A Drupal 8 Migrate destination plugin that does nothing.

NoOp.php

<?php

namespace Drupal\migrate_nbr\Plugin\migrate\destination;

use Drupal\migrate\Plugin\MigrationInterface;
use Drupal\migrate\Plugin\migrate\destination\DestinationBase;
use Drupal\migrate\Row;

/**
 * Provides noop destination plugin.
 * 
 * Sometimes you want to use the migrate system for more, or less, that it was
 * designed for and this means not having anything to do in the destination
 * plugin.  e.g. your migration is too far in to back out and you need to 'fix'
 * something. A quick lightweight migration where the work happens in the
 * process section could do this.
 * 
 * This destination plugin is a 'quickfix' to the `null` destination plugin
 * always throwing false for `requirements_met`. I think this also sounds more
 * 'correct' in describing what the plugin does.
 *
 * @MigrateDestination(
 *   id = "noop"
 * )
 */
class NoOp extends DestinationBase {

  /**
   * {@inheritdoc}
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration) {
    parent::__construct($configuration, $plugin_id, $plugin_definition, $migration);
    $this->supportsRollback = FALSE;
  }

  /**
   * {@inheritdoc}
   */
  public function getIds() {
    return [];
  }

  /**
   * {@inheritdoc}
   */
  public function fields(MigrationInterface $migration = NULL) {
    return [];
  }

  /**
   * {@inheritdoc}
   */
  public function import(Row $row, array $old_destination_id_values = []) {
    // The no-op always succeeds. Returning TRUE here prevents a 'failed'
    // being thrown. However, it also gives no indication of progress.
    return TRUE;
  }

  /**
   * {@inheritdoc}
   */
  public function saveIdMapping(Row $row, array $destination_id_values, $source_row_status = MigrateIdMapInterface::STATUS_IMPORTED, $rollback_action = MigrateIdMapInterface::ROLLBACK_DELETE) {
    // Do nothing.
  }

}

Hello, thanks for plugin. I have one small issue - rollback is failed because mapping table is created without destid1 field. Is this intended?

vagrant@d8:/data/uniweb/uniweb-cms/cms3[3.x *]$ vendor/bin/drush @nz mr taxonomy_term_blog_categories_update

In Connection.php line 686:

  SQLSTATE[42S22]: Column not found: 1054 Unknown column 'destid1' in 'order clause': SELECT map.sourceid1 AS sourceid1, map.sourceid2 AS sourceid2
  FROM
  {migrate_map_taxonomy_term_blog_categories_update} map
  ORDER BY destid1 ASC; Array
  (
  )

In Statement.php line 59:

  SQLSTATE[42S22]: Column not found: 1054 Unknown column 'destid1' in 'order clause'

Hitting this a bit later, but finding the approach useful. To get past @havran's issue from https://gist.github.com/Unifex/d73a357992528a44f0f67ff4bdfcb3bc?permalink_comment_id=2755099#gistcomment-2755099, it's possible to specify an ID field:

  /**
   * {@inheritdoc}
   */
  public function getIds() {
    return [
      'noop' => [
        'type' => 'string',
      ],
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function fields(MigrationInterface $migration = NULL) {
    return [
      'noop' => $this->t('Nothing'),
    ];
  }

There should never be any value there, but it appears to satisfy whatever internals that are trying to make use of ID columns.

If already encountering the issue, it may be necessary to:

• drop the related migrate_map_ table for the no-op migration
• drush migrate:reset-status the target migration