code: function (files) {
      if (!_.isArray(files)) files = [files];
      return _.chain(files).map(fss.target).map(function (f) {
          if (!fss.directoryExists(f)) return f;
          return fss.allTargetFilePaths(f);
      }).flatten().uniq().reject(fss.isDotFile).map(pathSuffix).value();
  }
docs: /*
  Generate a list of all files that should be cached.