Hi everyone, how's it going? I'm trying to mock an external service that my API consumes. I found WireMock to be a good solution, but I'm facing some difficulties.

@Test
void shouldThrowExceptionWhenAuthorizationFails() throws Exception {
    Mockito.when(authorizationClient.execute())
            .thenReturn(new Authorize("fail", new Data(false)));

    var response = testScenario.executeTransferMoneyRequest(
            AMOUNT_125, 3, 38
    );

    assertThat(response.getStatus()).isEqualTo(403);

    Mockito.verify(authorizationClient, Mockito.times(1)).execute();
}

// I will use WireMock here.
public void paymentAllowedByAuthorizer(Boolean value) {
    if (Boolean.FALSE.equals(value)) {
        Mockito.when(authorizationClient.execute())
                .thenReturn(new Authorize("fail", new Data(value)));
    } else {
        Mockito.when(authorizationClient.execute())
                .thenReturn(new Authorize("success", new Data(value)));
    }
}

I'm running WireMock via

docker-compose

, along with my database.

services:
  wiremock:
    image: "wiremock/wiremock:latest"
    container_name: wiremock-standalone
    entrypoint: [ "/docker-entrypoint.sh", "--global-response-templating", "--disable-gzip", "--verbose" ]
    ports:
      - "8080:8080"

  postgres:
    image: postgres:15
    container_name: simplifypay_postgres
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: miguel
      POSTGRES_DB:
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data

volumes:
  postgres_data:
  wiremock_data:

I defined a Bean for WireMock in my test configuration class.

@TestConfiguration
public class TestConfig {
    @Bean
    public TransferMoneyTestScenario transferMoneyTestScenario() {
        return new TransferMoneyTestScenario();
    }

    @Bean
    public UserTestScenario userTestScenario() {
        return new UserTestScenario();
    }

    @Bean
    public WireMockServer wireMockServer() {
        return new WireMockServer(8080);
    }
}

My external server is a devtools instance, and it only returns two types of responses:

{
  "status": "success",
  "data": {
    "authorization": true
  }
}

OR

{
  "status": "fail",
  "data": {
    "authorization": false
  }
}

This is the class where I'll abstract the code to mock my external authorization server.

@SpringBootTest
public class MockingAuth {

    @Autowired
    private WireMockServer wireMockServer;

    @Autowired
    private JacksonTester<Authorize> jacksonTester;

    @BeforeEach
    void init() {
        WireMock.configureFor("localhost", 8080);
        WireMock.startRecording("<<https://util.devi.tools/api/v2/authorize>>");
    }

    @Test
    void recordingExternalRequests() throws IOException {
        var response = new Authorize("success", new Data(true));

        var json = jacksonTester.write(response).getJson();

        WireMock.stubFor(post(urlPathEqualTo("/api/v2/authorize"))
                .willReturn(aResponse()
                        .withStatus(200)
                        .withBody(json)));

        System.out.println("Make external service calls here to record.");
    }

    @AfterEach
    void tearDown() {
        var toReturn = WireMock.stopRecording().getStubMappings();
        System.out.println("Recording finished. Stubs generated: " + toReturn.size());

        wireMockServer.stop();
    }
}

However, I'm getting this error when running the test:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'SimplifyPay.infrastructure.controllers.ClasseDeTeste': Unsatisfied dependency expressed through field 'wireMockServer': No qualifying bean of type 'com.github.tomakehurst.wiremock.WireMockServer' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)

It is difficult to see what is going on here. The error says the problem is with

ClasseDeTeste

class. Is that class in the code you added to your question ?

@Lee Turner I wasn't expecting to get a reply so quickly, so I made some changes to try and solve the issue. I'll explain my API and code to make it clearer. Sorry if my initial question was confusing—it's my first time asking here. My API is a money transfer API, and it goes through several validations. One of these validations involves an external authorization system: https://util.devi.tools/api/v2/authorize. This is my implementation (I believe reading it isn't necessary to understand the issue):

@Service
@RequiredArgsConstructor(onConstructor= @__(@Autowired))
public class TransferMoneyImpl implements TransferMoneyUseCase {
    // ... (Logger, Repositories, etc.)
    
    private final AuthorizationClient authClient; 

    @Override
    @Transactional
    public TransferMoneyResponse execute(TransferMoneyRequest req) {
        // ... (Validations)

        authClient.execute(); // Calling the external authorization service
        <http://logger.info|logger.info>("External service authorized");

        // ... (Rest of the transfer logic)
    }

    // ... (Other methods)
}

The

AuthorizationClient

implementation is:

@FeignClient(
    value = "authorization-dev-tools",
    url="<<https://util.devi.tools/api/v2>>"
)
public interface AuthorizationClient {
    @GetMapping("/authorize")
    Authorize execute();
}

In my integration tests, I validate different use cases, and one of these tests checks how the API reacts when the external authorization denies the transfer. For this, I want to mock my

AuthorizationClient

, but I haven't succeeded in doing so yet. Currently, I'm trying to mock the

AuthorizationClient

using WireMock. I configured my

pom.xml

and

docker-compose

for this:

<!-- WireMock for mocking external APIs -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-contract-stub-runner</artifactId>
    <scope>test</scope>
</dependency>

services:
  wiremock:
    image: "wiremock/wiremock:latest"
    container_name: wiremock-standalone
    entrypoint: [ "/docker-entrypoint.sh", "--global-response-templating", "--disable-gzip", "--verbose" ]
    ports:
      - "8080:8080"

I added

WireMockServer

to my test configuration class as a Bean:

@TestConfiguration
public class TestConfig {
    @Bean
    public WireMockServer wireMockServer() {
        return new WireMockServer(8080);
    }
}

I created an abstraction for the

AuthorizationClient

test:

public class AuthorizationClientTest {

    @Autowired
    private static JacksonTester<Authorize> authorizeJacksonTester;

    public static void stubAuthorizationSuccess() throws Exception {
        var json = authorizeJacksonTester.write(new Authorize("success", new Data(true))).getJson();

        stubFor(get(urlEqualTo("/authorize"))
                .willReturn(aResponse()
                        .withStatus(200)
                        .withHeader("Content-Type", "application/json")
                        .withBody(json)));
    }

    public static void stubAuthorizationForbidden() throws Exception {
        var json = authorizeJacksonTester.write(new Authorize("fail", new Data(false))).getJson();

        stubFor(get(urlEqualTo("/authorize"))
                .willReturn(aResponse()
                        .withStatus(403)
                        .withHeader("Content-Type", "application/json")
                        .withBody(json)));
    }
}

And I implemented this abstraction in my test class:

@SpringBootTest()
@AutoConfigureWireMock(port = 8080)
public class MockingAuth {

    @Autowired
    private AuthorizationClient authorizationClient;

    @Test
    public void shouldReturnSuccessResponse() throws Exception {
        stubAuthorizationSuccess();

        Authorize response = authorizationClient.execute();
        assertThat(response.status()).isEqualTo("success");
        assertThat(response.data().authorization()).isTrue();
    }

    @Test
    public void shouldReturnForbiddenResponse() throws Exception {
        stubAuthorizationForbidden();

        Authorize response = authorizationClient.execute();
        assertThat(response.status()).isEqualTo("fail");
        assertThat(response.data().authorization()).isFalse();
    }
}

The

docker-compose

setup works perfectly, and I can access WireMock routes on

localhost:8080

. However, when I run my test, I get the following error with a massive stack trace, and I haven't been able to figure out the solution >: the stacktrace summary

java.lang.IllegalStateException: Failed to load ApplicationContext for [WebMergedContextConfiguration...]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.cloud.contract.wiremock.WireMockConfiguration': Invocation of init method failed
Caused by: com.github.tomakehurst.wiremock.common.FatalStartupException: java.lang.RuntimeException: java.io.IOException: Failed to bind to /0.0.0.0:8080
Caused by: java.lang.RuntimeException: java.io.IOException: Failed to bind to /0.0.0.0:8080
Caused by: java.io.IOException: Failed to bind to /0.0.0.0:8080
Caused by: java.net.BindException: Address already in use: bind

I don't use spring much so I am a little rusty here. Also, it is worth noting that I think

spring-cloud-starter-contract-stub-runner

uses a really old version of WireMock. We now have an official Spring integration that would probably be worth checking out given you are using the

3.x.x

release of Spring Boot. From looking at your error, WireMock is trying to connect to localhost:8080 but can't because something is already running on that port. Could it be that

spring-cloud-starter-contract-stub-runner

is trying to spin up a WireMock instance on localhost:8080 but you already have WireMock running in docker on that port ?

so let's try out, tks

Great stuff. Glad you got it all sorted.