Hide Delegate

Goal

Callers ask the closest object for what they want; the object delegates internally without exposing its collaborators.

Before the refactoring

const street = order.customer.address.street;

After the refactoring

// inside Order: customerStreet() { return this.customer.address.street; }
const street = order.customerStreet();

Savings

Encapsulation tightens; intermediate objects can change shape without breaking callers.

Note

Adds a passthrough method on the parent for every delegated operation — only worth it for operations that are repeated across consumers.