I don’t know what to test until I write the code

A great frustration for TDD learners is knowing what to test without having written the production code beforehand. This is another criticism that has merit. In this case, once we understand the issue that developers face, we can see that the solution is a technique we can apply to our workflow, not a reframing of thinking.

Understanding the difficulty of starting with testing

To an extent, it’s natural to think about how we implement code. It’s how we learn, after all. We write System.out.println("Hello, World!"); instead of thinking up some structure to place around the famous line. Small programs and utilities work just fine when we write them as linear code, similar to a shopping list of instructions.

We begin to face difficulties as programs get larger. We need help organizing the code into understandable chunks. These chunks need to be easy to understand. We want them to be self-documenting...