--- /dev/null
+<?php
+
+namespace Drupal\Tests\image\Functional\Rest;
+
+use Drupal\image\Entity\ImageStyle;
+use Drupal\Tests\rest\Functional\EntityResource\EntityResourceTestBase;
+
+/**
+ * ResourceTestBase for ImageStyle entity.
+ */
+abstract class ImageStyleResourceTestBase extends EntityResourceTestBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public static $modules = ['image'];
+
+ /**
+ * {@inheritdoc}
+ */
+ protected static $entityTypeId = 'image_style';
+
+ /**
+ * The ImageStyle entity.
+ *
+ * @var \Drupal\image\ImageStyleInterface
+ */
+ protected $entity;
+
+ /**
+ * The effect UUID.
+ *
+ * @var string
+ */
+ protected $effectUuid;
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setUpAuthorization($method) {
+ $this->grantPermissionsToTestedRole(['administer image styles']);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function createEntity() {
+ // Create a "Camelids" image style.
+ $camelids = ImageStyle::create([
+ 'name' => 'camelids',
+ 'label' => 'Camelids',
+ ]);
+
+ // Add an image effect.
+ $effect = [
+ 'id' => 'image_scale_and_crop',
+ 'data' => [
+ 'anchor' => 'center-center',
+ 'width' => 120,
+ 'height' => 121,
+ ],
+ 'weight' => 0,
+ ];
+ $this->effectUuid = $camelids->addImageEffect($effect);
+
+ $camelids->save();
+
+ return $camelids;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getExpectedNormalizedEntity() {
+ return [
+ 'dependencies' => [],
+ 'effects' => [
+ $this->effectUuid => [
+ 'uuid' => $this->effectUuid,
+ 'id' => 'image_scale_and_crop',
+ 'weight' => 0,
+ 'data' => [
+ 'anchor' => 'center-center',
+ 'width' => 120,
+ 'height' => 121,
+ ],
+ ],
+ ],
+ 'label' => 'Camelids',
+ 'langcode' => 'en',
+ 'name' => 'camelids',
+ 'status' => TRUE,
+ 'uuid' => $this->entity->uuid(),
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getNormalizedPostEntity() {
+ // @todo Update in https://www.drupal.org/node/2300677.
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getExpectedUnauthorizedAccessMessage($method) {
+ if ($this->config('rest.settings')->get('bc_entity_resource_permissions')) {
+ return parent::getExpectedUnauthorizedAccessMessage($method);
+ }
+
+ return "The 'administer image styles' permission is required.";
+ }
+
+}