gistfile1.txt

  protected function assertIterator($entity_type) {
    $entity = $this->createTestEntity($entity_type);

    foreach ($entity as $name => $field) {
      $this->assertTrue($field instanceof FieldInterface, $entity_type . ": Field $name implements interface.");

      foreach ($field as $delta => $item) {
        $this->assertTrue($field[0] instanceof FieldItemInterface, $entity_type . ": Item $delta of field $name implements interface.");

        foreach ($item as $value_name => $value_property) {
          $this->assertTrue($value_property instanceof TypedDataInterface, $entity_type . ": Value $value_name of item $delta of field $name implements interface.");

          $value = $value_property->getValue();
          $this->assertTrue(!isset($value) || is_scalar($value) || $value instanceof EntityInterface, $entity_type . ": Value $value_name of item $delta of field $name is a primitive or an entity.");
        }
      }
    }

    $properties = $entity->getProperties();
    $this->assertEqual(array_keys($properties), array_keys($entity->getPropertyDefinitions()), format_string('%entity_type: All properties returned.', array('%entity_type' => $entity_type)));
    $this->assertEqual($properties, iterator_to_array($entity->getIterator()), format_string('%entity_type: Entity iterator iterates over all properties.', array('%entity_type' => $entity_type)));
  }