code: function getParseType (file) {
    let ext = path.extname(file)
  
    for (let type in FILE_TYPE_MAP) {
      let exts = FILE_TYPE_MAP[type]
  
      if (exts.indexOf(ext) >= 0) {
        return type
      }
    }
  }
docs: get parser type of file
  @param  {String} file
  @return {String}