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 much more domain oriented tests
- Make test setup and assertions much more domain expressive
- Eliminates mocking induced bugs
- Replaces mocks entirely
- Improved refactorability in the domain layer - by eliminating mocks
- Make infrastructure more replacable

Join us to practice writing adapter contract tests and the accompanying simulators.

We'll also reveal how we handle the potentially unstable full integration tests.