fix: #3480025 Implement ::garbageCollection in the memory backend

   * {@inheritdoc}

   */

  public function garbageCollection() {

    $requestTime = $this->time->getRequestTime();

    $this->cache = array_filter($this->cache, function ($item) use ($requestTime) {

      return $item->expire == Cache::PERMANENT || $item->expire >= $requestTime;

    });

  }

  /**

<?php

declare(strict_types=1);

namespace Drupal\Tests\Core\Cache;

use Drupal\Component\Datetime\TimeInterface;

use Drupal\Core\Cache\Cache;

use Drupal\Core\Cache\MemoryBackend;

use Drupal\Tests\UnitTestCase;

use PHPUnit\Framework\Attributes\CoversClass;

use PHPUnit\Framework\Attributes\Group;

/**

 * Tests the MemoryBackend cache.

 */

#[CoversClass(MemoryBackend::class)]

#[Group('Cache')]

class MemoryBackendTest extends UnitTestCase {

  /**

   * Tests that expired cache items are removed from memory.

   *

   * @legacy-covers ::garbageCollection

   */

  public function testGarbageCollection(): void {

    $time = $this->createMock(TimeInterface::class);

    $time->expects($this->any())

      ->method('getRequestTime')

      ->willReturn(100);

    $backend = new MemoryBackend($time);

    // Set a cache item that is expired.

    $backend->set('foo', 0, 10);

    // Set a cache item that is not expired.

    $backend->set('bar', 1, 200);

    // Set a permanent cache item.

    $backend->set('baz', 2, Cache::PERMANENT);

    // Verify that the cache entries were set.

    $this->assertInstanceOf(\stdClass::class, $backend->get('foo', TRUE));

    $this->assertInstanceOf(\stdClass::class, $backend->get('bar', TRUE));

    $this->assertInstanceOf(\stdClass::class, $backend->get('baz', TRUE));

    $backend->garbageCollection();

    // Verify that the cache entries were cleared or retained correctly.

    $this->assertFalse($backend->get('foo', TRUE));

    $this->assertInstanceOf(\stdClass::class, $backend->get('bar', TRUE));

    $this->assertInstanceOf(\stdClass::class, $backend->get('baz', TRUE));

  }

}