Node: Doc has mistake: The fs doesn't exist constants of property

[TonyPythoneer]

• Version: 4.26
• Platform: Linux tony-iMac 4.4.0-31-generic #50-Ubuntu SMP Wed Jul 13 00:07:12 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

---

• Subsystem:

The API doc describes the constants will return a object:
https://nodejs.org/api/fs.html#fs_fs_constants

But, in fact, fs doesn't exist constants of property.

> fs.constants
undefined

The fs shows on console as following:

> fs
{ Stats: [Function],
  F_OK: 0,
  R_OK: 4,
  W_OK: 2,
  X_OK: 1,
  access: [Function],
  accessSync: [Function],
  exists: [Function],
  existsSync: [Function],
  readFile: [Function],
  readFileSync: [Function],
  close: [Function],
  closeSync: [Function],
  open: [Function],
  openSync: [Function],
  read: [Function],
  readSync: [Function],
  write: [Function],
  writeSync: [Function],
  rename: [Function],
  renameSync: [Function],
  truncate: [Function],
  truncateSync: [Function],
  ftruncate: [Function],
  ftruncateSync: [Function],
  rmdir: [Function],
  rmdirSync: [Function],
  fdatasync: [Function],
  fdatasyncSync: [Function],
  fsync: [Function],
  fsyncSync: [Function],
  mkdir: [Function],
  mkdirSync: [Function],
  readdir: [Function],
  readdirSync: [Function],
  fstat: [Function],
  lstat: [Function],
  stat: [Function],
  fstatSync: [Function],
  lstatSync: [Function],
  statSync: [Function],
  readlink: [Function],
  readlinkSync: [Function],
  symlink: [Function],
  symlinkSync: [Function],
  link: [Function],
  linkSync: [Function],
  unlink: [Function],
  unlinkSync: [Function],
  fchmod: [Function],
  fchmodSync: [Function],
  chmod: [Function],
  chmodSync: [Function],
  fchown: [Function],
  fchownSync: [Function],
  chown: [Function],
  chownSync: [Function],
  _toUnixTimestamp: [Function: toUnixTimestamp],
  utimes: [Function],
  utimesSync: [Function],
  futimes: [Function],
  futimesSync: [Function],
  writeFile: [Function],
  writeFileSync: [Function],
  appendFile: [Function],
  appendFileSync: [Function],
  watch: [Function],
  watchFile: [Function],
  unwatchFile: [Function],
  realpathSync: [Function: realpathSync],
  realpath: [Function: realpath],
  createReadStream: [Function],
  ReadStream: 
   { [Function: ReadStream]
     super_: 
      { [Function: Readable]
        ReadableState: [Function: ReadableState],
        super_: [Object],
        _fromList: [Function: fromList] } },
  FileReadStream: 
   { [Function: ReadStream]
     super_: 
      { [Function: Readable]
        ReadableState: [Function: ReadableState],
        super_: [Object],
        _fromList: [Function: fromList] } },
  createWriteStream: [Function],
  WriteStream: 
   { [Function: WriteStream]
     super_: { [Function: Writable] WritableState: [Function: WritableState], super_: [Object] } },
  FileWriteStream: 
   { [Function: WriteStream]
     super_: { [Function: Writable] WritableState: [Function: WritableState], super_: [Object] } } }

I suggest it should mark the property has been deprecated. Otherwise, it will cause misunderstanding.

[MylesBorins]

@TonyPythoneer fs.constants is not defined in the v4.x documentation, which can be found here

Closing. Please feel free to ask any questions

edit: the docs you linked to are for v6.x

[TonyPythoneer]

@TheAlphaNerd Thank you for your notification.

[jgoux]

@TheAlphaNerd I just encountered the issue when I tried to access fs.constants.F_OK

I'm on node v6.1.0 and I can confirm that there isn't a fs.constants object exported.

Simple test :

node -e "const fs = require('fs'); console.log(process.versions.node); console.log(fs.constants);"

Output :

6.1.0
undefined

EDIT : Sorry, I just realized that this change wasn't in v6.1.0. https://nodejs.org/docs/v6.1.0/api/fs.html :D

[jokeyrhyme]

FYI:

• 6.2 has fs.constants === undefined
• 6.3 has fs.constants !== undefined

I use the following in my code for compatibility, e.g.

fs.accessSync(binPath, (fs.constants || fs).X_OK)

[anshulguleria]

@MylesBorins Should this needs to be added to documentation also as a __Note__? Because post 6.3 fs.constants exist but not pre. And api documentation here says Added in: v0.11.15

[MylesBorins]

Feel free to send a PR to master with what you think will help and we can discuss there

[matthiasg]

Why is this closed ? I just stumbled over this and https://nodejs.org/dist/latest-v6.x/docs/api/fs.html does not declare in which version fs.constants was added.

[gibfahn]

Reopening, this will be closed by https://github.com/nodejs/node/pull/12690 when it lands.