Summary

Testing an event-driven application is no harder than testing a monolithic application when you have a good testing strategy. In this chapter, we covered the application, domain, and business logic using unit tests. These tests make up the bulk of our testing force. We follow up our unit tests with integration tests, which help uncover issues with how our components interact. Using tools such as Testcontainers-Go can help reduce the effort required to run the tests, and using libraries such as the Testify suite can help reduce the test setup and teardown complexities.

A distributed application, whether it is event-driven like ours or synchronous, gains a lot from including contract testing in the testing strategy. Having confidence in how you are using or have made expectations of a provider without the mess and complexities of standing the provider up is a time saver many times over. Finally, including E2E testing in any form will give the team and stakeholders confidence...