[CAUSEWAY-2066] Invoking an action that returns null results in an NPE ... eg HelloWorldObject#delete().

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0-M2
• Assignee: Daniel Keir Haywood
• Reporter: Daniel Keir Haywood
• Created: 04/Jan/19 08:26
• Updated: 06/Jan/19 07:52
• Resolved: 04/Jan/19 08:36

Description

this stackt trace:

Stack trace:
java.lang.NullPointerException
java.util.Objects#requireNonNull(Objects.java:203)
java.util.Optional#<init>(Optional.java:96)
java.util.Optional#of(Optional.java:108)
java.util.stream.FindOps$FindSink$OfRef#get(FindOps.java:193)
java.util.stream.FindOps$FindSink$OfRef#get(FindOps.java:190)
java.util.stream.FindOps$FindOp#evaluateSequential(FindOps.java:152)
java.util.stream.AbstractPipeline#evaluate(AbstractPipeline.java:234)
java.util.stream.ReferencePipeline#findFirst(ReferencePipeline.java:464)
org.apache.isis.viewer.wicket.model.models.ActionModel#executeAction(ActionModel.java:474)

 

which results from this code:

return routingServices
    .filter(routingService->routingService.canRoute(result))        
    .map(routingService->{
        final Object routeTo = routingService.route(result);
        return routeTo != null? getPersistenceSession().adapterFor(routeTo): null;
    })
    .findFirst()
    .orElse(resultAdapter);

 

This isn't quite equivalent to the code in 1.16.x:

final Object result = resultAdapter != null ? resultAdapter.getObject() : null;
for (RoutingService routingService : routingServices) {
    final boolean canRoute = routingService.canRoute(result);
    if(canRoute) {
        final Object routeTo = routingService.route(result);
        return routeTo != null? getPersistenceSession().adapterFor(routeTo): null;
    }
}

return resultAdapter;