UserUid.php

<?php

namespace Drupal\comment\Plugin\views\filter;

use Drupal\Core\Database\Database;
use Drupal\views\Plugin\views\filter\FilterPluginBase;

/**
 * Filter handler, accepts user ID to check for nodes user posted/commented on.
 *
 * @ingroup views_filter_handlers
 *
 * @ViewsFilter("comment_user_uid")
 */
class UserUid extends FilterPluginBase {
    public function query() {
        $this->ensureMyTable();
        $subselect = Database::getConnection()->select('comment_field_data', 'c');
        $subselect->addField('c', 'cid');
        $subselect->condition('c.uid', $this->value, $this->operator);
        $entity_id = $this->definition['entity_id'];
        $entity_type = $this->definition['entity_type'];
        $subselect->where("[c].[entity_id] = [{$this->tableAlias}].[{$entity_id}]");
        $subselect->condition('c.entity_type', $entity_type);
        $condition = $this->view->query
            ->getConnection()
            ->condition('OR')
            ->condition("{$this->tableAlias}.uid", $this->value, $this->operator)
            ->exists($subselect);
        $this->query
            ->addWhere($this->options['group'], $condition);
    }

}