Spring cloud contract and webflux routing

Question

I'm trying to use spring cloud contract with a rest service using spring 5 routing but it doesn't work. I'm in the client side and i'm trying to use a stub runner within a junit test. If i use i classic @RestController and flux it works fine but if i try to change the controller using a RouterFunction it doesn't work and i obtain a 404. This is my sample code.

pom.xml

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
<dependencies>
...
   <dependency>
               <groupId>org.springframework.cloud</groupId>
               <artifactId>spring-cloud-starter-contract-stub-runner</artifactId>
               <scope>test</scope>
   </dependency>
</dependencies>

Routing.java

@Configuration
@EnableWebFlux
public class Routing {

    @Autowired
    private TestLoginController loginController;

    @Bean
    public HttpHandler routerFunction() {
        return WebHttpHandlerBuilder
                .webHandler(RouterFunctions.toWebHandler(createRouterFunction()))
                .build();
    }

    private RouterFunction<ServerResponse> createRouterFunction() {
        return route(POST("/testlogin"), loginController::testLogin);
    }
}

TestLoginController.java

@Component
public class TestLoginController {

    @Autowired
    private TestLoginService testLoginService;

    public Mono<ServerResponse> testLogin(ServerRequest request) {
        return Mono.just(request)
                   .flatMap(req -> ServerResponse.ok()
                                                 .body(testLoginService.testLogin(request.bodyToMono(LoginRequest.class)), LoginResponse.class)
                           );
    }
}

DemoApplicationTest.java

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@AutoConfigureStubRunner(ids = {"groupId:artifactId:+:stubs:8090"},
        stubsMode = StubRunnerProperties.StubsMode.LOCAL)
public class DemoApplicationTests {

    @LocalServerPort
    private int port;


    @Test
    public void contextLoads() throws Exception {
        LoginRequest request = new LoginRequest();

        WebTestClient
                .bindToServer()
                .baseUrl("http://localhost:" + port)
                .build()
                .post()
                .uri("testlogin").accept(MediaType.APPLICATION_JSON)
                .body(BodyInserters.fromObject(request))
                .exchange()
                .expectStatus().isOk()
                .expectBody()
                ....
    }

}

I have the same problem even if i remove the @AutoConfigureStubRunner annotation. If i only add the stub runner dependency i figure this behavior i find this problem. I also tried to use the latest versio of spring boot and spring cloud contract but i have the same issue. anyone can help me?

Answer 1

Spring Cloud Contract Stub Runner just starts a WireMock server on a given (or random port). Nothing related to WebTestClient takes place with Stub Runner. In other words, most likely you've misconfigured WebTestClient .

Let's try to ensure that you're not misusing the project. If you have service A calling service B via WebClient, then service B should have contracts defined, from which tests and spans would be created. Then on the service A side you will use Spring Cloud Contract Stub Runner to start the stubs of service B. Whatever you use (RestTemplate, WebClient, whatever) you will still send an HTTP call to a WireMock server that we start for you.

Example of how to use Spring Cloud Contract Stub Runner with WebTestClient (taken from: https://github.com/spring-cloud-samples/spring-cloud-contract-samples/blob/master/consumer/src/test/java/com/example/BeerControllerWebClientTest.java )

package com.example;
 import java.util.Objects;
 import org.junit.Test;
import org.junit.runner.RunWith;
 import org.springframework.boot.test.autoconfigure.json.AutoConfigureJsonTesters;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
import org.springframework.cloud.contract.stubrunner.spring.AutoConfigureStubRunner;
import org.springframework.cloud.contract.stubrunner.spring.StubRunnerPort;
import org.springframework.cloud.contract.stubrunner.spring.StubRunnerProperties;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.reactive.server.WebTestClient;
 /**
 * @author Marcin Grzejszczak
 */
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.MOCK)
@AutoConfigureMockMvc
@AutoConfigureJsonTesters
//remove::start[]
@AutoConfigureStubRunner(stubsMode = StubRunnerProperties.StubsMode.LOCAL, ids = "com.example:beer-api-producer-webflux")
//remove::end[]
@DirtiesContext
//@org.junit.Ignore
public class BeerControllerWebClientTest extends AbstractTest {
    //remove::start[]
    @StubRunnerPort("beer-api-producer-webflux") int producerPort;
    //remove::end[]
    @Test public void should_give_me_a_beer_when_im_old_enough() throws Exception {
        //remove::start[]
        WebTestClient.bindToServer()
                .build()
                .post()
                .uri("http://localhost:" + producerPort + "/check")
                .syncBody(new WebClientPerson("marcin", 22))
                .header("Content-Type", "application/json")
                .exchange()
                .expectStatus().is2xxSuccessful()
                .expectBody(WebClientResponse.class)
                .isEqualTo(new WebClientResponse(WebClientResponseStatus.OK));
        //remove::end[]
    }
    @Test public void should_reject_a_beer_when_im_too_young() throws Exception {
        //remove::start[]
        WebTestClient.bindToServer()
                .build()
                .post()
                .uri("http://localhost:" + producerPort + "/check")
                .syncBody(new WebClientPerson("marcin", 17))
                .header("Content-Type", "application/json")
                .exchange()
                .expectStatus().is2xxSuccessful()
                .expectBody(WebClientResponse.class)
                .isEqualTo(new WebClientResponse(WebClientResponseStatus.NOT_OK));
        //remove::end[]
    }
}
 class WebClientPerson {
    public String name;
    public int age;
    public WebClientPerson(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public WebClientPerson() {
    }
}
 class WebClientResponse {
    public WebClientResponseStatus status;
    WebClientResponse(WebClientResponseStatus status) {
        this.status = status;
    }
    WebClientResponse() {
    }
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        WebClientResponse that = (WebClientResponse) o;
        return status == that.status;
    }
    @Override
    public int hashCode() {
        return Objects.hash(status);
    }
}
 enum WebClientResponseStatus {
    OK, NOT_OK
}