The separation between domain and infrastructure is key in DDD. We can exploit this interface even further through the little-known concept of Adapter Contract Testing. These tests not only thoroughly tests the infra layer in complete integration, but is also used to obtain perfect, intelligent simulators that can be used for the domain layer

Having simulators in which we have great confidence allows us to:
- Write more domain oriented tests
- Make test setup and assertions more domain expressive
- Eliminates mock-induced bugs
- Replaces mocks entirely
- Improved refactorability in the domain layer
- Make infrastructure more replacable

Join us to explore the power of Adapter Contract Testing and its versatile simulators, showcasing how they’ve transformed our testing and others' over the years.

We’ll also share how we manage—and even leverage—the challenges of unstable full integration tests.