code: function hasEscapeFirst (data, offset) {
      isBuffer = (!isQuiet && typeof data !== 'string')
      escaped = (this.prev.idx > 0)
  
      return escaped
        ? ( escapeOffset = offset - escLength, -1 )
        //HACK to bypass the trimLeft/trimRight properties
        : ( this.prev.prev.length = leftLength + 1, atok.offset--, 1 )
    }
docs: Make the rule fail if an escape char was found