Tests fail with #Scheduled Task: JdbcSQLSyntaxErrorException Table "USER_ACCOUNT_CREATED_EVENT" not found - spring

Question

Summary & first problem
I am trying to test my user registration mechanism. When a new user account is created via my REST API, a UserAccountCreatedEvent is stored in the database. A scheduled task checks the database every 5 seconds for new UserAccountCreatedEvents and if one is present, sends an email to the registered user. When running my tests I encounter the problem that the table for the UserAccountCreatedEvent can't be found (see exception below). I used to send the email in a blocking manner in the service method, but I recently switched to this async approach. All my tests worked perfectly for the blocking approach and the only thing I changed for the async approach is to include Awaitility in the test.
2019-04-23 11:24:51.605 ERROR 7968 --- [taskScheduler-1] o.s.s.s.TaskUtils$LoggingErrorHandler : Unexpected error occurred in scheduled task.
org.springframework.dao.InvalidDataAccessResourceUsageException: could not prepare statement; SQL [select useraccoun0_.id as id1_0_, useraccoun0_.completed_at as complete2_0_, useraccoun0_.created_at as created_3_0_, useraccoun0_.in_process_since as in_proce4_0_, useraccoun0_.status as status5_0_, useraccoun0_.user_id as user_id1_35_ from user_account_created_event useraccoun0_ where useraccoun0_.status=? order by useraccoun0_.created_at asc limit ?]; nested exception is org.hibernate.exception.SQLGrammarException: could not prepare statement
Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException:
Table "USER_ACCOUNT_CREATED_EVENT" not found; SQL statement:
select useraccoun0_.id as id1_0_, useraccoun0_.completed_at as complete2_0_, useraccoun0_.created_at as created_3_0_, useraccoun0_.in_process_since as in_proce4_0_, useraccoun0_.status as status5_0_, useraccoun0_.user_id as user_id1_35_ from user_account_created_event useraccoun0_ where useraccoun0_.status=? order by useraccoun0_.created_at asc limit ? [42102-199]
Full stack trace
Second problem
As if that were not enough, the tests behave completely different when running them in debug mode. When I set a breakpoint in the method that is called by the method which is annotated with #Scheduled, it is invoked several times althogh #Scheduled is configured with a fixedDelayString (fixed delay) of 5000ms. Thanks to logging I can even see that several mails were sent. Still, my test SMTP sever (GreenMail) does not receive any emails. How is this even possible? I've intentionally set the transaction isolation to Isolation.SERIALIZABLE so that it should be impossible (as far as I understand transaction isolation) that two scheduled methods access the same Event from the database.
Third problem
To cap it all, when I rerun the failed tests, THEY WORK. But, there are different exceptions on the console (see below). But still, the app starts and the tests finish successfully. There are different test results depending on if I run all tests vs. only the class vs. only the method vs. rerun failed tests. I don't understand how such an indeterministic behaviour can be possible.
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: Failed to scan classpath for unlisted entity classes
Caused by: java.nio.channels.ClosedByInterruptException: null
Full stack trace
My code
Test class (UserRegistrationTest)
#ActiveProfiles("test")
#AutoConfigureMockMvc
#RunWith(SpringRunner.class)
#SpringBootTest
#DirtiesContext(classMode = DirtiesContext.ClassMode.BEFORE_EACH_TEST_METHOD)
public class UserRegistrationTest {
#Autowired
private MockMvc mockMvc;
#Autowired
private ObjectMapper objectMapper;
#Autowired
private Routes routes;
#Autowired
private TestConfig testConfig;
#Resource(name = "validCustomerDTO")
private CustomerDTO validCustomerDTO;
#Resource(name = "validVendorDTO")
private VendorRegistrationDTO validVendorRegistrationDTO;
#Value("${schedule.sendRegistrationConfirmationEmailTaskDelay}")
private Short registrationConfirmationEmailSenderTaskDelay;
private GreenMail smtpServer;
// Setup & tear down
#Before
public void setUp() {
smtpServer = testConfig.getMailServer();
smtpServer.start();
}
#After
public void tearDown() {
smtpServer.stop();
}
// Tests
#Test
public void testCreateCustomerAccount() throws Exception {
mockMvc.perform(
post(routes.getCustomerPath())
.contentType(MediaType.APPLICATION_JSON_UTF8)
.content(objectMapper.writeValueAsString(validCustomerDTO)))
.andExpect(status().isCreated());
// When run normally, I get a timeout from the next line
await().atMost(registrationConfirmationEmailSenderTaskDelay + 10000, MILLISECONDS).until(smtpServerReceivedOneEmail());
// Verify correct registration confirmation email was sent
MimeMessage[] receivedMessages = smtpServer.getReceivedMessages();
assertThat(receivedMessages).hasSize(1);
// other checks
// ...
}
#Test
public void testCreateVendorAccount() throws Exception {
mockMvc.perform(
post(routes.getVendorPath())
.contentType(MediaType.APPLICATION_JSON_UTF8)
.content(objectMapper.writeValueAsString(validVendorRegistrationDTO)))
.andExpect(status().isCreated());
// When run normally, I get a timeout from the next line
await().atMost(registrationConfirmationEmailSenderTaskDelay + 10000, MILLISECONDS).until(smtpServerReceivedOneEmail());
// Verify correct registration confirmation email was sent
MimeMessage[] receivedMessages = smtpServer.getReceivedMessages();
assertThat(receivedMessages).hasSize(1);
// other checks
// ...
}
// Helper methods
private Callable<Boolean> smtpServerReceivedOneEmail() {
return () -> smtpServer.getReceivedMessages().length == 1;
}
// Test configuration
#TestConfiguration
static class TestConfig {
private static final int PORT = 3025;
private static final String HOST = "localhost";
private static final String PROTOCOL = "smtp";
GreenMail getMailServer() {
return new GreenMail(new ServerSetup(PORT, HOST, PROTOCOL));
}
#Bean
public JavaMailSender javaMailSender() {
JavaMailSenderImpl javaMailSender = new JavaMailSenderImpl();
javaMailSender.setHost(HOST);
javaMailSender.setPort(PORT);
javaMailSender.setProtocol(PROTOCOL);
javaMailSender.setDefaultEncoding("UTF-8");
return javaMailSender;
}
}
Task scheduler (BusinessTaskScheduler)
#Component
public class BusinessTaskScheduler {
private final RegistrationTask registrationTask;
#Autowired
public BusinessTaskScheduler(RegistrationTask registrationTask) {
this.registrationTask = registrationTask;
}
#Scheduled(fixedDelayString = "${schedule.sendRegistrationConfirmationEmailTaskDelay}")
public void sendRegistrationConfirmationEmail() {
registrationTask.sendRegistrationConfirmationEmail();
}
}
The code that is called by the scheduled method (RegistrationTask)
#Component
#Transactional(isolation = Isolation.SERIALIZABLE)
public class RegistrationTask {
private final EmailHelper emailHelper;
private final EventService eventService;
private final UserRegistrationService userRegistrationService;
#Autowired
public RegistrationTask(EmailHelper emailHelper, EventService eventService, UserRegistrationService userRegistrationService) {
this.emailHelper = emailHelper;
this.eventService = eventService;
this.userRegistrationService = userRegistrationService;
}
public void sendRegistrationConfirmationEmail() {
Optional<UserAccountCreatedEvent> optionalEvent = eventService.getOldestUncompletedUserAccountCreatedEvent();
if (optionalEvent.isPresent()) {
UserAccountCreatedEvent event = optionalEvent.get();
User user = event.getUser();
RegistrationVerificationToken token = userRegistrationService.createRegistrationVerificationTokenForUser(user);
emailHelper.sendRegistrationConfirmationEmail(token);
eventService.completeEvent(event);
}
}
}
The event service (EventServiceImpl)
#Service
#Transactional(isolation = Isolation.SERIALIZABLE)
public class EventServiceImpl implements EventService {
private final ApplicationEventDAO applicationEventDAO;
private final UserAccountCreatedEventDAO userAccountCreatedEventDAO;
#Autowired
public EventServiceImpl(ApplicationEventDAO applicationEventDAO, UserAccountCreatedEventDAO userAccountCreatedEventDAO) {
this.applicationEventDAO = applicationEventDAO;
this.userAccountCreatedEventDAO = userAccountCreatedEventDAO;
}
#Override
public void completeEvent(ApplicationEvent event) {
if (!event.getStatus().equals(COMPLETED) && Objects.isNull(event.getCompletedAt())) {
event.setStatus(COMPLETED);
event.setCompletedAt(LocalDateTime.now());
applicationEventDAO.save(event);
}
}
#Override
public Optional<UserAccountCreatedEvent> getOldestUncompletedUserAccountCreatedEvent() {
Optional<UserAccountCreatedEvent> optionalEvent = userAccountCreatedEventDAO.findFirstByStatusOrderByCreatedAtAsc(NEW);
if (optionalEvent.isPresent()) {
UserAccountCreatedEvent event = optionalEvent.get();
setEventInProcess(event);
return Optional.of(userAccountCreatedEventDAO.save(event));
}
return Optional.empty();
}
#Override
public void publishEvent(ApplicationEvent event) {
applicationEventDAO.save(event);
}
// Helper methods
private void setEventInProcess(ApplicationEvent event) {
event.setStatus(Status.IN_PROCESS);
event.setInProcessSince(LocalDateTime.now());
}
}
The UserAccountCreatedEvent
application.yml
schedule:
sendRegistrationConfirmationEmailTaskDelay: 5000 # delay between tasks in milliseconds
I am new to scheduling with Spring, so any help is greatly appreciated!