Find the oldest line of extant ruby code in a git repository

oldest-line.rb

class OldestLineOfCode
  IGNORE_LINES = /.*?\)\s*(class |module |def |#|$)/

  def initialize
    @oldest = "2016-03-16"
    @oldest_file = nil
    @oldest_line = nil
  end

  def scan
    Dir.glob("**/*.rb").each(&method(:scan_file))

    puts "Oldest line of code is in #{@oldest_file} from #{@oldest} (#{@oldest_line})"
  end

  def scan_file(file)
    puts "Scanning #{file}"
    `git blame #{file}`.split("\n").each do |line|
      if (line =~ IGNORE_LINES).nil?
        last_modified = line.match(/\d{4}-\d{2}-\d{2}/)[0]
        if last_modified < @oldest
          @oldest = last_modified
          @oldest_file = file
          @oldest_line = line
        end
      end
    end
  end
end

OldestLineOfCode.new.scan

Oldest line of code is in app/controllers/admin/companies_controller.rb from 2006-11-10 (73687b83 app/controllers/companies_controller.rb (Graeme Mathison 2006-11-10 14:02:34 +0000 17) respond_to do |format|)