test_files_for (Autotest)

    # File lib/autotest.rb, line 497
      def test_files_for(filename)
        result = @test_mappings.find { |file_re, ignored| filename =~ file_re }

        p :test_file_for => [filename, result.first] if result and $DEBUG

        result = result.nil? ? [] : Array(result.last.call(filename, $~))

        output.puts "No tests matched #{filename}" if
          ($v or $TESTING) and result.empty?

        result.sort.uniq.select { |f| known_files[f] }
      end