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)

Implementing DetailViewController

We start the implementation of DetailViewController with the creation of a test case. Select the ToDoTests group in Project Navigator and go to iOS | Source | Unit Test Case Class. Let's name it DetailViewControllerTests, and select the Controller folder as the destination location. Import the @testable import ToDo main module and delete the two template test methods.

Going by the screenshots we've seen in Chapter 2, Planning and Structuring Your Test-Driven iOS App, we know that DetailViewController needs a map view, four labels, and a button. Here, we will only show the TDD process for one label and the button. Add the following code to DetailViewControllerTests:

func test_HasTitleLabel() { 
  let storyboard = UIStoryboard(name: "Main", 
                                bundle: nil) 
  let sut = storyboard