--- /dev/null
+<?php
+
+namespace Drupal\Tests\rest\Functional\EntityResource\EntityTest;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+
+/**
+ * Test that internal properties are not exposed in the 'json' format.
+ *
+ * @group rest
+ */
+class EntityTestJsonInternalPropertyNormalizerTest extends EntityTestResourceTestBase {
+
+ use AnonResourceTestTrait;
+
+ /**
+ * {@inheritdoc}
+ */
+ protected static $format = 'json';
+
+ /**
+ * {@inheritdoc}
+ */
+ protected static $mimeType = 'application/json';
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getExpectedNormalizedEntity() {
+ $expected = parent::getExpectedNormalizedEntity();
+ // The 'internal_value' property in test field type is not exposed in the
+ // normalization because setInternal(FALSE) was not called for this
+ // property.
+ // @see \Drupal\entity_test\Plugin\Field\FieldType\InternalPropertyTestFieldItem::propertyDefinitions
+ $expected['field_test_internal'] = [
+ [
+ 'value' => 'This value shall not be internal!',
+ 'non_internal_value' => 'Computed! This value shall not be internal!',
+ ],
+ ];
+ return $expected;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function createEntity() {
+ if (!FieldStorageConfig::loadByName('entity_test', 'field_test_internal')) {
+ FieldStorageConfig::create([
+ 'entity_type' => 'entity_test',
+ 'field_name' => 'field_test_internal',
+ 'type' => 'internal_property_test',
+ 'cardinality' => 1,
+ 'translatable' => FALSE,
+ ])->save();
+ FieldConfig::create([
+ 'entity_type' => 'entity_test',
+ 'field_name' => 'field_test_internal',
+ 'bundle' => 'entity_test',
+ 'label' => 'Test field with internal and non-internal properties',
+ ])->save();
+ }
+
+ $entity = parent::createEntity();
+ $entity->field_test_internal = [
+ 'value' => 'This value shall not be internal!',
+ ];
+ $entity->save();
+ return $entity;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getNormalizedPostEntity() {
+ return parent::getNormalizedPostEntity() + [
+ 'field_test_internal' => [
+ [
+ 'value' => 'This value shall not be internal!',
+ ],
+ ],
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getExpectedCacheContexts() {
+ return Cache::mergeContexts(parent::getExpectedCacheContexts(), ['request_format']);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getExpectedCacheTags() {
+ return Cache::mergeTags(parent::getExpectedCacheTags(), ['you_are_it', 'no_tag_backs']);
+ }
+
+}