fs API promise

> fs API promise file
``js
const fs = require('fs-promise-polyfill')
fs.readFile(path).then(data => {
console.log(data)
})
`

> Even a synchronous API, it does not need to use try-catch
`js
// return the data or instanceof Error
const data = fs.readFileSync(path, 'utf-8')
console.log(data instanceof Error)
console.log(data)
// or
// return the data or null
const data = fs.readFileSyncNull(path, 'utf-8')
console.log(data)
// or
fs.readFileSyncP(path, 'utf-8').then(data => {
console.log(data)
})
``

API List

- for native
+ [ ] constants
+ [ ] Stats
+ [ ] F_OK
+ [ ] R_OK
+ [ ] W_OK
+ [ ] X_OK
+ [x] access
+ [x] accessSync
+ [x] exists
+ [x] existsSync
+ [x] readFile
+ [x] readFileSync
+ [x] close
+ [x] closeSync
+ [x] open
+ [x] openSync
+ [x] read
+ [x] readSync
+ [x] write
+ [x] writeSync
+ [x] rename
+ [x] renameSync
+ [x] truncate
+ [x] truncateSync
+ [x] ftruncate
+ [x] ftruncateSync
+ [x] rmdir
+ [x] rmdirSync
+ [x] fdatasync
+ [x] fdatasyncSync
+ [x] fsync
+ [x] fsyncSync
+ [x] mkdir
+ [x] mkdirSync
+ [x] readdir
+ [x] readdirSync
+ [x] fstat
+ [x] lstat
+ [x] stat
+ [x] fstatSync
+ [x] lstatSync
+ [x] statSync
+ [x] readlink
+ [x] readlinkSync
+ [x] symlink
+ [x] symlinkSync
+ [x] link
+ [x] linkSync
+ [x] unlink
+ [x] unlinkSync
+ [x] fchmod
+ [x] fchmodSync
+ [x] chmod
+ [x] chmodSync
+ [x] fchown
+ [x] fchownSync
+ [x] chown
+ [x] chownSync
+ [ ] _toUnixTimestamp
+ [x] utimes
+ [x] utimesSync
+ [x] futimes
+ [x] futimesSync
+ [x] writeFile
+ [x] writeFileSync
+ [x] appendFile
+ [x] appendFileSync
+ [x] watch
+ [x] watchFile
+ [x] unwatchFile
+ [x] realpathSync
+ [x] realpath
+ [x] mkdtemp
+ [x] mkdtempSync
+ [x] copyFile
+ [x] copyFileSync
+ [ ] createReadStream
+ [ ] ReadStream
+ [ ] FileReadStream
+ [ ] createWriteStream
+ [ ] WriteStream
+ [ ] FileWriteStream
- extensions
+ [x] exsits
+ [x] exsitsSync
+ [x] mkdirSync