Book Image

Test-Driven iOS Development with Swift - Fourth Edition

By : Dr. Dominik Hauser
Book Image

Test-Driven iOS Development with Swift - Fourth Edition

By: Dr. Dominik Hauser

Overview of this book

Test-driven development (TDD) is a proven way to find software bugs earlier on in software development. Writing tests before you code improves the structure and maintainability of your apps, and so using TDD in combination with Swift 5.5's improved syntax leaves you with no excuse for writing bad code. Developers working with iOS will be able to put their knowledge to work with this practical guide to TDD in iOS. This book will help you grasp the fundamentals and show you how to run TDD with Xcode. You'll learn how to test network code, navigate between different parts of the app, run asynchronous tests, and much more. Using practical, real-world examples, you'll begin with an overview of the TDD workflow and get to grips with unit testing concepts and code cycles. You'll then develop an entire iOS app using TDD while exploring different strategies for writing tests for models, view controllers, and networking code. Additionally, you'll explore how to test the user interface and business logic of iOS apps and even write tests for the network layer of the sample app. By the end of this TDD book, you'll be able to implement TDD methodologies comfortably in your day-to-day development for building scalable and robust applications.
Table of Contents (17 chapters)
Section 1 –The Basics of Test-Driven iOS Development
Section 2 –The Data Model
Section 3 –Views and View Controllers
Section 4 –Networking and Navigation

Chapter 6: Testing, Loading, and Saving Data

At the moment, we have structures to hold the information of one to-do item. A usable to-do item app has to show and manage several to-do items. In addition, when the user closes the app and opens it again, they expect the to-do items to still be there.

This means our app needs structures that can store and load information of a list of to-do items.

In this chapter, we will add a class that stores and loads a list of to-do items to and from the filesystem of the iOS device. We will use the JSON format because it is a common choice in iOS development. It has the nice benefit in that it is easily readable by humans and computers.

The chapter is structured as follows:

  • Publishing changes with Combine
  • Checking items
  • Storing and loading ToDoItem