Code Coverage Metrics in Buildkite?

Hi there,

I was wondering if there is any interest in seeing code coverage metrics for every pull request? This is something that we do at work for all of our Rails projects, so I figured it could be valuable to future and current Rails contributors.

I recently wrote this article: What Are the Code Coverage Metrics for Ruby on Rails? - | Rails Upgrade Service in which I calculated code coverage metrics for all of the components in Rails. (my article still needs some work.)

I could submit a pull request but I’m not sure if that is a good idea: Comparing rails:master...fastruby:simplecov · rails/rails · GitHub (this needs some polishing, I admit)

Seeing code coverage metrics could help in increasing code coverage in the project, encourage new contributors to submit pull requests with new tests, improve tests, find classes that need better coverage, and guide new contributors in adding tests to their code.

Also, we would be able to set up code coverage trends in Code Climate:

The down side is that it will increase the total run time for running the test suite.

Is there a good reason why Ruby on Rails is not calculating code coverage at the moment?

Thanks in advance for your feedback!

Best, Ernesto