--- /dev/null
+<?php
+
+namespace Drupal\Tests\field_layout\Kernel;
+
+use Drupal\field_layout\Entity\FieldLayoutEntityViewDisplay;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * @coversDefaultClass \Drupal\field_layout\Entity\FieldLayoutEntityDisplayTrait
+ * @group field_layout
+ */
+class FieldLayoutEntityDisplayTest extends KernelTestBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ protected static $modules = ['layout_discovery', 'field_layout', 'entity_test', 'field_layout_test', 'system'];
+
+ /**
+ * @covers ::preSave
+ * @covers ::calculateDependencies
+ */
+ public function testPreSave() {
+ // Create an entity display with one hidden and one visible field.
+ $entity_display = FieldLayoutEntityViewDisplay::create([
+ 'targetEntityType' => 'entity_test',
+ 'bundle' => 'entity_test',
+ 'mode' => 'default',
+ 'status' => TRUE,
+ 'content' => [
+ 'foo' => ['type' => 'visible'],
+ 'bar' => ['type' => 'hidden'],
+ 'name' => ['type' => 'hidden', 'region' => 'content'],
+ ],
+ ]);
+
+ $expected = [
+ 'langcode' => 'en',
+ 'status' => TRUE,
+ 'dependencies' => [],
+ 'third_party_settings' => [
+ 'field_layout' => [
+ 'id' => 'layout_onecol',
+ 'settings' => [],
+ ],
+ ],
+ 'id' => 'entity_test.entity_test.default',
+ 'targetEntityType' => 'entity_test',
+ 'bundle' => 'entity_test',
+ 'mode' => 'default',
+ 'content' => [
+ 'foo' => [
+ 'type' => 'visible',
+ ],
+ 'bar' => [
+ 'type' => 'hidden',
+ ],
+ ],
+ 'hidden' => [],
+ ];
+ $this->assertEntityValues($expected, $entity_display->toArray());
+
+ // Save the display.
+ // the 'content' property and the visible field has the default region set.
+ $entity_display->save();
+
+ // The dependencies have been updated.
+ $expected['dependencies']['module'] = [
+ 'entity_test',
+ 'field_layout',
+ 'layout_discovery',
+ ];
+ // A third party setting is added by the entity_test module.
+ $expected['third_party_settings']['entity_test'] = ['foo' => 'bar'];
+ // The visible field is assigned the default region.
+ $expected['content']['foo']['region'] = 'content';
+ // The hidden field is removed from the list of visible fields, and marked
+ // as hidden.
+ unset($expected['content']['bar']);
+ $expected['hidden'] = ['bar' => TRUE];
+
+ $this->assertEntityValues($expected, $entity_display->toArray());
+
+ // Assign a new layout that has default settings and complex dependencies,
+ // but do not save yet.
+ $entity_display->setLayoutId('test_layout_main_and_footer');
+
+ // The default settings were added.
+ $expected['third_party_settings']['field_layout'] = [
+ 'id' => 'test_layout_main_and_footer',
+ 'settings' => [
+ 'setting_1' => 'Default',
+ ],
+ ];
+ // The field was moved to the default region.
+ $expected['content']['foo'] = [
+ 'type' => 'visible',
+ 'region' => 'main',
+ 'weight' => -4,
+ 'settings' => [],
+ 'third_party_settings' => [],
+ ];
+ $this->assertEntityValues($expected, $entity_display->toArray());
+
+ // After saving, the dependencies have been updated.
+ $entity_display->save();
+ $expected['dependencies']['module'] = [
+ 'dependency_from_annotation',
+ 'dependency_from_calculateDependencies',
+ 'entity_test',
+ 'field_layout',
+ 'field_layout_test',
+ ];
+ $this->assertEntityValues($expected, $entity_display->toArray());
+
+ // Assign a layout with provided settings.
+ $entity_display->setLayoutId('test_layout_main_and_footer', ['setting_1' => 'foobar']);
+ $entity_display->save();
+
+ // The setting overrides the default value.
+ $expected['third_party_settings']['field_layout']['settings']['setting_1'] = 'foobar';
+ $this->assertEntityValues($expected, $entity_display->toArray());
+
+ // Move a field to the non-default region.
+ $component = $entity_display->getComponent('foo');
+ $component['region'] = 'footer';
+ $entity_display->setComponent('foo', $component);
+ $entity_display->save();
+
+ // The field region is saved.
+ $expected['content']['foo']['region'] = 'footer';
+ $this->assertEntityValues($expected, $entity_display->toArray());
+
+ // Assign a different layout that shares the same non-default region.
+ $entity_display->setLayoutId('test_layout_content_and_footer');
+ $entity_display->save();
+
+ // The dependencies have been updated.
+ $expected['dependencies']['module'] = [
+ 'entity_test',
+ 'field_layout',
+ 'field_layout_test',
+ ];
+ // The layout has been updated.
+ $expected['third_party_settings']['field_layout'] = [
+ 'id' => 'test_layout_content_and_footer',
+ 'settings' => [],
+ ];
+ // The field remains in its current region instead of moving to the default.
+ $this->assertEntityValues($expected, $entity_display->toArray());
+
+ $this->container->get('module_installer')->uninstall(['field_layout']);
+
+ $entity_storage = $this->container->get('entity_type.manager')->getStorage('entity_view_display');
+ $entity_display = $entity_storage->load('entity_test.entity_test.default');
+
+ // The dependencies have been updated.
+ $expected['dependencies']['module'] = [
+ 'entity_test',
+ ];
+ // All field_layout settings were removed.
+ unset($expected['third_party_settings']['field_layout']);
+ // The field has returned to the default content region.
+ $expected['content']['foo']['region'] = 'content';
+ $this->assertEntityValues($expected, $entity_display->toArray());
+ }
+
+ /**
+ * Asserts than an entity has the correct values.
+ *
+ * @param mixed $expected
+ * @param array $values
+ * @param string $message
+ */
+ public static function assertEntityValues($expected, array $values, $message = '') {
+
+ static::assertArrayHasKey('uuid', $values);
+ unset($values['uuid']);
+
+ static::assertEquals($expected, $values, $message);
+ }
+
+}