Examples coverage

Thu, Sep 8, 2016

Go programming language provides many unique good features to write and maintain examples for your packages backed by the testing tools.

As an addition to the test coverage and test coverage report, go test also can provide coverage for testable examples.

Use the following commands in your package to use the -run flag to only the match the example tests and view the results in your browser.

$ go test -v -run=Example -coverprofile=c.out && go tool cover -html=c.out

Please note that the coverage is reported for Examples with an Output block. Examples without an “Output” block will not be tested and reported.

Here is what the coverage looks like for the strings package from the stdlib.

High example coverage is probably not a necessary signal and not all lines are supposed to be documented with an example but it might give you an idea whether you are missing out a significant non-obvious case that needs to be documented more comprehensively.