Improving code coverage visibility
In https://bugs.ruby-lang.org/issues/10189 the simplecov gem was added to generate coverage reports for specs.
However, the docs in
coverage/README are very sparse and appear to be out of date. At least, I haven't been able to generate a coverage report locally.
Even if I can do so, and that process is made easier, it still would be nice to have a definitive source of the current coverage level. This mirrors using Travis and AppVeyor as the definitive sources for the current status of test runs.
I think that especially on a large project with many contributors, code coverage is a valid part of a CI pipeline. Discouraging patches that drop coverage is beneficial in the same way as discouraging ones that break tests.
Personally, I've used coveralls.io for this purpose because they integrate nicely with Travis and follow a similar licensing model. However, any similar solution would be just as great.
Also, I would eventually like to see unified coverage reports for Ruby's C code as well its Ruby code, but I understand that may not be very feasible currently.