Book Image

Scala Test-Driven Development

By : Gaurav Sood
Book Image

Scala Test-Driven Development

By: Gaurav Sood

Overview of this book

Test-driven development (TDD) produces high-quality applications in less time than is possible with traditional methods. Due to the systematic nature of TDD, the application is tested in individual units as well as cumulatively, right from the design stage, to ensure optimum performance and reduced debugging costs. This step-by-step guide shows you how to use the principles of TDD and built-in Scala testing modules to write clean and fully tested Scala code and give your workflow the change it needs to let you create better applications than ever before. After an introduction to TDD, you will learn the basics of ScalaTest, one of the most flexible and most popular testing tools around for Scala, by building your first fully test-driven application. Building on from that you will learn about the ScalaTest API and how to refactor code to produce high-quality applications. We’ll teach you the concepts of BDD (Behavior-driven development) and you’ll see how to add functional tests to the existing suite of tests. You’ll be introduced to the concepts of Mocks and Stubs and will learn to increase test coverage using properties. With a concluding chapter on miscellaneous tools, this book will enable you to write better quality code that is easily maintainable and watch your apps change for the better.
Table of Contents (16 chapters)
Scala Test-Driven Development
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface

Test fixtures


Test fixture is a collection of classes, other libraries, and artifacts. These can be files, sockets, database connections, and so on, that are required for testing. Clean code principles dictate that we reuse these fixtures across tests and make them as abstract as possible. For example, if two tests require speaking to a database, then it would be obvious to reuse the same database connection code for both. It is important to try and avoid duplicating the fixture code across those tests. The more code duplication you have in your tests, the greater drag the tests will have on refactoring the actual.

These are the recommended techniques for reusing the code in ScalaTest:

  • Refactor using Scala

  • Override withFixture

  • Mixin a before-and-after trait

All of the preceding techniques are geared toward reducing code duplication by reducing dependencies between the tests. Eliminating a shared mutable state across tests will make your test code easier to reason with, and more amenable for...