Book Image

Test-Driven iOS Development with Swift 4 - Third Edition

By : Dr. Dominik Hauser
Book Image

Test-Driven iOS Development with Swift 4 - Third Edition

By: Dr. Dominik Hauser

Overview of this book

Test-driven development (TDD) is a proven way to find software bugs early. Writing tests before you code improves the structure and maintainability of your apps. Using TDD, in combination with Swift 4's improved syntax, means there is no longer any excuse for writing bad code. This book will help you understand the process of TDD and how to apply it to your apps written in Swift. Through practical, real-world examples, you’ll learn how to implement TDD in context. You will begin with an overview of the TDD workflow and then delve into unit-testing concepts and code cycles. You will also plan and structure your test-driven iOS app, and write tests to drive the development of view controllers and helper classes. Next, you’ll learn how to write tests for network code and explore how the test-driven approach—in combination with stubs—helps you write network code even before the backend component is finished. Finally, the book will guide you through the next steps to becoming a testing expert by discussing integration tests, Behavior Driven Development (BDD), open source testing frameworks, and UI Tests (introduced in Xcode 9).
Table of Contents (9 chapters)


In this chapter, we took a look at how to implement the model layer of our app using TDD. We followed the TDD workflow (red, green, and refactor) to guide the implementation of the required micro features.

We implemented two model structs and a manager class. We added conformance to the Equatable protocol for the model structs in order to make sure that the same to-do item cannot be added to the list more than once. We also encapsulated the internals of the manager class with methods to add, receive, and remove to-do items from the manager.

TDD led us to a clean, simple, and fully-tested model.

In the next chapter, we will implement the controller layer and the view layer following the Model-View-Controller design pattern using TDD.