fs.access() not reporting error on Windows

[dougwit]

• Version: 9.6.1
• Platform: Windows 7 Professional x64
• Subsystem: fs

fs.access() returns no error when given a file/directory with no priveleges.

Code example:

'use strict'

const fs = require('fs')

fs.access('./restricted', fs.constants.R_OK || fs.constants.W_OK, err => {
  if (err) {
    console.log(err)
  } else {
    console.log('no access() error')
  }
})

fs.stat('./restricted', (err, stat) => {
  if (err) {
    console.log(err)
  } else {
    console.log('no stat() error')
  }
})

Output:

no access() error
{ Error: EPERM: operation not permitted
  errno: -4048,
  code: 'EPERM',
  syscall: 'stat',
  path: 'C:\\Workspaces\\restricted' }

[joyeecheung]

See #7700 , fs.access does not check ACL on Windows

[joyeecheung]

Setting a doc label because the documentation seems to be misleading:

fs.constants.R_OK - path can be read by the calling process.
fs.constants.W_OK - path can be written by the calling process.

[joyeecheung]

Also cc @bnoordhuis is that a wont-fix on Windows?

[bzoz]

This can be probably fixed in libuv, there is AccessCheck function in WinAPI that seems to do just that. For now lets just document this.

[bnoordhuis]

This can be probably fixed in libuv

I don't know if we should (but I also don't know if we shouldn't); we don't check ACLs on other platforms.

[dougwit]

Not all platforms use ACLs as their native permissions mechanism. Ignoring ACLs makes fs.access() essentially useless on Windows, and the function fails to do what it says it does:

Tests a user's permissions for the file or directory specified by path.

[bnoordhuis]

Determining whether an ACL applies is a Hard Problem on many platforms. Doing it on one platform but not others makes it inconsistent. You're welcome to open a pull request but I expect other collaborators will raise the same concern.

[dlong500]

I agree that this behavior makes fs.access useless on Windows except for simply checking that a file/folder exists at all.

As far as consistency is concerned, things are already inconsistent in behavior if fs.access works as designed on one platform but not on another, so I don't see anything wrong with implementing platform-specific internals to create more consistency in the API behavior.

[suchakraborty]

Actually in 10.15.3 LTS, it does NOTHING, not even file existence check. I dont even have a D drive on my machine, and C:\dev does exist.

PS C:\Users\sc> node -e "const fs = require('fs'); fs.access('D:\\afsd', (err) => {console.log(``${err} is the error.``)})"
 is the error.
PS C:\Users\sc> node -e "const fs = require('fs'); fs.access('C:\\dev', (err) => {console.log(``${err} is the error.``)})"
 is the error.

[stelladraco27]

I am having this exact issue. I am reading a directory's contents into an array, and getting the stat for each item. I attempted to use fs.access to filter out un-readable folders/files but it would not throw an error. I ended up using the error fs.stat provides to do my filtering. A janky solution, don't like it.