# File lib/autotest.rb, line 606
  def make_test_cmd files_to_test
    cmds = []
    full, partial = reorder(files_to_test).partition { |k,v| v.empty? }
    diff = self.unit_diff
    diff = " | #{diff}" if diff and diff !~ /^\|/

    unless full.empty? then
      classes = full.map {|k,v| k}.flatten.uniq
      classes.unshift testlib
      classes = classes.join " "
      cmds << "#{ruby_cmd} -e \"%w[#{classes}].each { |f| require f }\"#{diff}"
    end

    partial.each do |klass, methods|
      regexp = Regexp.union(*methods).source
      cmds << "#{ruby_cmd} #{klass} -n \"/^(#{regexp})$/\"#{diff}"
    end

    cmds.join "#{SEP} "
  end