I sometimes teach test-driven development, or TDD, to developers who have never done it before. And at the beginning of those trainings, most of them struggle a lot with the first two steps of the “Red, Green, Refactor” cycle: How to write a failing test correctly and how to make this test pass correctly.

In this series of blog posts and videos, I want to focus on those first two steps: “Red” and “Green”. You can find all the parts of the series here: