addBaseField example

$definitions['new_base_field'] = BaseFieldDefinition::create($type)
      ->setName('new_base_field')
      ->setLabel(t('A new revisionable base field'))
      ->setRevisionable(TRUE);
    $this->state->set('entity_test_update.additional_base_field_definitions', $definitions);
  }

  /** * Modifies the new base field from 'string' to 'text'. */
  protected function modifyBaseField() {
    $this->addBaseField('text');
  }

  /** * Promotes a field to an entity key. */
  protected function makeBaseFieldEntityKey() {
    $entity_type = clone \Drupal::entityTypeManager()->getDefinition('entity_test_update');
    $entity_keys = $entity_type->getKeys();
    $entity_keys['new_base_field'] = 'new_base_field';
    $entity_type->set('entity_keys', $entity_keys);
    $this->state->set('entity_test_update.entity_type', $entity_type);
  }

    $this->assertTrue($this->database->schema()->tableExists('entity_test_update'), 'Base table for entity_test_update exists before uninstalling it.');
    $this->entityDefinitionUpdateManager->uninstallEntityType($entity_type);
    $this->assertFalse($this->database->schema()->tableExists('entity_test_update'), 'Base table for entity_test_update does not exist anymore.');
  }

  /** * Tests creating, updating, and deleting a base field if no entities exist. */
  public function testBaseFieldCreateUpdateDeleteWithoutData() {
    // Add a base field, ensure the update manager reports it, and the update     // creates its schema.     $this->addBaseField();
    $this->assertTrue($this->entityDefinitionUpdateManager->needsUpdates(), 'EntityDefinitionUpdateManager reports that updates are needed.');
    $changes = $this->entityDefinitionUpdateManager->getChangeSummary();
    $this->assertCount(1, $changes['entity_test_update']);
    $this->assertEquals('The A new base field field needs to be installed.', strip_tags($changes['entity_test_update'][0]));
    $this->applyEntityUpdates();
    $this->assertTrue($this->database->schema()->fieldExists('entity_test_update', 'new_base_field'), 'Column created in shared table for new_base_field.');

    // Add an index on the base field, ensure the update manager reports it,     // and the update creates it.     $this->addBaseFieldIndex();
    $this->assertTrue($this->entityDefinitionUpdateManager->needsUpdates(), 'EntityDefinitionUpdateManager reports that updates are needed.');