file

const fs = require('fs')
//비구조화 방식으로 필요한것만 받음
const {promisify} = require('util') 

//콜백함수로 사용
const read = promisify(fs.readFile)
const write = promisify(fs.writeFile)

const writeAndRead = async (data = '') => {
	try{
		await write('text.txt',data)
		return (await read('text.txt'))
	}catch(e){
		console.error(e)
	}
}
writeAndread('some contents')