fs.access() not reporting error on Windows

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' }

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

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.

@bnoordhuis

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

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.

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.

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.

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.

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.

doc: document ACL limitation for fs.access on Windows

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.

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.

doc: document ACL limitation for fs.access on Windows

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fs.access() not reporting error on Windows #19192

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fs.access() not reporting error on Windows #19192

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joyeecheung commented on Mar 7, 2018

joyeecheung commented on Mar 7, 2018

joyeecheung commented on Mar 7, 2018

bzoz commented on Mar 8, 2018

bnoordhuis commented on Mar 8, 2018

dougwit commented on Mar 8, 2018

bnoordhuis commented on Mar 13, 2018

dlong500 commented on Jul 20, 2018

suchakraborty commented on Jun 10, 2020

stelladraco27 commented on Mar 1, 2022

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