It used to be. Somewhere, squeezed between the end of development and release. But then things changed, because they had to. We’re testing product ideas, way before there’s one line of code. We’re testing the code as it’s being written, because we want to make sure it does what we Read more…
One of the things that unit tests are best for is checking error conditions. While we want wider coverage of full happy flows, error conditions are sometimes hard to simulate in a big system, and unit tests excel at minimal setup to make sure our code handles the problem correctly. We have Read more…
Kevlin Henney asked once: Why do cars have brakes? Imagine if cars didn’t have brakes, how fast would you go? You’ll be driving really slow to not hit anything. But by giving the capability to slow down, brakes actually give us the ability to go faster. TDD is like a Read more…
TDD is pretty simple right? Obey the red-green-refactor step-by-step and you’re on your way to glorious, non-legacy code. It’s really easy to explain. The rules are easy to follow. Why then so few people actually do it, and when they do, so few actually do it well? In my talk Read more…
Introducing TDD is a lot more psychological than you think. When we start introducing TDD we need to think about how people new will react. For example, the first question that people ask is: How am I going to write the test if I don’t know what the code does? Read more…
If the 2nd D in TDD is design, then we’re talking about emergent design. The tests drive the design, which emerges from thin air, and step by step reveals itself in all its glory. Emergent design has got to be superior to upfront design, right? Well, it depends. If we’re Read more…
Whenever we learn a new skill, and go deeper, it feels like we’re climbing a stairway to mastery. A few years ago, I described how people get into unit testing, and their journey along the path, as walking up a staircase. I’ve seen many people go through this. Our stairs Read more…
Unit testing is a set of skills, that rarely appears on a resume. When I saw a resume with unit testing on it, it rose up to the top of the interview queue. I understood the person who put it there understands what it means to the business. If the Read more…
This is last, final, and 10th entry in the ten commandments of unit tests attributes that started here. And you should read all of them. We usually talk about isolation in terms of mocking. Meaning, when we want to write unit tests, and the code has dependencies, we use mocking Read more…
