class SimpleCov::Formatter::LcovFormatter

def format_file(file)
  "SF:#{file.filename}\n".tap do |content|
    file.lines.reject(&:never?).reject(&:skipped?)
      .each do |line|
      content << "DA:#{line.number},#{line.coverage}\n"
    end
    content << "end_of_record\n"
  end
end