Book Image

How to Build Android Apps with Kotlin - Second Edition

By : Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal
5 (1)
Book Image

How to Build Android Apps with Kotlin - Second Edition

5 (1)
By: Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal

Overview of this book

Looking to kick-start your app development journey with Android 13, but don’t know where to start? How to Build Android Apps with Kotlin is a comprehensive guide that will help jump-start your Android development practice. This book starts with the fundamentals of app development, enabling you to utilize Android Studio and Kotlin to get started with building Android projects. You'll learn how to create apps and run them on virtual devices through guided exercises. Progressing through the chapters, you'll delve into Android's RecyclerView to make the most of lists, images, and maps, and see how to fetch data from a web service. You'll also get to grips with testing, learning how to keep your architecture clean, understanding how to persist data, and gaining basic knowledge of the dependency injection pattern. Finally, you'll see how to publish your apps on the Google Play store. You'll work on realistic projects that are split up into bitesize exercises and activities, allowing you to challenge yourself in an enjoyable and attainable way. You'll build apps to create quizzes, read news articles, check weather reports, store recipes, retrieve movie information, and remind you where you parked your car. By the end of this book, you'll have the skills and confidence to build your own creative Android applications using Kotlin.
Table of Contents (24 chapters)
1
Part 1: Android Foundation
6
Part 2: Displaying Network Calls
12
Part 3: Testing and Code Structure
17
Part 4: Polishing and Publishing an App

Mockito

In the preceding examples, we looked at how to set up a unit test and how to use assertions to verify the result of an operation. What if we want to verify whether a certain method was called? Or what if we want to manipulate the test input to test a specific scenario? In these types of situations, we can use Mockito.

This is a library that helps developers set up dummy objects that can be injected into the objects under test and allows them to verify method calls, set up inputs, and even monitor the test objects themselves.

The library should be added to your test Gradle setup, as follows:

testImplementation 'org.mockito:mockito-core:4.5.1'

Now, let’s look at the following code example (please note that, for brevity, import statements have been removed from the following code snippets):

class StringConcatenator(private val context: Context) {
    fun concatenate(@StringRes stringRes1: Int,
     &...