Handling fs.constants.O_DIRECTORY flag

[corwin-of-amber]

In Node.js, it is possible to open a directory with fs.open or fs.openSync, specifying read access and optionally the flag fs.constants.O_DIRECTORY.
The effect of the flag is only that Node.js will raise ENOTDIR if the file is not a directory.

> fd = fs.openSync("/tmp/a", fs.constants.O_RDONLY)
29
> fd = fs.openSync("/tmp/a", fs.constants.O_RDONLY | fs.constants.O_DIRECTORY)
Thrown:
Error: ENOTDIR: not a directory, open '/tmp/a'
    at Object.openSync (fs.js:440:3) {
  errno: -20,
  syscall: 'open',
  code: 'ENOTDIR',
  path: '/tmp/a'
}
> fs.openSync('/', fs.constants.O_RDONLY)
30
> fs.openSync('/', fs.constants.O_RDONLY | fs.constants.O_DIRECTORY)
31

In memfs, the flag is ignored when opening a file and rejected when attempting to open a directory (openLink thinks the requested access is not read-only).

> m.openSync('/', fs.constants.O_RDONLY)
openLink true 0 0
2147483646
> m.openSync('/', fs.constants.O_RDONLY | fs.constants.O_DIRECTORY)
Thrown:
Error: EISDIR: illegal operation on a directory, open
    at createError (node_modules/memfs/lib/volume.js:131:17)
    at Volume.openLink (node_modules/memfs/lib/volume.js:774:19)
    at Volume.openFile (node_modules/memfs/lib/volume.js:806:25)
    at Volume.openBase (node_modules/memfs/lib/volume.js:811:25)
    at Volume.openSync (/Users/corwin/var/workspace/Web.OS.Shell/node_modules/memfs/lib/volume.js:822:21) {
  code: 'EISDIR'
}

[corwin-of-amber]

The issue has been patched in this fork, although not completely. I will try to make a PR based on that.

[streamich]

@corwin-of-amber thanks!

[corwin-of-amber]

Extremely welcome 😄

[streamich]

🎉 This issue has been resolved in version 3.0.4 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀