convention-law-of-demeter

The Law of Demeter is a design principle dictating that an object should interact only with its direct collaborators. It prevents deep method call chains like a.b.c.d, reducing tight coupling and improving code maintainability.

To refactor deeply nested method chains, replace chained calls with direct access to needed collaborators or introduce a small facade. This limits knowledge of internal structures and enforces shallow object interactions for better testability.

Deep object coupling makes code fragile because changes to internal structures ripple through deep call chains. Limiting interactions to direct collaborators isolates changes, ensuring that modifications do not break unrelated dependent modules.

Apply the Law of Demeter during code refactoring when you identify deep call chains increasing object coupling. Use it to enforce shallow interactions in service layers, ensuring objects communicate only with immediate dependencies.

Yes, you can use a small facade to fix Law of Demeter violations. Providing a simple facade interface hides internal structures and reduces deep object coupling by allowing objects to interact with direct dependencies only.

A limitation of enforcing strict object coupling rules is the potential need to create numerous wrapper or facade methods. This can increase boilerplate code, requiring careful judgment to balance reduced coupling against interface bloat.