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 9: Test-Driven Input View in SwiftUI

In 2019, Apple introduced SwiftUI as a new way to build user interfaces for apps on Apple platforms. In contrast to user interfaces built with UIKit, SwiftUI views are a function of some kind of state. As a result, testing such views can be very easy. In a test, we would have to set the state and assert that the expected user interface elements are present.

Unfortunately, the engineers in charge at Apple believe that there is no value in testing user interfaces. They believe that to prove the user interface looks and works as expected, it's enough to run the app and check with your eyes. This might be true for an app as simple as the one we are building in this book. But, if you have a look in the App Store, you will find most of the apps (if not all) are way more complicated. Usually, apps consist of many views and some of them are only visible in some rare cases. Ensuring that those views work for all input values and environment...