module SimpleCov::ResultMerger

def merge_coverage(*results)
  return [[""], nil] if results.empty?
  return results.first if results.size == 1
  results.reduce do |(memo_command, memo_coverage), (command, coverage)|
    # timestamp is dropped here, which is intentional (we merge it, it gets a new time stamp as of now)
    merged_coverage = Combine.combine(Combine::ResultsCombiner, memo_coverage, coverage)
    merged_command = memo_command + command
    [merged_command, merged_coverage]
  end
end