Book Image

Kotlin Standard Library Cookbook

By : Samuel Urbanowicz
Book Image

Kotlin Standard Library Cookbook

By: Samuel Urbanowicz

Overview of this book

For developers who prefer a more simplistic approach to coding, Kotlin has emerged as a valuable solution for effective software development. The Kotlin standard library provides vital tools that make day-to-day Kotlin programming easier. This library features core attributes of the language, such as algorithmic problems, design patterns, data processing, and working with files and data streams. With a recipe-based approach, this book features coding solutions that you can readily execute. Through the book, you’ll encounter a variety of interesting topics related to data processing, I/O operations, and collections transformation. You’ll get started by exploring the most effective design patterns in Kotlin and understand how coroutines add new features to JavaScript. As you progress, you'll learn how to implement clean, reusable functions and scalable interfaces containing default implementations. Toward the concluding chapters, you’ll discover recipes on functional programming concepts, such as lambdas, monads, functors, and Kotlin scoping functions, which will help you tackle a range of real-life coding problems. By the end of this book, you'll be equipped with the expertise you need to address a range of challenges that Kotlin developers face by implementing easy-to-follow solutions.
Table of Contents (11 chapters)

Mocking dependencies with the Mockito Kotlin library

Often when writing unit test cases for complex classes, we face the problem of instantiating a great number of properties that the class we want to test depends on. Although this problem could be solved with dependency injection, it is faster, more efficient, and more desirable to mock a behavior of a specific object without instantiating it at all. In this recipe, we are going to explore how to use the Mockito Kotlin library to mock dependencies when writing a unit test for a simple registration form that contains an internal dependency whose behavior we are going to mock.

Getting ready

We are going to use the JUnit library, which provides the core framework for running...