code: function parseFile (file, content) {
    let type = getParseType(file)
  
    debug('parse file: file = %s, parseType = %s', file, type)
  
    if (type in parser) {
      if (typeof content !== 'string') {
        content = fs.readFileSync(file, 'utf8')
      }
  
      return parser[type](content)
    }
  }
docs: parse file
  @param  {String} file - file path
  @param  {String} content - file content (optional)
  @return {Array} all deps