Summary
Domain-Driven Design (DDD) is an approach to software development that emphasizes deep understanding of the business. DDD aligns the software model with real-world concepts.
Domain Services encapsulate business logic that doesn't naturally fit within an entity or value object. Repositories provide an abstraction for retrieving and persisting aggregates. Application Services orchestrate workflows.
I'd like to see how these tests would be applied to other languages such as C and C++. I'd also like to know how they would be tested in the future.