class CommentStatisticsUnitTest

class CommentStatisticsUnitTest extends UnitTestCase {
  
  /**
   * Mock statement.
   *
   * @var \Drupal\Core\Database\StatementInterface
   */
  protected $statement;
  
  /**
   * Mock select interface.
   *
   * @var \Drupal\Core\Database\Query\SelectInterface
   */
  protected $select;
  
  /**
   * Mock database connection.
   *
   * @var \Drupal\Core\Database\Connection
   */
  protected $database;
  
  /**
   * CommentStatistics service under test.
   *
   * @var \Drupal\comment\CommentStatisticsInterface
   */
  protected $commentStatistics;
  
  /**
   * Counts calls to fetchAssoc().
   *
   * @var int
   */
  protected $calls_to_fetch;
  
  /**
   * Sets up required mocks and the CommentStatistics service under test.
   */
  protected function setUp() : void {
    $this->statement = $this->getMockBuilder('Drupal\\sqlite\\Driver\\Database\\sqlite\\Statement')
      ->disableOriginalConstructor()
      ->getMock();
    $this->statement
      ->expects($this->any())
      ->method('fetchObject')
      ->willReturnCallback([
      $this,
      'fetchObjectCallback',
    ]);
    $this->select = $this->getMockBuilder('Drupal\\Core\\Database\\Query\\Select')
      ->disableOriginalConstructor()
      ->getMock();
    $this->select
      ->expects($this->any())
      ->method('fields')
      ->will($this->returnSelf());
    $this->select
      ->expects($this->any())
      ->method('condition')
      ->will($this->returnSelf());
    $this->select
      ->expects($this->any())
      ->method('execute')
      ->willReturn($this->statement);
    $this->database = $this->getMockBuilder('Drupal\\Core\\Database\\Connection')
      ->disableOriginalConstructor()
      ->getMock();
    $this->database
      ->expects($this->once())
      ->method('select')
      ->willReturn($this->select);
    $this->commentStatistics = new CommentStatistics($this->database, $this->createMock('Drupal\\Core\\Session\\AccountInterface'), $this->createMock(EntityTypeManagerInterface::class), $this->createMock('Drupal\\Core\\State\\StateInterface'), $this->database);
  }
  
  /**
   * Tests the read method.
   *
   * @see \Drupal\comment\CommentStatistics::read()
   *
   * @group Drupal
   * @group Comment
   */
  public function testRead() {
    $this->calls_to_fetch = 0;
    $results = $this->commentStatistics
      ->read([
      '1' => 'boo',
      '2' => 'foo',
    ], 'snafus');
    $this->assertEquals([
      'something',
      'something-else',
    ], $results);
  }
  
  /**
   * Return value callback for fetchObject() function on mocked object.
   *
   * @return bool|string
   *   'Something' on first, 'something-else' on second and FALSE for the
   *   other calls to function.
   */
  public function fetchObjectCallback() {
    $this->calls_to_fetch++;
    switch ($this->calls_to_fetch) {
      case 1:
        return 'something';
      case 2:
        return 'something-else';
      default:
        return FALSE;
    }
  }

}