Apache Camel MockEndpoint mock the output

Question

Let's say I have an apache camel route like this:

from("direct:start")
    .routeId("aRouteId")
    .bean(someBusinnessTransformationBean).id("transformationBean")
    .bean(aPersistenceBean).id("persistenceBean")
    .to("direct:target");

And then, on my unit tests, I'm doing something like:

public class RouteTest extends CamelTestSupport {
    @Override
    public boolean isDumpRouteCoverage() { return true }

    @Override
    public boolean isUsedAdviceWith() { return true }

    @EndpointInject(uri = "mock:mockTransformationBean")
    protected MockEndpoint mockTransformationBean;

    @EndpointInject(uri = "mock:mockPersistenceBean")
    protected MockEndpoint mockPersistenceBean;

    @Test
    public void testRoute() throws Exception {
        context.getRouteDefinition("aRouteId").adviceWith(context, new AdviceWithRouteBuilder() {
            @Override
            public void configure() throws Exception {
                weaveById("transformationBean")
                    .replace()
                    .multicast()
                    .to(mockTransformationBean);

                weaveById("persistenceBean")
                    .replace()
                    .multicast()
                    .to(mockPersistenceBean);
            }
        });

        context.start();

        // Asserts the expectedMessageCount

        // Send a message with template.sendBody...

        assertMockEndpointSatisfied();
    }
}

Question:

How could I unit test this route properly, instead of just ensure the messageCount and received body (on the first bean).

Like, how could I mock the response of a MockEndpoint as I could do when using Mockito for unit testing:

when(mockTransformationBean.someHandler(...)).thenReturn(anExpectedObjectForMyUnitTestPropose);

Cheers, Nikolas

Why don't you just run the unit test and then compare the exchange body against some expected body? — Souciance Eqdam Rashti
Because I couldn't find a way to intercept the exchange body of the bean with the apache camel MockEndpoint. What I can is ensure the received body to the mock, but then, I want to ensure the first bean transform the body and send a different one to the second bean. — E. Nikolas de Oliveira
You can do an adviceWith and after the bean intercept and send it to a mockendpoint. Then assert what the message should be. — Souciance Eqdam Rashti

E. Nikolas de Oliveira E. Nikolas de Oliveira · Accepted Answer · 2016-11-22T20:42:53

After some research, documentation reading and so on, I come up with an acceptable solution for this:

weaveById("transformationBean")
    .replace()
    .to(mockTransformationBean)
    .setBody(constant(<myExpectedMockResponse>));

So later on, I can just do an assert like:

mockPersistenceBean.expectedBodiesReceivedInAnyOrder(
    <myExpectedMockResponse>
);

This way, it is possible to ensure not just if the beans and endpoints are receiving the proper body / header, but if any transformation in between the route is being done properly as well.

So it is possible to test the input and output of the code from a unit point of view, instead integrating it with a lot of other components unnecessary in an unit test.

Apache Camel MockEndpoint mock the output

2 Answers