Implementing Domain-Driven Design

Testing Value Objects

To emphasize test-first, I first present sample tests before I provide the Value Object implementation. These tests drive the domain model’s design by providing examples of how a client will use each object.

Employing this style, we are not as interested in addressing the various aspects of unit testing, thoroughly proving that the model is completely bulletproof in every way. Rather, at this point in time there is more interest in demonstrating how various objects in the domain model will be used by clients and what those clients can expect when they use them. It is essential to assume the client’s perspective when designing the model in order to capture the essential concepts. Otherwise, we could be modeling from our ...