We can generate a unit test coverage report in Golang using the following commands and tools which are included with the language.
To run unit tests with coverage collection use:
go test -covermode=count -coverpkg=./... -coverprofile cover.out -v ./...
The coverpkg parameter is needed for the code coverage to include packages and not just the top level files in the project directory.
Generate the visual coverage HTML files using:
go tool cover -html cover.out -o cover.html
If you are using a Makefile on macOS we can add a command to run all of this together in order and open the page in a browser:
test-coverage: go test -v ./... -covermode=count -coverpkg=./... -coverprofile coverage/coverage.out go tool cover -html coverage/coverage.out -o coverage/coverage.html open coverage/coverage.html
This will open the very nice coverage report HTML page in a browser.