expand_patterns

# File railties/lib/rails/test_unit/test_requirer.rb, line 16
        def expand_patterns(patterns)
          patterns.map do |arg|
            arg = arg.gsub(/(:\d+)+?$/, '')
            if Dir.exist?(arg)
              "#{arg}/**/*_test.rb"
            else
              arg
            end
          end
        end