Apache camel how to test a rollback scenario - apache-camel

Question

I have a generic message router that has its routes created at run time by various route builders based on some configuration.
The configuration is stored as XML and when loaded in memory it gets converted into a RouteConfig domain object exposing via its getters how the route should be build. Such a RouteConfig will have a getFromUri(), getDestinations(), getDeadLetterUri(), isTransacted(), etc methods defined.
An example such a route builder would look like below:
public class NonTransactedRouteBuilder extends AbstractRouteBuilder {
#Override
protected void buildRoute(String endPoint, RouteConfig routeConfig) {
RouteBean routeBean = getRouteBean(routeConfig.getBean());
final String[] destinations = routeConfig.getDestinations();
from(endPoint).routeId(createRouteId())
.autoStartup(false)
.threads(routeConfig.getThreads())
.filter(body().isNotNull())
.process((Processor) routeBean)
.filter(body().isNotNull())
.choice()
.when(header("dead.letter").isNotNull())
.to(getDeadLetterUri())
.otherwise()
.loadBalance().random()
.to(destinations)
.endChoice();
}
}
The above is just an example to give you an idea about what kind of routes we build. The only one relevant thing is that the route is not transacted. Now to unit test it works as expected we extend the TestNG flavor of CamelTestSupport and pass a mocked RouteConfig instance that will result in a route being configured to move messages between a direct:test and two mock:test1 and mock:test2 end points. The route bean has a bit of logic in it and depending of the message content help us with all testing scenarios:
#Test
public void shouldDiscardNullMessages() throws Exception {
...
}
#Test
public void shouldDiscardScamMessages() throws Exception {
...
}
#Test
public void shouldRouteMessageToDeadLetterQueue() throws Exception {
...
}
#Test(timeOut = 1000)
public void shouldRouteMessagesInALoadBalancedWay()
...
}
Everything works fine and we are very happy we can make code changes and test them immediately. However most of our routes builders will build transacted routes. From our integration and end to end tests we know the transacted functionality works fine but would be so much better to be able to test this at your code changing point with an unit test.
So my question is:
Having the same route as above with just an autoStartup(false).transacted() change on it would it be a way to getting the message back in the sender direct:test end point so we can cover this part of the functionality as well. We would be happy with any work around suggestion just to prove this aspect works.
Thank you in advance for your inputs.
UPDATE 1:
One of the things I tried was to configure my test camel context with a TransactionErrorHandler that had a mock jta transaction manager injected. Something like bleow:
#Test
public void shouldBeAbleToRollback() throws Exception {
TransactionErrorHandlerBuilder errorHandlerBuilder = new TransactionErrorHandlerBuilder();
errorHandlerBuilder.setTransactionManager(jtaTransactionManagerMock);
context().setErrorHandlerBuilder(errorHandlerBuilder);
template.sendBody(FROM_1, "rollback message");
...
}
Then I hoped that I will be able to capture a jtaTransactionManagerMock.rollback() but this did not happen. Wat would be the reason not to work.
UPDATE 2:
Unable to achieve the above I stepped back and started integrating ActiveMQ as a transactional resource in my unit tests and everything worked fine. In reality our routes include also file and database end points but for the purpose of unit testing a generic queue builder using just a JMS resource is enough. I did not realized how easy would be when you deal all day long with Webshere MQ manager where you need to have MQ manager created and configured and you have to have the queues already there and all the heavy infrastructure that you have to build for this. ActiveMQ just did a very good job.
However I will still be interested in whether there would be an way to mock this transnational behavior.