class ToolkitTestBase

abstract class ToolkitTestBase extends WebTestBase {
  
  /**
   * Modules to enable.
   *
   * @var array
   */
  public static $modules = [
    'image_test',
  ];
  
  /**
   * The URI for the file.
   *
   * @var string
   */
  protected $file;
  
  /**
   * The image factory service.
   *
   * @var \Drupal\Core\Image\ImageFactory
   */
  protected $imageFactory;
  
  /**
   * The image object for the test file.
   *
   * @var \Drupal\Core\Image\ImageInterface
   */
  protected $image;
  protected function setUp() {
    parent::setUp();
    // Set the image factory service.
    $this->imageFactory = $this->container
      ->get('image.factory');
    // Pick a file for testing.
    $file = current($this->drupalGetTestFiles('image'));
    $this->file = $file->uri;
    // Setup a dummy image to work with.
    $this->image = $this->getImage();
    // Clear out any hook calls.
    $this->imageTestReset();
  }
  
  /**
   * Sets up an image with the custom toolkit.
   *
   * @return \Drupal\Core\Image\ImageInterface
   *   The image object.
   */
  protected function getImage() {
    $image = $this->imageFactory
      ->get($this->file, 'test');
    $this->assertTrue($image->isValid(), 'Image file was parsed.');
    return $image;
  }
  
  /**
   * Assert that all of the specified image toolkit operations were called
   * exactly once once, other values result in failure.
   *
   * @param $expected
   *   Array with string containing with the operation name, e.g. 'load',
   *   'save', 'crop', etc.
   */
  public function assertToolkitOperationsCalled(array $expected) {
    // If one of the image operations is expected, apply should be expected as
    // well.
    $operations = [
      'resize',
      'rotate',
      'crop',
      'desaturate',
      'create_new',
      'scale',
      'scale_and_crop',
      'my_operation',
      'convert',
    ];
    if (count(array_intersect($expected, $operations)) > 0 && !in_array('apply', $expected)) {
      $expected[] = 'apply';
    }
    // Determine which operations were called.
    $actual = array_keys(array_filter($this->imageTestGetAllCalls()));
    // Determine if there were any expected that were not called.
    $uncalled = array_diff($expected, $actual);
    if (count($uncalled)) {
      $this->assertTrue(FALSE, new FormattableMarkup('Expected operations %expected to be called but %uncalled was not called.', [
        '%expected' => implode(', ', $expected),
        '%uncalled' => implode(', ', $uncalled),
      ]));
    }
    else {
      $this->assertTrue(TRUE, new FormattableMarkup('All the expected operations were called: %expected', [
        '%expected' => implode(', ', $expected),
      ]));
    }
    // Determine if there were any unexpected calls.
    // If all unexpected calls are operations and apply was expected, we do not
    // count it as an error.
    $unexpected = array_diff($actual, $expected);
    if (count($unexpected) && (!in_array('apply', $expected) || count(array_intersect($unexpected, $operations)) !== count($unexpected))) {
      $this->assertTrue(FALSE, new FormattableMarkup('Unexpected operations were called: %unexpected.', [
        '%unexpected' => implode(', ', $unexpected),
      ]));
    }
    else {
      $this->assertTrue(TRUE, 'No unexpected operations were called.');
    }
  }
  
  /**
   * Resets/initializes the history of calls to the test toolkit functions.
   */
  public function imageTestReset() {
    // Keep track of calls to these operations
    $results = [
      'parseFile' => [],
      'save' => [],
      'settings' => [],
      'apply' => [],
      'resize' => [],
      'rotate' => [],
      'crop' => [],
      'desaturate' => [],
      'create_new' => [],
      'scale' => [],
      'scale_and_crop' => [],
      'convert' => [],
    ];
    \Drupal::state()->set('image_test.results', $results);
  }
  
  /**
   * Gets an array of calls to the test toolkit.
   *
   * @return array
   *   An array keyed by operation name ('parseFile', 'save', 'settings',
   *   'resize', 'rotate', 'crop', 'desaturate') with values being arrays of
   *   parameters passed to each call.
   */
  public function imageTestGetAllCalls() {
    return \Drupal::state()->get('image_test.results') ?: [];
  }

}