Coverage testing tool for The Go Programming Language

go get github.com/axw/gocov/gocov

There are currently three gocov commands: test, report and annotate.

Running gocov test <package> will, for the specified package, instrument all imported packages not part of the standard library, and run "go test". Upon completion, coverage data will be emitted in the form of a JSON document.

By default only the specified package will be instrumented and consequently have coverage information provided for. There are several flags that can change this behaviour.

By running gocov test -deps <package> you direct gocov to recursively instrument package dependencies, in which case coverage information will be provided for all dependencies as well. The coverage information provided is relative only to the tests run in the originally specified package.

e.g. If you run gocov test -deps net/http, then you will see coverage information not just for net/http, but also its dependencies; the output tells you what code in the dependencies is exercised when the net/http tests are run.

If you specify -deps but wish to exclude a specific package from instrumentation, you can pass an additional -exclude flag, e.g. gocov test -deps -exclude comma,separated,packages. If you wish to exclude all packages in GOROOT, then you can use the shortcut -exclude-goroot flag instead.

Running gocov report <coverage.json> will generate a textual report from the coverage data output by gocov test. It is assumed that the source code has not changed in between.

Output from gocov test is logged to stdout so users with POSIX compatible terminals can direct the output to gocov report to view a summary of the test coverage, for example: -

gocov test mypackage | gocov report

Running gocov annotate <coverage.json> <package[.receiver].function> will generate a source listing of the specified function, annotating it with coverage information, such as which lines have been missed.

GoCovGUI: A simple GUI wrapper for the gocov coverage analysis tool.

gocov-html: A simple helper tool for generating HTML output from gocov.

goveralls: Go integration for Coveralls.io continuous code coverage tracking system.