Camel: How to mock a route with two endpoints

Question

I'm new to Camel and I need to understand how to unit test my route that has two endpoints. The first endpoints gets a user ID and uses that for the second endpoint.

public RouteBuilder routeBuilder() {
    return new RouteBuilder() {
        @Override
        public void configure() throws HttpOperationFailedException {
            this.from(MyServiceConstant.ROUTE)
                    .setHeader(...)
                    .setHeader(...)
                    .to(MyConstants.THE_FIRST_ROUTE)
                    .setHeader(...)
                    .setHeader(...)
                    .process(...)
                    .setProperty(...)
                    .to(MyConstants.THE_SECOND_ROUTE)
        }
    };
}

So I have to mock both the MyConstants.THE_FIRST_ROUTE and MyConstants.THE_SECOND_ROUTE in my Test class. I did that but am not sure how to write the test. All I'm doing is hitting the second endpoint but don't know how to trigger the first.

@Produce(uri = MyServiceConstant.ROUTE)
private MyService myService;

@EndpointInject(uri = "mock:" + MyConstants.THE_FIRST_ROUTE)
private MockEndpoint mockFirstService;

@EndpointInject(uri = ""mock:" + MyConstants.THE_SECOND_ROUTE)
private MockEndpoint mockSecondService;

@Test
@DirtiesContext
public void getDetails()throws Exception {

    // **The missing part**: Is this the right way to call my first service? 
    this.mockFirstService.setUserId("123456");

    // this returns a JSON that I'll compare the service response to
    this.mockSecondService.returnReplyBody(...PATH to JSON file);

    UserDetail userDetailsInfo = this.myService.getUserDetails(...args)

    // all of my assertions
    assertEquals("First name", userDetailsInfo.getFirstName());

    MockEndpoint.assertIsSatisfied();
}

Answer 1

I got some time today to quickly hack around some demo code, with Camel Spring boot archetype. Here we go. My route produces messages from a timer component. Explicit delivery to an endpoint is not used.

//Route Definition - myBean::saySomething() always returns String "Hello World"
@Component
public class MySpringBootRouter extends RouteBuilder {

    @Override
    public void configure() {
        from("timer:hello?period={{timer.period}}").routeId("hello_route")
            .transform().method("myBean", "saySomething")
            .to("log:foo")
                .setHeader("test_header",constant("test"))
            .to("log:bar");
    }

}

@RunWith(CamelSpringBootRunner.class)
@SpringBootTest
public class MySpringBootRouterTest {

    @Autowired
    SpringCamelContext defaultContext;

    @EndpointInject("mock:foo")
    private MockEndpoint mockFoo;
    @EndpointInject("mock:bar")
    private MockEndpoint mockBar;

    @Test
    @DirtiesContext
    public void getDetails() throws Exception {
        assertNotNull(defaultContext);
        mockBar.expectedHeaderReceived("test_header", "test");
        mockBar.expectedMinimumMessageCount(5);
        MockEndpoint.setAssertPeriod(defaultContext, 5_000L);
        MockEndpoint.assertIsSatisfied(mockFoo, mockBar);
        mockFoo.getExchanges().stream().forEach( exchange -> assertEquals(exchange.getIn().getBody(),"Hello World"));

        //This works too
        //mockBar.assertIsSatisfied();
        //mockFoo.assertIsSatisfied();
    }

    @Before
    public void attachTestProbes() throws Exception {
        //This is Camel 3.0 API with RouteReifier
        RouteReifier.adviceWith(defaultContext.getRouteDefinition("hello_route"), defaultContext, new AdviceWithRouteBuilder() {
            @Override
            public void configure() throws Exception {
           //Hook into the current route, intercept log endpoints and reroute them to mock
                interceptSendToEndpoint("log:foo").to("mock:foo");
                interceptSendToEndpoint("log:bar").to("mock:bar");
            }
        });
    }

}

Warning to visitors from future: The test case here demonstrates how to intercept log: endpoints with mock: and set expectations on them. The test case may not be testing anything worthwhile.

Answer 2

Here is a link to the Unit Test cases for the Mock component. It shows how to implement tests with mock: endpoints and CamelTestSupport. @Roman Vottner is completely right in his comment.

This test case may be of specific interest to you since it shows how to swap an smtp: endpoint with a mock: endpoint. Additionally, here is official documentation on how to mock existing endpoints (To use them like test probes).

Caveat: Please bear in mind that Camel 3.0 API is quite different from Camel 2.x API, in this region. Good luck!