Running cron queues that use a derivative is broken

Problem/Motivation

In #3198868: Add delay to queue suspend the code for running cron queues has changed. This caused that queue workers that use a deriver cause a fatal error on cron runs.

An error message like the following can occur when running cron:

Drupal\Component\Plugin\Exception\PluginNotFoundException: The "feeds_feed_refresh" plugin does not exist. Valid plugin IDs for Drupal\Core\Queue\QueueWorkerManager are: feeds_feed_refresh:article, feeds_feed_refresh:csv, feeds_feed_refresh:issue, feeds_feed_refresh:products, feeds_feed_refresh:variations, feeds_feed_refresh:xml in Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition() (line 53 of core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php).

This is how a queue definition from the Feeds module looks like:

'feeds_feed_refresh:article' => array (6) [
        'title' => Drupal\Core\StringTranslation\TranslatableMarkup (5) (
            protected 'string' -> string (30) "Feed refresh: @feed_type_label"
            protected 'arguments' -> array (1) [
                '@feed_type_label' => string (7) "Article"
            ]
            protected 'translatedMarkup' -> null
            protected 'options' -> array (0) []
            protected 'stringTranslation' -> null
        )
        'id' => string (18) "feeds_feed_refresh"
        'cron' => array (1) [
            'time' => integer 60
        ]
        'deriver' => string (46) "Drupal\feeds\Plugin\Derivative\FeedQueueWorker"
        'class' => string (43) "Drupal\feeds\Plugin\QueueWorker\FeedRefresh"
        'provider' => string (5) "feeds"
    ]

The issue is that \Drupal\Core\Cron now picks the queue name from $queue_info['id'], while it previously took the key from the queue array. By my understanding 'id' in the example above is the base plugin ID. And the key on the array is the derivative plugin ID.

Steps to reproduce

1. Implement a QueueWorker plugin that makes use of a deriver and that uses cron (see code example below).
2. Implement the deriver plugin (see code example below).
3. Create an item on the queue (see code example below).
4. Run cron.

Example QueueWorker plugin:

namespace Drupal\mymodule\Plugin\QueueWorker;

use Drupal\Core\Queue\QueueWorkerBase;

/**
 * A queue worker.
 *
 * @QueueWorker(
 *   id = "myqueue",
 *   title = @Translation("My Queue"),
 *   cron = {"time" = 60},
 *   deriver = "Drupal\mymodule\Plugin\Derivative\QueueWorkerDerivative"
 * )
 */
class MyQueueWorker extends QueueWorkerBase {

  /**
   * {@inheritdoc}
   */
  public function processItem($data) {}

}

Example deriver:

namespace Drupal\mymodule\Plugin\Derivative;

use Drupal\Component\Plugin\Derivative\DeriverBase;

/**
 * Provides separate queue works.
 *
 * @see \Drupal\mymodule\Plugin\QueueWorker\MyQueueWorker
 */
class QueueWorkerDerivative extends DeriverBase {

  /**
   * {@inheritdoc}
   */
  public function getDerivativeDefinitions($base_plugin_definition) {
    $example_data = [
      'foo' => 'Foo',
      'bar' => 'Bar',
    ];

    $derivatives = [];
    foreach ($example_data as $key => $label) {
      $derivatives[$key] = [
        'title' => strtr('My Queue: @label', [
          '@label' => $label,
        ]),
      ] + $base_plugin_definition;
    }

    return $derivatives;
  }

}

Create an item on the queue:

\Drupal::service('queue')->get('myqueue:foo')
  ->createItem([]);

Proposed resolution

Change the implementation of Drupal\Core\Cron::processQueues() so that the queue name is taken from the key of the queues array instead of picking the 'id' property directly.

Remaining tasks

1. Confirm that this is a bug (and not a misunderstanding of how derivatives should be implemented).
2. Implement the proposed resolution.
3. Add a test that demonstrates the bug. Probably the example code from above should be put in a test module in core/modules/system/tests/modules.

User interface changes

API changes

Data model changes

Release notes snippet