Add to your Gemfile

gem 'codecov', :require => false, :group => :test

Add to the top of your tests/helper.rb file

require 'simplecov'
SimpleCov.start

require 'codecov'
SimpleCov.formatter = SimpleCov::Formatter::Codecov

In your CI Environment Variables (not needed for https://travis-ci.org/)

CODECOV_TOKEN=<your repo token>

Find you repo token on your repo page at codecov.io. Repo tokens are not required for public repos on Travis-Ci, CircleCI, or AppVeyor CI.

if ENV['CI'] == 'true'
  require 'codecov'
  SimpleCov.formatter = SimpleCov::Formatter::Codecov
end

Jenkins, Travis CI, Codeship, Circle CI, Semaphore, drone.io, AppVeyor, Wercker, Magnum, Shippable, and Gitlab CI. Otherwise fallbacks on git.

Copyright 2014 codecov