Undoubtedly, the trait of testing has been at the forefront of the software engineering discipline. The deep and decisive presence of software in every kind of tangible object in our daily environments these days in order to have plenty of smart, connected, and digitized assets is widely accepted. Also, with an increased focus on distributed and synchronized software, the complexity of the software design, development, testing and debugging, deployment, and delivery are continuously on the rise. Various means and mechanisms are unearthed to simplify and streamline the much-needed automation of software building and the authentication of software reliability, resiliency, and sustainability. Docker is emerging as an extremely flexible tool to test a wide variety of software applications. In this chapter, we will discuss how to effectively leverage the noteworthy advancements of Docker for software testing and its unique advantages in accelerating and augmenting testing automation.

The following topics are discussed in this chapter:

• A brief overview of TDD
• Testing your code inside Docker
• Integrating the Docker testing process into Jenkins

Docker containers are currently being leveraged to create development and testing environments that are the exact replicas of the production environment. Containers require less overhead when compared with virtual machines, which have been the primary environments for development, staging, and deployment environments. Let's start with an overview of Test-driven Development (TDD) of the next generation software and how Docker-inspired containerization becomes handy in simplifying the TDD process.