When upgrading my page from D8 to D9, I reached below php errors:
Error: Call to a member function getDatasourceId() on null in Drupal\facets\Plugin\facets\processor\ListItemProcessor->build() (line 108 of /var/www/html/www/modules/contrib/facets/src/Plugin/facets/processor/ListItemProcessor.php)
Error: Call to a member function getDatasource() on null in Drupal\facets\Plugin\facets\processor\ListItemProcessor->build() (line 111 of /var/www/html/www/modules/contrib/facets/src/Plugin/facets/processor/ListItemProcessor.php)
Error: Call to a member function getDataDefinition() on null in Drupal\facets\Plugin\facets\processor\ListItemProcessor->build() (line 131 of /var/www/html/www/modules/contrib/facets/src/Plugin/facets/processor/ListItemProcessor.php)
It seem this problem caused by lacking field data.
Needs work
2.0
Code
The change is currently missing an automated test that fails when run with the original code, and succeeds when the bug has been fixed.
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.