code: function addBOMToFile (file) {
      if (!file.match(/\.(js|htm|html|css|json)$/i)) {
          return;
      }
  
      // skip if this is a folder
      if (!fs.lstatSync(file).isFile()) {
          return;
      }
  
      var content = fs.readFileSync(file);
      if (content[0] !== 0xEF && content[1] !== 0xBE && content[2] !== 0xBB) {
          fs.writeFileSync(file, '\ufeff' + content);
      }
  }
docs: Adds BOM signature at the beginning of file, specified by absolute
  path. Ignores directories and non-js, -html or -css files.
  
  @param {String} file Absolute path to file to add BOM to