You really want to make sure that unit tests are run every time someone commits.
Three simple scripts. The first should be run by all engineers that join the team. It should do most of the installs for environment dependencies. The second should be a pre-commit script. This script should run your tests and anything else that you want to have happen. The third script should be an update script. It should be a simple script that gets run by your second script. It should automatically update your pre-commit script.
When the TuesdayCompany started I was working with a pretty junior engineer. In fact, he hadn’t graduated from college yet. Luckily, he was incredibly smart and motivated. Unfortunately, he had never written unit tests. This resulted in much of the early codebase having no tests. While this worked for a while, it was less than ideal. Eventually the company began to get some traction and I was able to come on board full time. By then the code was in the classic “there are unit tests, but not enough of them” state. So to counteract this state and to make sure that we could continue to grow the unit test coverage, I devised this system. I’m sure lots of other people have done similar things. I take no credit for being the first. My inspiration came from the trusting trust paper. This is one of my favorite papers of all time. If you haven’t given it a read, it is well worth the time.