Test-driven iOS development with Swift 3 write testable and maintainable code to develop highly-functional iOS apps

210 Pages·2016·4.971 MB·English

by  Hauser, Dominik

Test-Driven iOS Development with
Swift 3

Write testable and maintainable code to develop highly-functional iOS apps

Dr. Dominik Hauser

BIRMINGHAM - MUMBAI
Test-Driven iOS Development with Swift 3

Copyright © 2016 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or
transmitted in any form or by any means, without the prior written permission of the
publisher, except in the case of brief quotations embedded in critical articles or reviews.
Every effort has been made in the preparation of this book to ensure the accuracy of the
information presented. However, the information contained in this book is sold without
warranty, either express or implied. Neither the author, nor Packt Publishing, and its
dealers and distributors will be held liable for any damages caused or alleged to be caused
directly or indirectly by this book.
Packt Publishing has endeavored to provide trademark information about all of the
companies and products mentioned in this book by the appropriate use of capitals.
However, Packt Publishing cannot guarantee the accuracy of this information.
First published: February 2015
Second edition: October 2016
Production reference: 1251016
Published by Packt Publishing Ltd.
Livery Place
35 Livery Street
Birmingham
B3 2PB, UK.
ISBN 978-1-78712-907-8
www.packtpub.com
Credits
Author Copy Editor

Dr. Dominik Hauser Yesha Gangani
Reviewer Project Coordinator

S Ravi Shankar Sheejal Shah
Commissioning Editor Proofreader

Ashwin Nair Safis Editing
Acquisition Editor Indexer

Reshma Raman Rekha Nair
Content Development Editor Production Coordinator

Parshva Sheth Aparna Bhagat
Technical Editor

Rutuja Vaze
About the Author
Dr. Dominik Hauser completed his Ph.D. from the University of Heidelberg in Physics.
While working as a university professor, he started iOS development in his spare time. His
first app on Physics has been an astounding success worldwide. Since then, he turned
himself into a full-time iOS developer, crediting number of successful apps to his name. He
has been a Swift developer since day one and runs a blog on iOS development,
www.swiftandpainless.com.
I would like to thank my wife, Isa. Thank you for all your support during all those years
and especially the last months while I wrote this book. I also want to thank all those great
people in our community. I learned so much by reading excellent blog posts. I proud to be
part of it.
About the Reviewer
S Ravi Shankar is a multi-skilled software consultant with over 17+ years of experience in
IT Industry. Good all-around ability to work in different technologies and extensive
experience in product development, system maintenance and support. A polyglot and a
self-taught programmer with hands on experience in Swift, Objective-C and Java.
It was a pleasure to work with Sheejal and thanks to Packt publishing for giving me this
opportunity.
www.PacktPub.com
For support files and downloads related to your book, please visit www.PacktPub.com.
Did you know that Packt offers eBook versions of every book published, with PDF and
ePub files available? You can upgrade to the eBook version at www.PacktPub.com and as a
print book customer, you are entitled to a discount on the eBook copy. Get in touch with us
at [email protected] for more details.
At www.PacktPub.com, you can also read a collection of free technical articles, sign up for a
range of free newsletters and receive exclusive discounts and offers on Packt books and
eBooks.
https://www.packtpub.com/mapt

Get the most in-demand software skills with Mapt. Mapt gives you full access to all Packt
books and video courses, as well as industry-leading tools to help you plan your personal
development and advance your career.
Why subscribe?
Fully searchable across every book published by Packt
Copy and paste, print, and bookmark content
On demand and accessible via a web browser
Table of Contents
Preface
1
Chapter 1: Your First Unit Tests
6
Building your first automatic unit test 7
What are unit tests? 7
Implementing a unit test example 7
Important built-in assert functions 12
Understanding TDD 15
The TDD workflow – red, green, and refactor 16
Red 16
Green 17
Refactor 17
TDD in Xcode 17
An example of TDD 18
Red – example 1 19
Green – example 1 20
Refactor – example 1 20
Red – example 2 21
Green – example 2 21
Refactor – example 2 22
A recap 24
Finding information about tests in Xcode 24
Test Navigator 24
Tests overview 25
Running tests 27
Running one specific test 27
Running all tests in a test case 28
Running a group of tests 28
The setUp() and tearDown() methods 29
Debugging tests 30
Breakpoint that breaks on test failure 31
The test again feature 32
The advantages of TDD 32
The disadvantages of TDD 33
What to test 34
Summary 35
Chapter 2: Planning and Structuring Your Test-Driven iOS App
36
The task list view 37
The task detail view 39
The task input view 40
The structure of the app 41
The Table View Controller, the delegate, and the data source 41
Table view cells 42
The model 42
Other View Controllers 42
The development strategy 43
Getting started with Xcode 43
Setting up useful Xcode behaviors for testing 44
Useful build behaviors 45
Testing behaviors 45
Summary 47
Chapter 3: A Test-Driven Data Model
48
Implementing the ToDoItem struct 49
Adding a title property 49
Adding an itemDescription property 51
Removing a hidden source of bugs 52
Adding a timestamp property 54
Adding a location property 55
Implementing the Location struct 56
Adding a coordinate property 57
Implementing the ItemManager class 58
Count 58
Adding and checking items 61
Equatable 67
Removing all items 76
Ensuring uniqueness 77
Summary 78
Chapter 4: A Test-Driven View Controller
79
Implementing ItemListViewController 80
Implementing ItemListDataProvider 90
Conducting the first tests 90
Fake objects 96
Using mocks 97
Checking and unchecking items 108
Implementing ItemCell 110
Implementing DetailViewController 117
[ ii ]
Implementing InputViewController 122
Summary 128
Chapter 5: Testing Network Code
129
Implementing tests using a web service 130
Implementing a login request 133
Handling errors 141
Summary 145
Chapter 6: Putting It All Together
146
Connecting parts 147
The initial View Controller 147
Showing the input view 148
Showing the detail view 156
Serialization and deserialization 160
Functional tests 168
Adding a UI test target 169
Recording and testing 169
Summary 175
Chapter 7: Code Coverage and Continuous Integration
176
Enabling code coverage 176
Code coverage in Xcode 177
What code coverage is enough? 180
Continuous integration 180
Installing and setting up Xcode Server 181
Adding bots 186
Automatic deployment with fastlane 190
Installing fastlane 191
Setting up 191
Summary 192
Chapter 8: Where to Go from Here
193
What we have learned so far 193
Integration tests 194
UI tests 194
Behavior-Driven Development 195
TDD in existing projects 196
More information about TDD 197
Summary 197
Index
198
[ iii ]