mail_html_test.module

<?php


/**
 * @file
 * Helper module for the html mail and url conversion tests.
 */

/**
 * Implements hook_mail().
 */
function mail_html_test_mail($key, &$message, $params) {
    switch ($key) {
        case 'render_from_message_param':
            $message['body'][] = \Drupal::service('renderer')->renderPlain($params['message']);
            break;
    }
}