fs.promises.realpath errors with long paths (fs.realpath.native does not error)

[sapphi-red]

Version

v20.9.0, v20.10.0

Platform

Microsoft Windows NT 10.0.22621.0 x64

Subsystem

fs

What steps will reproduce the bug?

Save the following script in a path that has more than 10 characters (e.g. C:\\abcdefghi).
Then, run it.

import { resolve } from 'node:path'
import { realpath, writeFile } from 'node:fs/promises'
import { realpath as realpathCallback, realpathSync } from 'node:fs'

const p = `./test_${'a'.repeat(240)}.txt`

await writeFile(p, '')

console.log('length: ', resolve(p).length)

try {
  await realpath(p)
} catch (e) {
  console.log('error with fs.promises.realpath', e)
}

try {
  await new Promise((res, rej) => {
    realpathCallback(p, (err, resolved) => {
      if (err) {
        rej(err)
        return
      }
      res(resolved)
    })
  })
} catch (e) {
  console.log('error with fs.realpath', e)
}

try {
  await new Promise((res, rej) => {
    realpathCallback.native(p, (err, resolved) => {
      if (err) {
        rej(err)
        return
      }
      res(resolved)
    })
  })
} catch (e) {
  console.log('error with fs.realpath.native', e)
}

try {
  realpathSync(p)
} catch (e) {
  console.log('error with fs.realpathSync', e)
}

try {
  realpathSync.native(p)
} catch (e) {
  console.log('error with fs.realpathSync.native', e)
}

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior? Why is that the expected behavior?

No error happens.

What do you see instead?

The following error happens:

error with fs.promises.realpath [Error: ENOENT: no such file or directory, realpath './test_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.txt']

Additional information

Maybe related to #50753, but running (Get-Item -Path "Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem").GetValue("LongPathsEnabled") (in both normal mode and admin mode) returns 0 on my machine.

Also #39721 might be related.

[sapphi-red]

node/lib/fs.js

Lines 2931 to 2938 in 23031d9

	realpath.native = (path, options, callback) => {
	callback = makeCallback(callback || options);
	options = getOptions(options);
	path = getValidatedPath(path);
	const req = new FSReqCallback();
	req.oncomplete = callback;
	binding.realpath(pathModule.toNamespacedPath(path), options.encoding, req);
	};

node/lib/internal/fs/promises.js

Lines 1159 to 1167 in 23031d9

	async function realpath(path, options) {
	options = getOptions(options);
	path = getValidatedPath(path);
	return await PromisePrototypeThen(
	binding.realpath(path, options.encoding, kUsePromises),
	undefined,
	handleErrorFromBinding,
	);
	}

It seems pathModule.toNamespacedPath is missing for fs.promises, will make a PR.