Book Image

Reactive Programming in Kotlin

By : Rivu Chakraborty
Book Image

Reactive Programming in Kotlin

By: Rivu Chakraborty

Overview of this book

In today's app-driven era, when programs are asynchronous, and responsiveness is so vital, reactive programming can help you write code that's more reliable, easier to scale, and better-performing. Reactive programming is revolutionary. With this practical book, Kotlin developers will first learn how to view problems in the reactive way, and then build programs that leverage the best features of this exciting new programming paradigm. You will begin with the general concepts of Reactive programming and then gradually move on to working with asynchronous data streams. You will dive into advanced techniques such as manipulating time in data-flow, customizing operators and provider and how to use the concurrency model to control asynchronicity of code and process event handlers effectively. You will then be introduced to functional reactive programming and will learn to apply FRP in practical use cases in Kotlin. This book will also take you one step forward by introducing you to Spring 5 and Spring Boot 2 using Kotlin. By the end of the book, you will be able to build real-world applications with reactive user interfaces as well as you'll learn to implement reactive programming paradigms in Android.
Table of Contents (20 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Dedication
Preface

Introduction to unit testing and its importance


While testing is absolute necessary in application development, many novice developers get away with a few basic questions regarding testing. They are:

  • What is unit testing? and why is it a developer's job?
  • Why is unit testing so important?
  • And, do we need to write unit tests for each section of our programs?

We will start this chapter by answering these basic questions. If you would like to rather start with testing using RxKotlin directly, you can skip the first few sections in this chapter and start from Testing tools in RxKotlin. Though I would encourage you to read the chapter throughout, even if you have previous experience in testing with Kotlin.

Let's start by defining unit testing. Unit testing is a level of software testing where  the individual smallest testable components of a software (aka application), called units are tested. The purpose is to validate that each unit of the software performs as it was supposed to.

Unit tests can be...