Spring Boot Integration test throwing error and not able to pick up an existing bean in another maven module

Question

I have the following maven-based project structure

product-app
    product-web
    product-service
    product-integration-tests

There is an MailClientService service written in product-service module that I would like to do an integration test on. The integration test is obviously written in product-integration-tests module.

The product-web module has been already added as a dependency in the pom of product-integration-tests module.

However the problem is that during runtime of the integration test it is not able to construct the MailClientService bean and is throwing a runtime exception.

Exception

13:53:01.161 [main] ERROR org.springframework.test.context.TestContextManager - Caught exception while allowing TestExecutionListener [org.springframework.boot.test.autoconfigure.AutoConfigureReportTestExecutionListener@20b2475a] to prepare test instance [com.radial.hostedpayments.service.MailClientServiceIntegrationTest@7857fe2]
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.radial.hostedpayments.service.MailClientServiceIntegrationTest': Unsatisfied dependency expressed through field 'mailClientService': No qualifying bean of type [com.radial.hostedpayments.service.MailClientService] found for dependency [com.radial.hostedpayments.service.MailClientService]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.radial.hostedpayments.service.MailClientService] found for dependency [com.radial.hostedpayments.service.MailClientService]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:569) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:385) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118) ~[spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83) ~[spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.boot.test.autoconfigure.AutoConfigureReportTestExecutionListener.prepareTestInstance(AutoConfigureReportTestExecutionListener.java:46) ~[spring-boot-test-autoconfigure-1.4.0.RELEASE.jar:1.4.0.RELEASE]
        at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) [junit-4.12.jar:4.12]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) [junit-4.12.jar:4.12]
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) [junit-4.12.jar:4.12]
        at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363) [junit-4.12.jar:4.12]
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191) [spring-test-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:367) [surefire-junit4-2.19.1.jar:2.19.1]
        at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:274) [surefire-junit4-2.19.1.jar:2.19.1]
        at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238) [surefire-junit4-2.19.1.jar:2.19.1]
        at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:161) [surefire-junit4-2.19.1.jar:2.19.1]
        at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:290) [surefire-booter-2.19.1.jar:2.19.1]
        at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:242) [surefire-booter-2.19.1.jar:2.19.1]
        at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:121) [surefire-booter-2.19.1.jar:2.19.1]
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.radial.hostedpayments.service.MailClientService] found for dependency [com.radial.hostedpayments.service.MailClientService]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1406) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1057) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:566) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
        ... 30 more
Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 1.318 sec <<< FAILURE! - in com.radial.hostedpayments.service.MailClientServiceIntegrationTest
shouldSendMail(com.radial.hostedpayments.service.MailClientServiceIntegrationTest)  Time elapsed: 0.002 sec  <<< ERROR!
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.radial.hostedpayments.service.MailClientServiceIntegrationTest': Unsatisfied dependency expressed through field 'mailClientService': No qualifying bean of type [com.radial.hostedpayments.service.MailClientService] found for dependency [com.radial.hostedpayments.service.MailClientService]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.radial.hostedpayments.service.MailClientService] found for dependency [com.radial.hostedpayments.service.MailClientService]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.radial.hostedpayments.service.MailClientService] found for dependency [com.radial.hostedpayments.service.MailClientService]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}


Results :

Tests in error:
  MailClientServiceIntegrationTest.shouldSendMail » UnsatisfiedDependency Error ...

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0

MailClientServiceIntegrationTest.java (product-integration-tests maven module)

@RunWith(SpringRunner.class)
public class MailClientServiceIntegrationTest {

    @Autowired
    private MailClientService mailClientService;
    private GreenMail smtpServer;

    @Before
    public void setUp() throws Exception {
        smtpServer = new GreenMail(new ServerSetup(25, null, "smtp"));
        smtpServer.start();
    }

    @Test
    public void shouldSendMail() throws Exception {
        //given
        String recipient = "name@dolszewski.com";
        String message = "Test message content";
        //when
        mailClientService.prepareAndSend(recipient, message);
        //then
        assertReceivedMessageContains(message);
    }

    private void assertReceivedMessageContains(String expected) throws IOException, MessagingException {
        MimeMessage[] receivedMessages = smtpServer.getReceivedMessages();
        assertEquals(1, receivedMessages.length);
        String content = (String) receivedMessages[0].getContent();
        assertTrue(content.contains(expected));
    }

    @After
    public void tearDown() throws Exception {
        smtpServer.stop();
    }

}

MailClientService.java (product-service maven module)

@Service
public class MailClientService {

    @Autowired
    private JavaMailSender mailSender;
    private MailContentBuilder mailContentBuilder;

    @Value("${error.email.from.address}")
    private String emailAddressFrom;
    @Value("${error.email.to.address}")
    private String emailRecipientAddress;

    private String[] emailRecipientAddresses;
    private static final boolean HTML_FLAG = true;
    private static final String ERROR_ALERT_EMAIL_SUBJECT = "Hosted Payment Service - Error Alert on ";
    private static final Logger LOGGER = LoggerFactory.getLogger(MailClientServiceImpl.class);

    public MailClientServiceImpl(final JavaMailSender javaMailSender, final MailContentBuilder emailContentBuilder) {
        this.mailSender = javaMailSender;
        this.mailContentBuilder = emailContentBuilder;
    }

    @Override
    public void prepareAndSend(final String message, final String emailSubject) {
        emailRecipientAddresses = StringUtils.split(emailRecipientAddress, ',');
        MimeMessagePreparator messagePreparator = mimeMessage -> {
            MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage);
            messageHelper.setFrom(emailAddressFrom);
            messageHelper.setTo(emailRecipientAddresses);
            if (StringUtils.isNotBlank(emailSubject)) {
                messageHelper.setSubject(emailSubject);
            } else {
                messageHelper.setSubject(ERROR_ALERT_EMAIL_SUBJECT + CommonUtils.getHostName());
            }

            // Create the HTML body using Thymeleaf
            String htmlContent = mailContentBuilder.buildHtmlTemplating(message);
            messageHelper.setText(htmlContent, HTML_FLAG);
        };

        try {
            // Send email
            if (LOGGER.isDebugEnabled()) {
                LOGGER.debug("Sending email '{}' to: {} ", ERROR_ALERT_EMAIL_SUBJECT, emailRecipientAddress);
            }
            mailSender.send(messagePreparator);
        } catch (MailException e) {
                e.printStackTrace();
                LOGGER.error("Problem with sending alert email to: {}, error message: {}", emailRecipientAddress, e.getMessage());
        }
    }

    @Override
    public void prepareAndSend(final String message) {
        prepareAndSend(message, null);
    }

}     

product-web/pom.xml

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>3.1.0</version>
    <configuration>
        <attachClasses>true</attachClasses>
    </configuration>
</plugin>

product-integration-tests/pom.xml

<dependency>
    <groupId>${project.groupId}</groupId>
    <artifactId>hosted-payments</artifactId>
    <version>${project.version}</version>
    <classifier>classes</classifier>
</dependency>

Answer 1

If you look closely, you can create an instance of the MailClientService, but Spring just can't inject an instance in your test class through the @Autowired annotation:

No qualifying bean of type [com.radial.hostedpayments.service.MailClientService] found for dependency [com.radial.hostedpayments.service.MailClientService]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException

You need to provide Spring bean instances of your MailClientService class available to your test class. This can be done through the @ContextConfiguration annotation.

Step 1 - create a @Configuration class that exposes your MailServiceClient :

@Configuration
public class TestConfig {

    @Bean
    public JavaMailSender mailSender() {
       // example of returning a mock object 
       return Mockito.mock(JavaMailSender.class);
    }    

    @Bean
    public GreenMail smtpServer() {
       // another mock
       return Mockito.mock(GreenMail.class);
    }

    @Bean
    public MailClientService mailClientService(){
        // this could also be used to return a Mock object
        return new MailClientService();
    }
}

Step 2 - Add the configuration class to your test:

...
@ContextConfiguration(classes = {TestConfig.class})
public class MailClientServiceIntegrationTest {
...

I've edited this to show how you can return mocks from your config class. Note that in your implementation, you have the autowired the JavaMailSender, but not the GreenMail variable.

Another (probably simpler option) would be to use the @MockBean annotation instead of autowiring as described in the Spring Boot testing doc (section 41.3.4)