class CachedStorageTest

class CachedStorageTest extends UnitTestCase {
  
  /**
   * @var \Drupal\Core\Cache\CacheFactoryInterface|\PHPUnit\Framework\MockObject\MockObject
   */
  protected $cacheFactory;
  
  /**
   * Tests listAll static cache.
   */
  public function testListAllStaticCache() {
    $prefix = __FUNCTION__;
    $storage = $this->createMock('Drupal\\Core\\Config\\StorageInterface');
    $response = [
      "{$prefix}." . $this->randomMachineName(),
      "{$prefix}." . $this->randomMachineName(),
    ];
    $storage->expects($this->once())
      ->method('listAll')
      ->with($prefix)
      ->willReturn($response);
    $cache = new NullBackend(__FUNCTION__);
    $cachedStorage = new CachedStorage($storage, $cache);
    $this->assertEquals($response, $cachedStorage->listAll($prefix));
    $this->assertEquals($response, $cachedStorage->listAll($prefix));
  }

}