MyInvalidateTags::invalidateTags() contains the following code.
parent::invalidateTags($tags); // TODO: Change the autogenerated
$config = \Drupal::config('log_cache_tags.settings');
$purge_add = $config->get('log_cache_tags');
$output = '';
if ($purge_add != FALSE) {
// Log each time we send a record to the purge_queue_alt table.
$date = date('m/d/Y h:i:sa', \Drupal::time()->getCurrentTime());
$output .= $date . ' Cache Tags Invalidated: ' . implode(', ', $tags) . '. ';
\Drupal::logger('log_cache_tags')->notice($output);
}
return $output;
That is wrong: Any implementation of CacheTagsInvalidatorInterface::invalidateTags() do not return any value. See BackendChain::invalidateTags(), for example: It just invalidates the tags, without returning any value.
The line which initializes $output to an empty string and the line returning its value must be removed.
There are other changes to do to that code, but let's keep them for other issues.
This has been fixed in https://www.drupal.org/project/log_cache_tags/issues/3516353 📌 Fix some phpcs issues on testing Active