When you pick a component and leave some props unmapped (no field, no static value), the row plugin still sends them to the component as empty strings. Most of the time that's OK, but if the component declares a class-typed prop such as: ``` attributes: type: Drupal\Core\Template\Attribute ``` and prop validation is active (it turns on automatically when justinrainbow/json-schema is around, e.g. with drupal/core-dev installed), there can be errors: ``` InvalidComponentException: Data provided to prop "attributes" ... is not a valid instance of "Drupal\Core\Template\Attribute" ``` Same goes for enums ('' is never in the enum prop definition) and blank strings also override any defaults the component declares. To reproduce: Create a page view, add a component with an attributes prop, enable the SDC row plugin, then leave attributes unmapped and visit the page. Instead of sending '', we could skip unmapped props instead of. If the prop isn't in the array, SDC fills in the component defaults and builds the Attribute object itself. MR coming up