Book Image

Test-Driven iOS Development with Swift - Fourth Edition

By : Dr. Dominik Hauser
5 (1)
Book Image

Test-Driven iOS Development with Swift - Fourth Edition

5 (1)
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

Storing and loading ToDoItems

To test storing and loading to-do items, we first need to create an instance of the ToDoItemStore class, add a to-do item, destroy that store instance, and create a new one. When we add a to-do item in the first instance, all items should be stored in the filesystem. When creating the second instance, the stored items should be loaded again from the filesystem. This means when we find the item we added in the first instance after we created the second instance, storing and loading works.

Implementing storing and loading

It is essential that the test controls the environment needed for itself. This means for storing and loading to-do items, the test needs to control where the items are stored. For example, if we used Core Data to persist the to-do items, the test would be responsible for setting up a fake Core Data store just used for the test. In our app, we will store the to-do items in a JSON file. So, the test needs to control where the JSON file...