Issue #2705531 by Jo Fitzgerald: View mode migration rollback fails

core/modules/field/tests/src/Kernel/Migrate/d7/RollbackViewModesTest.php

+<?php
+
+namespace Drupal\Tests\field\Kernel\Migrate\d7;
+
+use Drupal\Core\Entity\Entity\EntityViewMode;
+use Drupal\migrate\MigrateExecutable;
+
+/**
+ * Migrates and rolls back Drupal 7 view modes.
+ *
+ * @group field
+ */
+class RollbackViewModesTest extends MigrateViewModesTest {
+
+  /**
+   * Tests migrating D7 view modes, then rolling back.
+   */
+  public function testMigration() {
+    // Test that the view modes have migrated (prior to rollback).
+    parent::testMigration();
+
+    $this->executeRollback('d7_view_modes');
+
+    // Check that view modes have been rolled back.
+    $view_mode_ids = [
+      'comment.full',
+      'node.teaser',
+      'node.full',
+      'user.full',
+    ];
+    foreach ($view_mode_ids as $view_mode_id) {
+      $this->assertNull(EntityViewMode::load($view_mode_id));
+    }
+  }
+
+  /**
+   * Executes a single rollback.
+   *
+   * @param string|\Drupal\migrate\Plugin\MigrationInterface $migration
+   *   The migration to rollback, or its ID.
+   */
+  protected function executeRollback($migration) {
+    if (is_string($migration)) {
+      $this->migration = $this->getMigration($migration);
+    }
+    else {
+      $this->migration = $migration;
+    }
+    (new MigrateExecutable($this->migration, $this))->rollback();
+  }
+
+}

core/modules/migrate/src/Plugin/migrate/destination/EntityViewMode.php

@@ -20,4 +20,12 @@ public function getIds() {
     return $ids;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function rollback(array $destination_identifier) {
+    $destination_identifier = implode('.', $destination_identifier);
+    parent::rollback(array($destination_identifier));
+  }
+
 }