ClassNotFoundException with AWS messaging

Type: Bug

Component: SQS

Describe the bug When using spring-cloud-aws-messaging, without Webflux module and with embedded web server (as defined with WebEnvironment enum), tests fail with java.lang.ClassNotFoundException.

This happens, or at least I believe so, because WebTestClientContextCustomizer registers a WebTestClient in:

@Override
    public void customizeContext(ConfigurableApplicationContext context, MergedContextConfiguration mergedConfig) {
        SpringBootTest springBootTest = TestContextAnnotationUtils.findMergedAnnotation(mergedConfig.getTestClass(),
                SpringBootTest.class);
        if (springBootTest.webEnvironment().isEmbedded()) {
            registerWebTestClient(context);
        }
    }

This later on causes AbstractMethodMessageHandler.detectHandlerMethods to fail because WebTestClient methods are reflectively read and some of its methods contain undefined classes (like org.springframework.web.reactive.function.server.RouterFunction).

Versions are provided in gradle config, in sample.

Sample A simple gradle config:

plugins {
    id "org.springframework.boot" version "2.4.0"
    id "io.spring.dependency-management" version "1.0.10.RELEASE"
    id 'java'
}

group 'org.example'
version '1.0-SNAPSHOT'
sourceCompatibility = "11"
targetCompatibility = JavaVersion.VERSION_11

repositories {
    mavenCentral()
}

dependencies {
    implementation "org.springframework.boot:spring-boot-starter-web"
    implementation "org.springframework.cloud:spring-cloud-starter-aws-messaging:2.2.5.RELEASE"
    testImplementation("org.springframework.boot:spring-boot-starter-test")
}

tasks.withType(Test) {
    useJUnitPlatform()
}

Main class:

@SpringBootApplication
public class App {

    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}

Test class:

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
class AppTest {
    // Will fail to load ApplicationContext
    @Test
    void test() {
    }
}

spring-attic / spring-cloud-aws

ClassNotFoundException with AWS messaging #722