--- /dev/null
+<?php
+
+namespace Drupal\Tests\field\Functional\Update;
+
+use Drupal\FunctionalTests\Update\UpdatePathTestBase;
+
+/**
+ * Tests the update for the entity reference 'handler' setting.
+ *
+ * @group field
+ */
+class EntityReferenceHandlerSettingUpdateTest extends UpdatePathTestBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setDatabaseDumpFiles() {
+ $this->databaseDumpFiles = [
+ __DIR__ . '/../../../../../system/tests/fixtures/update/drupal-8.bare.standard.php.gz',
+ ];
+ }
+
+ /**
+ * Tests field_post_update_entity_reference_handler_setting().
+ *
+ * @see field_post_update_entity_reference_handler_setting()
+ */
+ public function testFieldPostUpdateERHandlerSetting() {
+ $configFactory = $this->container->get('config.factory');
+
+ // Load the 'node.article.field_image' field config, and check that its
+ // 'handler' setting is wrong.
+ /** @var \Drupal\Core\Config\Config */
+ $config = $configFactory->get('field.field.node.article.field_image');
+ $settings = $config->get('settings');
+ $this->assertEqual($settings['handler'], 'default:node');
+
+ // Run updates.
+ $this->runUpdates();
+
+ // Reload the config, and check that the 'handler' setting has been fixed.
+ $config = $configFactory->get('field.field.node.article.field_image');
+ $settings = $config->get('settings');
+ $this->assertEqual($settings['handler'], 'default:file');
+ }
+
+}