Node cannot handle extended windows paths

Why this is a good first issue

Windows path handling issue requiring filesystem changes

AI Summary

Node.js fails to handle extended Windows paths (prefixed with \\?\) when executing scripts. The issue appears related to filesystem path resolution and may require changes to how Node processes Windows paths. The main challenge is ensuring compatibility with existing path handling while adding support for extended paths.

Issue Description

Version

v25.1.0

Platform

Microsoft Windows NT 10.0.26200.0 x64

Subsystem

fs

What steps will reproduce the bug?

Running node using an extended path like so: node \\?\C:\absolute\path\to\file.js

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

Any absolute path prefixed by \\?\

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

The script is executed; or if the script file does not exist an error stating the file could not be found.

What do you see instead?

node:fs:2710
    const out = binding.lstat(base, false, undefined, true /* throwIfNoEntry */);
                        ^

Error: EISDIR: illegal operation on a directory, lstat 'C:'
    at Object.realpathSync (node:fs:2710:25)
    at toRealPath (node:internal/modules/helpers:62:13)
    at Module._findPath (node:internal/modules/cjs/loader:774:22)
    at resolveMainPath (node:internal/modules/run_main:35:21)
    at Module.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:146:20)
    at node:internal/main/run_main_module:33:47 {
  errno: -4068,
  code: 'EISDIR',
  syscall: 'lstat',
  path: 'C:'
}

Additional information

This may have been introduced by https://github.com/nodejs/node/pull/55623

Microsoft provide documentation on the path prefixes and semantics here: https://learn.microsoft.com/en-gb/windows/win32/fileio/naming-a-file

GitHub Labels

fswindows