class FieldKernelTestBase

abstract class FieldKernelTestBase extends KernelTestBase {
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'user',
    'system',
    'field',
    'text',
    'entity_test',
    'field_test',
  ];
  
  /**
   * Bag of created field storages and fields.
   *
   * Allows easy access to test field storage/field names/IDs/objects via:
   * - $this->fieldTestData->field_name[suffix]
   * - $this->fieldTestData->field_storage[suffix]
   * - $this->fieldTestData->field_storage_uuid[suffix]
   * - $this->fieldTestData->field[suffix]
   * - $this->fieldTestData->field_definition[suffix]
   *
   * @var \ArrayObject
   *
   * @see \Drupal\field\Tests\FieldUnitTestBase::createFieldWithStorage()
   */
  protected $fieldTestData;
  
  /**
   * @var string
   */
  protected string $entityId;
  
  /**
   * Set the default field storage backend for fields created during tests.
   */
  protected function setUp() : void {
    parent::setUp();
    $this->fieldTestData = new \ArrayObject([], \ArrayObject::ARRAY_AS_PROPS);
    $this->installEntitySchema('entity_test');
    $this->installEntitySchema('user');
    // Set default storage backend and configure the theme system.
    $this->installConfig([
      'field',
      'system',
      'user',
    ]);
    // Create user 1.
    $storage = \Drupal::entityTypeManager()->getStorage('user');
    $storage->create([
      'uid' => 1,
      'name' => 'entity-test',
      'mail' => 'entity@localhost',
      'status' => TRUE,
    ])
      ->save();
  }
  
  /**
   * Create a field and an associated field storage.
   *
   * @param string $suffix
   *   (optional) A string that should only contain characters that are valid in
   *   PHP variable names as well.
   * @param string $entity_type
   *   (optional) The entity type on which the field should be created.
   *   Defaults to "entity_test".
   * @param string $bundle
   *   (optional) The entity type on which the field should be created.
   *   Defaults to the default bundle of the entity type.
   */
  protected function createFieldWithStorage($suffix = '', $entity_type = 'entity_test', $bundle = NULL) {
    if (empty($bundle)) {
      $bundle = $entity_type;
    }
    $field_name = 'field_name' . $suffix;
    $field_storage = 'field_storage' . $suffix;
    $field_storage_uuid = 'field_storage_uuid' . $suffix;
    $field = 'field' . $suffix;
    $field_definition = 'field_definition' . $suffix;
    $this->fieldTestData->{$field_name} = $this->randomMachineName() . '_field_name' . $suffix;
    $this->fieldTestData->{$field_storage} = FieldStorageConfig::create([
      'field_name' => $this->fieldTestData->{$field_name},
      'entity_type' => $entity_type,
      'type' => 'test_field',
      'cardinality' => 4,
    ]);
    $this->fieldTestData->{$field_storage}
      ->save();
    $this->fieldTestData->{$field_storage_uuid} = $this->fieldTestData->{$field_storage}
      ->uuid();
    $this->fieldTestData->{$field_definition} = [
      'field_storage' => $this->fieldTestData->{$field_storage},
      'bundle' => $bundle,
      'label' => $this->randomMachineName() . '_label',
      'description' => $this->randomMachineName() . '_description',
      'settings' => [
        'test_field_setting' => $this->randomMachineName(),
      ],
    ];
    $this->fieldTestData->{$field} = FieldConfig::create($this->fieldTestData->{$field_definition});
    $this->fieldTestData->{$field}
      ->save();
    \Drupal::service('entity_display.repository')->getFormDisplay($entity_type, $bundle)
      ->setComponent($this->fieldTestData->{$field_name}, [
      'type' => 'test_field_widget',
      'settings' => [
        'test_widget_setting' => $this->randomMachineName(),
      ],
    ])
      ->save();
  }
  
  /**
   * Saves and reloads an entity.
   *
   * @param \Drupal\Core\Entity\EntityInterface $entity
   *   The entity to save.
   *
   * @return \Drupal\Core\Entity\EntityInterface
   *   The entity, freshly reloaded from storage.
   */
  protected function entitySaveReload(EntityInterface $entity) : EntityInterface {
    $entity->save();
    $controller = $this->container
      ->get('entity_type.manager')
      ->getStorage($entity->getEntityTypeId());
    $controller->resetCache();
    return $controller->load($entity->id());
  }
  
  /**
   * Validate and save entity. Fail if violations are found.
   *
   * @param \Drupal\Core\Entity\EntityInterface $entity
   *   The entity to save.
   */
  protected function entityValidateAndSave(EntityInterface $entity) {
    $violations = $entity->validate();
    if ($violations->count()) {
      $this->fail((string) $violations);
    }
    else {
      $entity->save();
    }
  }
  
  /**
   * Generate random values for a field_test field.
   *
   * @param int $cardinality
   *   Number of values to generate.
   *
   * @return array
   *   An array of random values, in the format expected for field values.
   */
  protected function _generateTestFieldValues($cardinality) {
    $values = [];
    for ($i = 0; $i < $cardinality; $i++) {
      // field_test fields treat 0 as 'empty value'.
      $values[$i]['value'] = mt_rand(1, 127);
    }
    return $values;
  }
  
  /**
   * Assert that a field has the expected values in an entity.
   *
   * This function only checks a single column in the field values.
   *
   * @param \Drupal\Core\Entity\EntityInterface $entity
   *   The entity to test.
   * @param string $field_name
   *   The name of the field to test.
   * @param array $expected_values
   *   The array of expected values.
   * @param string $langcode
   *   (Optional) The language code for the values. Defaults to
   *   \Drupal\Core\Language\LanguageInterface::LANGCODE_NOT_SPECIFIED.
   * @param string $column
   *   (Optional) The name of the column to check. Defaults to 'value'.
   */
  protected function assertFieldValues(EntityInterface $entity, $field_name, $expected_values, $langcode = LanguageInterface::LANGCODE_NOT_SPECIFIED, $column = 'value') {
    $expected_values_count = count($expected_values);
    // Re-load the entity to make sure we have the latest changes.
    $storage = $this->container
      ->get('entity_type.manager')
      ->getStorage($entity->getEntityTypeId());
    $storage->resetCache([
      $entity->id(),
    ]);
    $e = $storage->load($this->entityId);
    $field = $values = $e->getTranslation($langcode)->{$field_name};
    // Filter out empty values so that they don't mess with the assertions.
    $field->filterEmptyItems();
    $values = $field->getValue();
    $this->assertCount($expected_values_count, $values, 'Expected number of values were saved.');
    foreach ($expected_values as $key => $value) {
      $this->assertEquals($value, $values[$key][$column], "Value {$value} was saved correctly.");
    }
  }

}