The State of Test Coverage in Rails

One of the things that we look for when examining the health of a Rails application is the percentage of test coverage the app has, using a tool like simplecov. This should only test the code your team has written and not 3rd party libraries (one reason why it’s important to keep your 3rd party dependencies separate from the rest of your code). In the Rails Survey this year, we asked a new question about how many existing Rails applications the respondents work on have decent test coverage (above 80%).