CD Survey: How often do you run unit tests?

Running functional tests generally takes longer than running unit tests, so as expected, most people run unit tests more frequently than they run functional tests:

I was a bit surprised at how many people are running tests on every change, but that’s good news for JUnit Max, which shaves seconds off the delay waiting for feedback from tests. If those delays happen a hundred times a day, the cumulative effect of a tool like Max can be substantial. I’m not sure what to make of the teams that run unit tests daily or weekly. I’d like to talk to such a team to understand more about their process.

Unit testing wasn’t explicitly addressed by any of the presenters at the Continuous Deployment webinar, I think because unit testing is assumed when you’re deploying on a short cycle. I don’t recall who said it first, but the model I use is that the defects leaving any stage are proportional to the defects entering that stage. No matter how good your functional tests are, defects leaving the programmer’s desk need to be rare if the software is always going to be ready to deploy.