Continuous Integration

A breaking continuous build system is a Stop-the-Presses event. We pause our work and gather around to fix the failing build together. I’ve frequently seen teams silence the alarms by turning on the “ignore” flag on the failing tests, or deleting the tests all together. Just to stop the “nuisance” notification emails. But that only hides problems, and can lead to broken software being deployed. Instead, it’s important for the team to be encouraged and given the ability to prioritize fixing the tests, rather than being pressured to quickly meet some other completion deadline. ...

Many teams accept it as normal, and “usual”, for the build to break now and again. Instead, foster a team culture where it’s considered an “unusual” thing. Before checking in code, the builder needs to run the unit tests and acceptance tests. If the build breaks, something unusual has happened, and we switch focus to fix it immediately. A simple visual trick that can help accelerate the discipline of keeping the build in good health: Create a visual calendar year grid diagram for the build, and mark a green dot for each day with no build failures and a red dot for each day with at least one build failure. ...