edlp_d8/sites/all/modules/contrib/search/search_api/tests/search_api_test_views/search_api_test_views.module

<?php

/**
 * @file
 * Contains hook implementations for the Search API Views Test module.
 */

use Drupal\search_api\Query\QueryInterface;

/**
 * Implements hook_search_api_query_alter().
 *
 * Prints the contents of the "search_api_retrieved_properties" query option to
 * the page (if present) so it can be checked by the testing code.
 */
function search_api_test_views_search_api_query_alter(QueryInterface $query) {
  $properties = $query->getOption('search_api_retrieved_properties');
  if ($properties) {
    $message = [];
    foreach ($properties as $datasource_properties) {
      foreach ($datasource_properties as $combined_property_path) {
        $message[] = "'$combined_property_path'";
      }
    }
    drupal_set_message(implode(' ', $message));
  }
}