formatter for rubocop: output relative path with emacs style

rubocop_emacs_formatter_expansion.rb

module RuboCop
  module Formatter
    class EmacsStyleFormatter < BaseFormatter
      def file_finished_with_relative_path(file, offenses)
        path = Pathname(file).relative_path_from(Pathname.pwd).to_s

        file_finished_without_relative_path(path, offenses)
      end

      alias file_finished_without_relative_path file_finished
      alias file_finished file_finished_with_relative_path
    end
  end
end