Ignore ContainerBagInterface in ContainerInterfaceUnknownServiceRule

src/Rules/Symfony/ContainerInterfaceUnknownServiceRule.php

@@ -55,6 +55,11 @@ public function processNode(Node $node, Scope $scope): array
 		}
 
 		$argType = $scope->getType($node->var);
+		$isContainerBagType = (new ObjectType('Symfony\Component\DependencyInjection\ParameterBag\ContainerBagInterface'))->isSuperTypeOf($argType);
+		if ($isContainerBagType->yes()) {
+			return [];
+		}
+
 		$isControllerType = (new ObjectType('Symfony\Bundle\FrameworkBundle\Controller\Controller'))->isSuperTypeOf($argType);
 		$isAbstractControllerType = (new ObjectType('Symfony\Bundle\FrameworkBundle\Controller\AbstractController'))->isSuperTypeOf($argType);
 		$isContainerType = (new ObjectType('Symfony\Component\DependencyInjection\ContainerInterface'))->isSuperTypeOf($argType);

tests/Rules/Symfony/ContainerInterfaceUnknownServiceRuleTest.php

@@ -68,4 +68,18 @@ public function testGetPrivateServiceInAbstractController(): void
 		);
 	}
 
+	public function testGetPrivateServiceInLegacyServiceSubscriber(): void
+	{
+		if (!interface_exists('Symfony\Contracts\Service\ServiceSubscriberInterface')) {
+			self::markTestSkipped('The test needs Symfony\Contracts\Service\ServiceSubscriberInterface class.');
+		}
+
+		$this->analyse(
+			[
+				__DIR__ . '/ExampleServiceSubscriber.php',
+			],
+			[]
+		);
+	}
+
 }

tests/Rules/Symfony/ExampleServiceSubscriber.php

@@ -12,6 +12,13 @@ public function privateService(): void
 		$this->get('private');
 	}
 
+	public function containerParameter(): void
+	{
+		/** @var \Symfony\Component\DependencyInjection\ParameterBag\ContainerBag $containerBag */
+		$containerBag = doFoo();
+		$containerBag->get('parameter_name');
+	}
+
 	/**
 	 * @return string[]
 	 */