Preface

Test-Driven Development (TDD) goes hand-in-hand with Agile practices, which is gradually becoming the undisputed standard process or delivering quality software on time. The TDD process originated from the need to better understand and refine the requirements for a system.

Scala has gradually, despite all apprehensions, made a niche for itself as the language of choice for delivering modern versatile systems and microservices. It is slowly and steadily replacing the conventional object-oriented models with more robust and immutable functional constructs. The popularity of Scala emanates from the fact that it provides a bridge for developers to make a transition from the object-oriented to the functional world.

Scala, like all other languages, can allow developers to get so engrossed in its intricacies and magic that the real purpose of the application can easily get lost in over-engineering. Therefore, TDD is required to keep the application code tightly tied to the requirements.