unity-testability

To separate MonoBehaviour logic for unit testing, move game logic into plain C# classes, leaving Unity-facing classes to handle component lifecycle. This creates testable boundaries, enabling direct unit testing of logic without MonoBehaviour dependencies.

EditMode tests run without the Unity engine lifecycle, ideal for testing pure C# logic quickly. PlayMode tests run inside the engine, suitable for integration testing. Separating logic into plain C# components maximizes EditMode coverage.

Introduce interfaces and mocking when external dependencies or Unity API calls prevent direct unit testing. Defining testable boundaries with interfaces allows test doubles to isolate plain C# logic during EditMode and PlayMode tests.

Yes, dependency injection improves Unity testability by injecting plain C# dependencies into MonoBehaviour. This architecture planning strategy allows swapping real implementations with mocks for isolated unit testing.

The best way to plan Unity refactoring test strategy is enforcing a decision framework for where logic lives. Move responsibilities to plain C# components and use EditMode tests for logic, reserving PlayMode tests for integration.