open3_with_timeout

def open3_with_timeout(cmd)
      #require 'pry'; binding.pry
      inp, out, err, wait_thr = Open3.popen3(cmd)
      inp.close

      did_timeout = false

      still_open = [out, err]  # Array that only contains the opened streams
      output_buffer = ''
      stderr_buffer = ''
      output_lines = []
      stderr_lines = []

      while !still_open.empty?
        fhs = select(still_open, nil, nil, 300)
        output_lines.concat handle_io(still_open, fhs[0], out, output_buffer) unless fhs.nil?
        stderr_lines.concat handle_io(still_open, fhs[0], err, stderr_buffer) unless fhs.nil?
        if fhs.nil?
          did_timeout = true
          still_open.clear
        end
        # Could easily do something with the data here instead of holding it.
      end

      out.close
      err.close
      @logger.error 'Timeout waiting for output from cucumber' if did_timeout
      result = did_timeout ? nil : wait_thr.value
      return output_lines, stderr_lines, result
    end

    def handle_io(still_open, io_array, io, buffer)

      lines = []
      if io_array.include?(io)
        begin
          buffer << io.readpartial(4096)
          have_newline = buffer =~ /([^\n]+)\z/ ? $1 : nil

          buffer.scan(/.*\n/) do |line|
            lines << line.chomp
          end

          if have_newline
            buffer.replace(have_newline)
          else
            buffer.clear
          end
        rescue EOFError
          still_open.delete_if{|s| s == io}
        end
      end
      @logger.debug lines
      lines
    end