code: function findConfigFiles (dir) {
    let result = []
  
    if (typeof dir !== 'string' || !fs.existsSync(dir)) {
      return result
    }
  
    const fileList = fs.readdirSync(dir)
  
    debug(`${dir} file list: %o`, fileList)
  
    result = linterConfigFile
      .filter(fileName => fileList.includes(fileName))
      .map(fileName => path.join(dir, fileName))
  
    debug('config file: %o', result)
  
    return result
  }
docs: 在指定目录下搜寻全部配置文件
  
  @param {string} dir 绝对路径
  @returns {Array<string>} 所有配置文件的路径