Testing the event-driven modular monolith
Now that we have implemented the events, before moving on to the next topic, it is important to understand how to effectively test aggregates with events.
It is good to remember the safety net principle from Chapter 5. Without comprehensive tests in place, you risk breaking critical functionalities, making the system unstable during refactoring. Especially in a CQRS+ES architecture, where commands and events shape the system’s state, robust tests are your guardrails. Testing becomes more intricate than in traditional systems because you need to verify not just the behavior of individual components but also how events ripple through the system.
In this context, specification testing emerges as the ideal approach.
Specification tests
Unlike unit tests, which focus on isolated methods or classes, specification tests target the entire lifecycle of an aggregate by simulating real-world scenarios. This is crucial because your...
