class RuboCop::Cop::Layout::EndOfLine

def investigate(processed_source)
  last_token = processed_source.tokens.last
  last_line =
    last_token ? last_token.pos.line : processed_source.lines.length
  processed_source.raw_source.each_line.with_index do |line, index|
    break if index >= last_line
    msg = offense_message(line)
    next unless msg
    next if unimportant_missing_cr?(index, last_line, line)
    range =
      source_range(processed_source.buffer, index + 1, 0, line.length)
    add_offense(nil, range, msg)
    # Usually there will be carriage return characters on all or none
    # of the lines in a file, so we report only one offense.
    break
  end
end

def offense_message(line)
  effective_style = if style == :native
                      Platform.windows? ? :crlf : :lf
                    else
                      style
                    end
  case effective_style
  when :lf then MSG_DETECTED if line =~ /\r$/
  else MSG_MISSING if line !~ /\r$/
  end
end

def unimportant_missing_cr?(index, last_line, line)
  style == :crlf && index == last_line - 1 && line !~ /\n$/
end