Memory example

$queue2 = new DatabaseQueue($this->randomMachineName(), Database::getConnection());
    $queue2->createQueue();

    $this->runQueueTest($queue1, $queue2);
  }

  /** * Tests the Memory queue. */
  public function testMemoryQueue() {
    // Create two queues.     $queue1 = new Memory($this->randomMachineName());
    $queue1->createQueue();
    $queue2 = new Memory($this->randomMachineName());
    $queue2->createQueue();

    $this->runQueueTest($queue1, $queue2);
  }

  /** * Queues and dequeues a set of items to check the basic queue functionality. * * @param \Drupal\Core\Queue\QueueInterface $queue1 * An instantiated queue object. * @param \Drupal\Core\Queue\QueueInterface $queue2 * An instantiated queue object. */

$time = $this->prophesize('Drupal\Component\Datetime\TimeInterface');
    $time->getCurrentTime()->willReturn($this->currentTime);
    $time->getCurrentMicroTime()->willReturn(100.0);
    $time->getRequestTime()->willReturn($this->currentTime);
    \Drupal::getContainer()->set('datetime.time', $time->reveal());
    $this->assertEquals($this->currentTime, \Drupal::time()->getCurrentTime());
    $this->assertEquals($this->currentTime, \Drupal::time()->getRequestTime());

    $realQueueFactory = $this->container->get('queue');
    $queue_factory = $this->prophesize(get_class($realQueueFactory));
    $database = new DatabaseQueue('cron_queue_test_database_delay_exception', $this->connection);
    $memory = new Memory('cron_queue_test_memory_delay_exception');
    $queue_factory->get('cron_queue_test_database_delay_exception', Argument::cetera())->willReturn($database);
    $queue_factory->get('cron_queue_test_memory_delay_exception', Argument::cetera())->willReturn($memory);
    $queue_factory->get(Argument::any(), Argument::cetera())->will(function D$args) use ($realQueueFactory) {
      return $realQueueFactory->get($args[0], $args[1] ?? FALSE);
    });

    $this->container->set('queue', $queue_factory->reveal());
  }

  /** * Tests that DelayedRequeueException behaves as expected when running cron. */

// Create a queue worker definition for testing purposes.     $queue_worker = $this->randomMachineName();
    $queue_worker_definition = [
      'id' => $queue_worker,
      'cron' => [
        'time' => &$this->claimTime,
      ],
    ];

    // Create a queue instance for this queue worker.     $this->queue = new Memory($queue_worker);
    $queue_factory->get($queue_worker)->willReturn($this->queue);

    // Create a mock queue worker plugin instance based on above definition.     $queue_worker_plugin = $this->prophesize('Drupal\Core\Queue\QueueWorkerInterface');
    $queue_worker_plugin->getPluginId()->willReturn($queue_worker);
    $queue_worker_plugin->getPluginDefinition()->willReturn($queue_worker_definition);
    $queue_worker_plugin->processItem('Complete')->willReturn();
    $queue_worker_plugin->processItem('Exception')->willThrow(\Exception::class);
    $queue_worker_plugin->processItem('DelayedRequeueException')->willThrow(DelayedRequeueException::class);
    $queue_worker_plugin->processItem('SuspendQueueException')->willThrow(SuspendQueueException::class);
    // 'RequeueException' would normally result in an infinite loop.