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)

Functional tests

Until now, we have written unit tests to drive the implementation. Unit tests test a small microfeature (a unit of the project) under controlled circumstances.

On the other side of the spectrum are functional tests, which test the functionalities of the app in terms of how a user would approach them. The user does not care how the app they're using is implemented. The user cares about what they can do with the app. Functional tests help make sure that the app works as expected.

In this section, we will add a functional test using UI tests, which were introduced with Xcode 7. We will take one functionality (adding a to-do item) and write a test from the user's perspective.

Adding a UI test target