Clean Code in Swift: iOS and macOS Development

The book «Clean Code in Swift (iOS/macOS)» is a practical guide for developers who want to write code that is easy to read, maintain, and extend. Inspired by the ideas of Robert Martin, the author adapts the principles of clean code to the Apple ecosystem, taking into account the features of the Swift language, the UIKit and SwiftUI frameworks, and the iOS/macOS platforms.

What is this book about?

The book covers all key aspects of writing quality code in Swift:

• Principles of Clean Code: meaningful names, small functions, no side effects, comments only where they are truly needed.
• SOLID in Swift: applying the principles of single responsibility, open/closed, Liskov substitution, interface segregation, and dependency inversion in real projects.
• Architectural Patterns: MVC, MVP, MVVM, VIPER, and Coordinator — how to choose and implement them without pain.
• Refactoring: step-by-step techniques for improving existing code, from simple renaming to extracting protocols and implementing dependency injection.
• Testing: unit tests, UI tests, mock objects, and TDD (Test-Driven Development) using iOS/macOS applications as examples.
• Memory Management and Performance: avoiding retain cycles, proper use of weak/unowned, optimizing closures and data structures.
• SwiftUI vs UIKit: how to write clean code in declarative and imperative styles without mixing approaches.

Who is this book for?

• Junior and Middle iOS/macOS developers who want to stop writing "spaghetti code" and start building professional projects.
• Developers transitioning from other languages (Java, C#, Python) to Swift — the book will help quickly master local standards and idioms.
• Team leads and architects looking for tools for code review and implementing quality standards within the team.

What will you learn after reading?

• How to write functions that do one thing and do it well.
• How to avoid "magic numbers," duplication, and long methods.
• How to build an architecture that isn't scary to change six months later.
• How to write tests that actually help, rather than slow down development.
• How to refactor legacy code without fear of breaking everything.
• How to use Swift features (extension, protocol, generics) for clean design.

The book contains many code examples, analysis of common mistakes, and practical exercises. After each chapter, there is a self-check checklist and assignments to reinforce the material.

«Clean Code in Swift» is not a syntax reference, but a development philosophy that will transform you from a mere programmer into an engineer creating products that people want to maintain.