dependency-inversion-principle

What problem does it solve?

DIP helps teams build flexible, testable code by avoiding high-level modules creating their own concrete dependencies.

Core Features & Use Cases

• Interface Abstractions: Define contracts for dependencies.
• Constructor Injection & DI: Wire dependencies via constructors rather than instantiating them.
• Testability & Modularity: Easily mock or replace services during tests or when swapping providers.
• Use Case: You have a UserService that uses EmailService and UserRepository; refactor to inject interfaces and a composition root to wire implementations, enabling unit tests without real external services.

Quick Start

Define interfaces for external services, convert concrete dependencies to abstractions, and wire implementations via a composition root to avoid instantiating concrete classes inside high-level modules.