TDD Architecture Patterns

Software architecture should enable testing, not hinder it. These patterns ensure your system remains decoupled and verifiable.

Core Patterns

1. Hexagonal Architecture (Ports & Adapters)

• Keep your business logic (the Core) isolated from external concerns (DB, UI, APIs).
• Use Ports (interfaces) for the core to communicate with the outside world.
• Use Adapters to implement those ports for specific technologies.

2. Dependency Injection (DI)

• Invert the control of dependencies. Instead of a class creating its helper, it receives it via a constructor or parameter.
• Benefit: Allows you to easily swap real dependencies with mocks in tests.