nullable-architecture

Behavior simulation in testing replaces mocks by tracking observable outputs through infrastructure wrappers. The Nullables approach uses .create() and .createNull() for explicit construction, allowing state-based tests to verify interactions without side effects or mock frameworks.

The Nullables approach models real and test environments using explicit construction with new, .create(), and .createNull(). It places infrastructure wrappers at the environment boundary to decouple code from I/O and verify behavior through observable output tracking.

Start by wiring a real class with a real dependency via .create() and a nulled dependency via .createNull() in a minimal test. Assert observable outputs using a clear Arrange-Act-Assert structure to verify behavior without side effects.

Yes, the Nullables testing pattern requires infrastructure wrappers at the environment boundary. These wrappers must expose .create() and .createNull() methods and support configurable null-dependencies to properly decouple code from I/O operations.

Observable output tracking verifies interactions by checking outputs rather than setting up mock expectations. This state-based approach keeps tests sociable and readable, validating behavior simulation without side effects while promoting safe refactoring.

Yes, the Nullables pattern applies to unit and integration tests across environments. It uses explicit construction to model real versus test environments, relying on infrastructure wrappers to maintain consistent behavior simulation and output tracking.