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 a login request

Let's assume that a colleague is developing a web service, but it is not finished yet. However, we already know what the API will look like. There will be an endpoint for the login. The URL will be; it will take two parameters: a username and password, and it will return a token that has to be used with each further call to the API.

We need a test that asserts that the token that is returned from the login call is put into a token struct.

Add a new iOS | Source | Unit Test Case Class, and call it APIClientTests. Import the main module so that it can be tested (@testable import ToDo), and remove the two template tests.

We will split the login feature into several micro features. As mentioned previously, the login should make an HTTPS request to with the username and password as query...