Fixed empty resolved service name

Author: lookyman

src/Rules/ContainerInterfaceUnknownServiceRule.php

@@ -12,7 +12,6 @@
 use PhpParser\Node;
 use PhpParser\Node\Arg;
 use PhpParser\Node\Expr\MethodCall;
-use PhpParser\Node\Expr\Variable;
 
 final class ContainerInterfaceUnknownServiceRule implements Rule
 {
@@ -42,11 +41,13 @@ public function processNode(Node $node, Scope $scope): array
 			if (($isInstanceOfController || $isContainerInterface)
 				&& isset($node->args[0])
 				&& $node->args[0] instanceof Arg
-				&& !$node->args[0]->value instanceof Variable
 			) {
 				$service = $this->serviceMap->getServiceFromNode($node->args[0]->value);
 				if ($service === \null) {
-					return [\sprintf('Service "%s" is not registered in the container.', ServiceMap::getServiceIdFromNode($node->args[0]->value))];
+					$serviceId = ServiceMap::getServiceIdFromNode($node->args[0]->value);
+					if ($serviceId !== null) {
+						return [\sprintf('Service "%s" is not registered in the container.', $serviceId)];
+					}
 				}
 			}
 		}

tests/Rules/data/ExampleController.php

@@ -27,4 +27,10 @@ public function getVariableService(string $serviceKey)
 		$service->noMethod();
 	}
 
+	public function getConcatenatedService(string $serviceKey)
+	{
+		$service = $this->get('service.' . self::class);
+		$service->noMethod();
+	}
+
 }