Integration Test Implementation

Oct 13, 2025 by pinkandtrash.com 7 views

Why

The purpose of this integration test is to reproduce and fix the issue encountered on tmail.linagora.com with tmail-backend 1.0.3.1, where the EventDeadLettersRedeliverService failed to redeliver OpenSearch group events to RabbitMQ. The error message indicated that no event bus was associated with the event, which had an ID of b6de2078-1b41-430a-baa0-13e720d9e74b and belonged to the OpenSearchListeningMessageSearchIndexGroup group.

org.apache.james.webadmin.service.EventDeadLettersRedeliverService

No eventBus associated. event: EventId{id=b6de2078-1b41-430a-baa0-13e720d9e74b} for group: org.apache.james.mailbox.opensearch.events.OpenSearchListeningMessageSearchIndex$OpenSearchListeningMessageSearchIndexGroup

To address this issue, we will write an integration test in TMail that simulates OpenSearch indexing failures and reprocessing. This test will help us reproduce the issue and identify any necessary fixes.

HOW

To achieve this, we propose a scenario that involves the following steps:

Step 1: Pause RabbitMQ

The first step is to pause RabbitMQ, which will prevent events from being published to the message broker. This will simulate a scenario where events are not being delivered to RabbitMQ, resulting in dead letters.

Step 2: Add a Mail to a Mailbox

Next, we will add a mail to a mailbox. This will trigger the creation of events, which will be stored in the event bus.

Step 3: Expect Events Could Not Be Published to RabbitMQ

Since RabbitMQ is paused, we expect the events to be stored in the dead letter queue instead of being published to RabbitMQ.

Step 4: Unpause RabbitMQ

After pausing RabbitMQ, we will unpause it to simulate a scenario where the message broker is available again.

Step 5: Trigger Event Dead Letters Redelivery Service

With RabbitMQ unpause, we will trigger the EventDeadLettersRedeliverService to redeliver the events stored in the dead letter queue.

Step 6: Expect OpenSearch Listening Message Search Index Group Events to Get Delivered Well

Finally, we expect the OpenSearchListeningMessageSearchIndexGroup events to be delivered successfully to RabbitMQ.

Integration Test Implementation

To implement this integration test, we will use the following code:

import org.apache.james.webadmin.service.EventDeadLettersRedeliverService;
import org.apache.james.mailbox.opensearch.events.OpenSearchListeningMessageSearchIndexGroup;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.concurrent.TimeUnit;

@RunWith(SpringRunner.class)
@SpringBootTest
public class EventDeadLettersRedeliverServiceIntegrationTest {

    @Autowired
    private EventDeadLettersRedeliverService eventDeadLettersRedeliverService;

    @Autowired
    private OpenSearchListeningMessageSearchIndexGroup openSearchListeningMessageSearchIndexGroup;

    @Test
    public void testEventDeadLettersRedeliverService() throws InterruptedException {
        // Pause RabbitMQ
        // Add a mail to a mailbox
        // Expect events could not be published to RabbitMQ
        // Unpause RabbitMQ
        // Trigger EventDeadLettersRedeliverService
        // Expect OpenSearchListeningMessageSearchIndexGroup events to get delivered well
    }
}

Test Case Implementation

To implement the test case, we will use the following code:

@Test
public void testEventDeadLettersRedeliverService() throws InterruptedException {
    // Pause RabbitMQ
    rabbitMQ.pause();

    // Add a mail to a mailbox
    mailbox.addMail();

    // Expect events could not be published to RabbitMQ
    assertTrue(eventBus.getDeadLetterQueue().size() > 0);

    // Unpause RabbitMQ
    rabbitMQ.unpause();

    // Trigger EventDeadLettersRedeliverService
    eventDeadLettersRedeliverService.redeliverEvents();

    // Expect OpenSearchListeningMessageSearchIndexGroup events to get delivered well
    assertTrue(openSearchListeningMessageSearchIndexGroup.getEvents().size() > 0);
}

Conclusion

Q: What is the purpose of this integration test?

A: The purpose of this integration test is to reproduce and fix the issue encountered on tmail.linagora.com with tmail-backend 1.0.3.1, where the EventDeadLettersRedeliverService failed to redeliver OpenSearch group events to RabbitMQ.

Q: What is the scenario that this integration test simulates?

A: This integration test simulates a scenario where RabbitMQ is paused, a mail is added to a mailbox, and the events are stored in the dead letter queue. Then, RabbitMQ is unpause, and the EventDeadLettersRedeliverService is triggered to redeliver the events.

Q: What are the steps involved in this integration test?

A: The steps involved in this integration test are:

Pause RabbitMQ
Add a mail to a mailbox
Expect events could not be published to RabbitMQ
Unpause RabbitMQ
Trigger EventDeadLettersRedeliverService
Expect OpenSearch Listening Message Search Index Group events to get delivered well

Q: What is the expected outcome of this integration test?

A: The expected outcome of this integration test is that the EventDeadLettersRedeliverService successfully redelivers the OpenSearch Listening Message Search Index Group events to RabbitMQ.

Q: What is the benefit of this integration test?

A: The benefit of this integration test is that it helps to reproduce and fix the issue encountered on tmail.linagora.com with tmail-backend 1.0.3.1, where the EventDeadLettersRedeliverService failed to redeliver OpenSearch group events to RabbitMQ.

Q: How does this integration test ensure that the `EventDeadLettersRedeliverService` is working correctly?

A: This integration test ensures that the EventDeadLettersRedeliverService is working correctly by simulating a scenario where RabbitMQ is paused, a mail is added to a mailbox, and the events are stored in the dead letter queue. Then, RabbitMQ is unpause, and the EventDeadLettersRedeliverService is triggered to redeliver the events. The test expects the events to be delivered successfully to RabbitMQ.

Q: What are the potential issues that this integration test helps to identify?

A: This integration test helps to identify potential issues such as:

The EventDeadLettersRedeliverService is not working correctly
The events are not being stored in the dead letter queue correctly
The events are not being delivered successfully to RabbitMQ

Q: How can this integration test be modified to test other scenarios?

A: This integration test can be modified to test other scenarios by changing the steps involved in the test. For example, the test can be modified to simulate a scenario where RabbitMQ is not paused, or where the events are not stored in the dead letter queue correctly.

Q: What is the importance of this integration test in ensuring the reliability of the `EventDeadLettersRedeliverService`?

A: This integration test is important in ensuring the reliability of the EventDeadLettersRedeliverService because it helps to identify potential issues that may affect the delivery of events to RabbitMQ. By simulating a scenario where RabbitMQ is paused, a mail is added to a mailbox, and the events are stored in the dead letter queue, the test ensures that the EventDeadLettersRedeliverService is working correctly and that the events are delivered successfully to RabbitMQ.