When we talk about software development, sooner or later someone starts a discussion about tests. In our world, tests are considered as something helpful and crucial to our work. However, sometimes we need to face with people who have a different opinion about it. Moreover, it’s hard to find a proper argument, especially for a person who pays you and who wants to utilize your time effectively.

How can you convince your boss to let you write tests? Should you even ask for permission?

JavaScript is one of the most versatile programming languages I know, however, I had a constant problem with the testing. Since I run into TDD, I was looking for something that allows me to build my solutions using this approach. When I had been creating a small project in React, I accidentally discovered Jest.

It surprised me because it hadn’t required any extra configuration. I thought that the configuration was built-in into the create-react-app tool. It turns out that zero-configuration is one of the philosophies behind this tool. I decided to try using it outside the React application. Since this moment, this is a standard tool for my unit tests for the JavaScript.

Let me show how easy work with Jest is.