NullTestImageEffect.php

<?php

namespace Drupal\image_module_test\Plugin\ImageEffect;

use Drupal\Core\Image\ImageInterface;
use Drupal\image\ImageEffectBase;

/**
 * Performs no operation on an image resource.
 *
 * @ImageEffect(
 *   id = "image_module_test_null",
 *   label = @Translation("Image module test")
 * )
 */
class NullTestImageEffect extends ImageEffectBase {
    
    /**
     * {@inheritdoc}
     */
    public function transformDimensions(array &$dimensions, $uri) {
        // Unset image dimensions.
        $dimensions['width'] = $dimensions['height'] = NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function applyEffect(ImageInterface $image) {
        return TRUE;
    }

}