Add correct implementation of DI

queue_order.info.yml

-name: Queue order [no UI]
+name: "Queue order"
 type: module
-description: "Provide api to control queue order execution"
-package: System utility
+description: "Provide basic functionality to control queue order execution"
+package: "System utility"
 core: 8.x
 dependencies:
-  - drupal:system (>= 8.2.0)
+  - drupal:system

src/Queue/QueueWorkerManager.php

@@ -3,6 +3,9 @@
 namespace Drupal\queue_order\Queue;
 
 use Drupal\Component\Utility\SortArray;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Queue\QueueWorkerManager as CoreQueueWorkerManager;
 
 /**
@@ -12,12 +15,37 @@ use Drupal\Core\Queue\QueueWorkerManager as CoreQueueWorkerManager;
  */
 class QueueWorkerManager extends CoreQueueWorkerManager {
 
+  /**
+   * The module config.
+   *
+   * @var \Drupal\Core\Config\ImmutableConfig
+   */
+  protected $config;
+
+  /**
+   * Constructs an QueueWorkerManager object.
+   *
+   * @param \Traversable $namespaces
+   *   An object that implements \Traversable which contains the root paths
+   *   keyed by the corresponding namespace to look for plugin implementations.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
+   *   Cache backend instance to use.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
+   *   The module configs.
+   */
+  public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler, ConfigFactoryInterface $config) {
+    parent::__construct($namespaces, $cache_backend, $module_handler);
+    $this->config = $config->get('queue_order.settings');
+  }
+
   /**
    * {@inheritdoc}
    */
   public function getDefinitions() {
     $definitions = parent::getDefinitions();
-    $weight = \Drupal::config('queue_order.settings')->get('order');
+    $weight = $this->config->get('order');
     $weight = empty($weight) ? [] : $weight;
     foreach ($definitions as $key => &$definition) {
       $definition['weight'] = empty($weight[$key]) ? 0 : intval($weight[$key]);

src/QueueOrderServiceProvider.php

@@ -5,6 +5,7 @@ namespace Drupal\queue_order;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\DependencyInjection\ServiceProviderBase;
 use Drupal\queue_order\Queue\QueueWorkerManager;
+use Symfony\Component\DependencyInjection\Reference;
 
 /**
  * Class QueueOrderServiceProvider.
@@ -18,8 +19,9 @@ class QueueOrderServiceProvider extends ServiceProviderBase {
    */
   public function alter(ContainerBuilder $container) {
     if ($container->has('plugin.manager.queue_worker')) {
-      $container->getDefinition('plugin.manager.queue_worker')
-        ->setClass(QueueWorkerManager::class);
+      $plugin_manager = $container->getDefinition('plugin.manager.queue_worker');
+      $plugin_manager->setClass(QueueWorkerManager::class);
+      $plugin_manager->addArgument(new Reference('config.factory'));
     }
   }