Nested categories from Drupal 8

Running a migration with v 1.67.1 on Drupal 8.6.2, I found that all the categories were being flattened – no parent categories were migrated. Looking into it, the code doesn’t to accommodate Drupal 8.5+’s new taxonomy_term__parent table. I was able to fix it by adding another case to get_taxonomy_term_hierarchy():

$table_name = 'taxonomy_term__parent';
$sql = "
    SELECT h.entity_id as tid, h.parent_target_id as parent
    FROM ${prefix}${table_name} h
    WHERE h.parent_target_id != 0
";

Thanks for this well-written plugin. I hope this is helpful.