $container = $this->getRawContainer();
+
+        $container->loadFromExtension('security', array(
+            'providers' => array(
+                'default' => array('id' => 'foo'),
+            ),
+
+            'firewalls' => array(
+                'some_firewall' => array(
+                    'pattern' => '/.*',
+                    'http_basic' => null,
+                ),
+            ),
+        ));
+
+        $container->compile();
+
+        $this->assertTrue($container->hasAlias(UserProviderInterface::class));
+    }
+
+    public function testDoNotRegisterTheUserProviderAliasWithMultipleProviders()
+    {
+        $container = $this->getRawContainer();
+
+        $container->loadFromExtension('security', array(
+            'providers' => array(
+                'first' => array('id' => 'foo'),
+                'second' => array('id' => 'bar'),
+            ),
+
+            'firewalls' => array(
+                'some_firewall' => array(
+                    'pattern' => '/.*',
+                    'http_basic' => array('provider' => 'second'),
+                ),
+            ),
+        ));
+
+        $container->compile();
+
+        $this->assertFalse($container->has(UserProviderInterface::class));
+    }
+
     protected function getRawContainer()
     {
         $container = new ContainerBuilder();