The target of this formatter is Phabricator compliant code coverage report. More details at: secure.phabricator.com/book/phabricator/article/arcanist_coverage/
gem install simplecov-phabricator
Add the gem to the Gemfile preferably in the group test:
gem 'simplecov', require: false gem 'simplecov-phabricator', require: false
Enable formatter:
require 'simplecov' require 'simplecov-phabricator' SimpleCov.formatter = SimpleCov::Formatter::PhabricatorFormatter