If this is the first time you come across the Go coverage profile then do read my last post: Test coverage in Go, working with packages and sub-packages. It is an introduction to Go’s cover tool, how to generate the coverage profile and how to use it to aggregate the coverage from the sub-packages to the root package.

If you are already familiar with the cover tool and the coverage profile then let’s dive in and see a few cases that you need to be aware of if you are trying to aggregate the coverage from the sub-packages all the way to the root of your package.