--- /dev/null
+<?php
+
+namespace Drupal\Tests\image\Kernel;
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\image\Entity\ImageStyle;
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\node\Entity\NodeType;
+
+/**
+ * Tests the integration of ImageStyle with the core.
+ *
+ * @group image
+ */
+class ImageStyleIntegrationTest extends KernelTestBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public static $modules = ['image', 'file', 'field', 'system', 'user', 'node'];
+
+ /**
+ * Tests the dependency between ImageStyle and entity display components.
+ */
+ public function testEntityDisplayDependency() {
+ // Create two image styles.
+ /** @var \Drupal\image\ImageStyleInterface $style */
+ $style = ImageStyle::create(['name' => 'main_style']);
+ $style->save();
+ /** @var \Drupal\image\ImageStyleInterface $replacement */
+ $replacement = ImageStyle::create(['name' => 'replacement_style']);
+ $replacement->save();
+
+ // Create a node-type, named 'note'.
+ $node_type = NodeType::create(['type' => 'note']);
+ $node_type->save();
+
+ // Create an image field and attach it to the 'note' node-type.
+ FieldStorageConfig::create([
+ 'entity_type' => 'node',
+ 'field_name' => 'sticker',
+ 'type' => 'image',
+ ])->save();
+ FieldConfig::create([
+ 'entity_type' => 'node',
+ 'field_name' => 'sticker',
+ 'bundle' => 'note',
+ ])->save();
+
+ // Create the default entity view display and set the 'sticker' field to use
+ // the 'main_style' images style in formatter.
+ /** @var \Drupal\Core\Entity\Display\EntityViewDisplayInterface $view_display */
+ $view_display = EntityViewDisplay::create([
+ 'targetEntityType' => 'node',
+ 'bundle' => 'note',
+ 'mode' => 'default',
+ 'status' => TRUE,
+ ])->setComponent('sticker', ['settings' => ['image_style' => 'main_style']]);
+ $view_display->save();
+
+ // Create the default entity form display and set the 'sticker' field to use
+ // the 'main_style' images style in the widget.
+ /** @var \Drupal\Core\Entity\Display\EntityFormDisplayInterface $form_display */
+ $form_display = EntityFormDisplay::create([
+ 'targetEntityType' => 'node',
+ 'bundle' => 'note',
+ 'mode' => 'default',
+ 'status' => TRUE,
+ ])->setComponent('sticker', ['settings' => ['preview_image_style' => 'main_style']]);
+ $form_display->save();
+
+ // Check that the entity displays exists before dependency removal.
+ $this->assertNotNull(EntityViewDisplay::load($view_display->id()));
+ $this->assertNotNull(EntityFormDisplay::load($form_display->id()));
+
+ // Delete the 'main_style' image style. Before that, emulate the UI process
+ // of selecting a replacement style by setting the replacement image style
+ // ID in the image style storage.
+ /** @var \Drupal\image\ImageStyleStorageInterface $storage */
+ $storage = $this->container->get('entity.manager')->getStorage($style->getEntityTypeId());
+ $storage->setReplacementId('main_style', 'replacement_style');
+ $style->delete();
+
+ // Check that the entity displays exists after dependency removal.
+ $this->assertNotNull($view_display = EntityViewDisplay::load($view_display->id()));
+ $this->assertNotNull($form_display = EntityFormDisplay::load($form_display->id()));
+ // Check that the 'sticker' formatter component exists in both displays.
+ $this->assertNotNull($formatter = $view_display->getComponent('sticker'));
+ $this->assertNotNull($widget = $form_display->getComponent('sticker'));
+ // Check that both displays are using now 'replacement_style' for images.
+ $this->assertSame('replacement_style', $formatter['settings']['image_style']);
+ $this->assertSame('replacement_style', $widget['settings']['preview_image_style']);
+
+ // Delete the 'replacement_style' without setting a replacement image style.
+ $replacement->delete();
+
+ // The entity view and form displays exists after dependency removal.
+ $this->assertNotNull($view_display = EntityViewDisplay::load($view_display->id()));
+ $this->assertNotNull($form_display = EntityFormDisplay::load($form_display->id()));
+ // The 'sticker' formatter component should be hidden in view display.
+ $this->assertNull($view_display->getComponent('sticker'));
+ $this->assertTrue($view_display->get('hidden')['sticker']);
+ // The 'sticker' widget component should be active in form displays, but the
+ // image preview should be disabled.
+ $this->assertNotNull($widget = $form_display->getComponent('sticker'));
+ $this->assertSame('', $widget['settings']['preview_image_style']);
+ }
+
+}