On testing Spring Cloud Stream function, Spring Cloud Contract outputMessage channel bean is not a org.springframework.messaging.PollableChannel

Question

I'm trying to create a Spring Cloud Contract to test messages when using Spring Cloud Stream. I've included the dependencies in pom.xml

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-stream-binder-kafka</artifactId>
</dependency>
<!--TEST-->
<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-stream-test-support</artifactId>
        <scope>test</scope>
</dependency>
<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-contract-verifier</artifactId>
        <scope>test</scope>
</dependency>
<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-stream</artifactId>
        <type>test-jar</type>
        <scope>test</scope>
        <classifier>test-binder</classifier>
</dependency>

and configured the contracts plugin

 <!-- Contracts -->
 <plugin>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-contract-maven-plugin</artifactId>
        <version>${spring-cloud-contract.version}</version>
        <extensions>true</extensions>
        <configuration>
           <baseClassForTests>com.example.streams.kafkastreamer.KafkaStreamerApplicationTests
           </baseClassForTests>
        </configuration>
 </plugin>

Then I've ran a simple application locally in order to check that everything is working as expected. However, after creating a Spring Cloud Contract test following the documentation I'm getting the following error while running the generated test

org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'uppercase-out-0' is expected to be of type 'org.springframework.messaging.PollableChannel' but was actually of type 'org.springframework.cloud.stream.messaging.DirectWithAttributesChannel'

I've checked that the created test looks like the one at the documentation, and it kinda does it to me

@Test
public void validate_consume() throws Exception {
    // given:
        ContractVerifierMessage inputMessage = contractVerifierMessaging.create(
                "[\"MIAU\"]"
                    , headers()
                        .header("sample", "header")
        );

    // when:
        contractVerifierMessaging.send(inputMessage, "uppercase-in-0");

    // then:
        ContractVerifierMessage response = contractVerifierMessaging.receive("uppercase-out-0");
        assertThat(response).isNotNull();

    // and:
        assertThat(response.getHeader("contentType")).isNotNull();
        assertThat(response.getHeader("contentType").toString()).isEqualTo("application/json");

    // and:
        DocumentContext parsedJson = JsonPath.parse(contractVerifierObjectMapper.writeValueAsString(response.getPayload()));
        assertThatJson(parsedJson).field("['attributes']").field("['id']").isEqualTo("com.example.streams.kafkastreamer.KafkaStreamerApplication$$EnhancerBySpringCGLIB$$cf6cc14c2020-03-05T12:07:05.366");
        assertThatJson(parsedJson).field("['attributes']").field("['source']").isEqualTo("file:///com/example/streams/kafkastreamer");
        assertThatJson(parsedJson).field("['attributes']").field("['specversion']").isEqualTo("1.0");
        assertThatJson(parsedJson).field("['attributes']").field("['type']").isEqualTo("My.test.event.type");
        assertThatJson(parsedJson).field("['attributes']").field("['datacontenttype']").isEqualTo("application/json");
        assertThatJson(parsedJson).field("['attributes']").field("['dataschema']").isNull();
        assertThatJson(parsedJson).field("['attributes']").field("['subject']").isNull();
        assertThatJson(parsedJson).field("['attributes']").field("['time']").isNull();
        assertThatJson(parsedJson).field("['data']").field("['value']").isEqualTo("MIAU");
        assertThatJson(parsedJson).field("['dataBase64']").isNull();
        assertThatJson(parsedJson).field("['extensions']").field("['specversion']").isEqualTo("1.0");
        assertThatJson(parsedJson).array("['extensionsFormats']").isEmpty();
}

In the Spring Cloud Contract documentation sample, jms is being used and the channel is set as sentTo('jms:output'). Since I'm using a Spring Cloud Stream Binder I'm setting the name of the channel according to the definition o my binder as sentTo('uppercase-out-0'). Here is my application properties

#stubrunner.integration.enabled: false To make sure is using Spring Cloud Stream
spring.cloud.stream.bindings.uppercase-in-0.destination=test
spring.cloud.stream.bindings.uppercase-in-0.group=testGroup
spring.cloud.stream.bindings.uppercase-out-0.destination=hood
spring.cloud.stream.bindings.consume-in-0.destination=hood
spring.cloud.stream.bindings.consume-out-0.destination=downtown
spring.cloud.function.definition=uppercase;consume

My question is, why is the channel uppercase-out-0 not implementing a requiered PollableChannel? I guess I misunderstood something from the official documenation either from Spring Cloud Stream or from Spring Cloud Contract but cannot realise what.

Just a few more info. My guess is that autoconfiguration is configuring a bean of type SpringIntegrationSubMessages but should be StreamStubMessages. However, I don't know how or why this is happening. Am I guessing right?

Answer 1

The problem was comming from my parent test class configuration. At some point my IDE suggest me adding a component scan because was not finding a bean for

@Autowired
private MessageVerifier verifier;

so I added @ComponentScan(basePackages={"org.springframework.cloud.contract.verifier.messaging"}) and ended up initializing some beans that made conditional beans in ContractVerifierStreamAutoConfiguration not be configured, but SpringIntegrationSubMessages. Found that reviewing that in the official documentation no @ComponentScan was being include and I cleaned my code