class NodeFieldOverridesTest

class NodeFieldOverridesTest extends EntityKernelTestBase {
    
    /**
     * Current logged in user.
     *
     * @var \Drupal\user\UserInterface
     */
    protected $user;
    
    /**
     * Modules to enable.
     *
     * @var array
     */
    public static $modules = [
        'user',
        'system',
        'field',
        'node',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() {
        parent::setUp();
        $this->installConfig([
            'user',
        ]);
        $this->user = $this->createUser();
        \Drupal::service('current_user')->setAccount($this->user);
    }
    
    /**
     * Tests that field overrides work as expected.
     */
    public function testFieldOverrides() {
        if (!NodeType::load('ponies')) {
            NodeType::create([
                'name' => 'Ponies',
                'type' => 'ponies',
            ])->save();
        }
        $override = BaseFieldOverride::loadByName('node', 'ponies', 'uid');
        if ($override) {
            $override->delete();
        }
        $uid_field = \Drupal::service('entity_field.manager')->getBaseFieldDefinitions('node')['uid'];
        $config = $uid_field->getConfig('ponies');
        $config->save();
        $this->assertEquals($config->get('default_value_callback'), 'Drupal\\node\\Entity\\Node::getDefaultEntityOwner');
        
        /** @var \Drupal\node\NodeInterface $node */
        $node = Node::create([
            'type' => 'ponies',
        ]);
        $owner = $node->getOwner();
        $this->assertInstanceOf(UserInterface::class, $owner);
        $this->assertEqual($owner->id(), $this->user
            ->id());
    }

}