Drive letter case is different from the process.cwd

[sheremet-va]

Describe the bug

This is a very niche issue that affects Vitest and anyone using the ModuleRunner alongside native imports.

This issue appears only when running Vite in CMD.EXE and only if process.cwd() has a lowercase drive letter (c:/ instead of C:/).

The incorrect values are present in every path returned from the this.resolve also uses a different drive letter casing (note: rollup returns the same case as in process.cwd())

Reproduction

https://stackblitz.com/edit/node-86cw3m?file=vite.config.js,index.js,basic.js,test.js,package-lock.json

Steps to reproduce

# make sure the drive letter is lowercase
cd c:\Users\me\test
npm install
npm run dev

All imports are transformed with /@fs/ prefix instead of being relative to the localhost. (and they also use the wrong casing)

import * as test from '/@fs/C:/Users/me/test/basic.js'

The value returned from the server.pluginContainer.resolveId also changes the casing.

The casing is kept as is only if resolve.preserveSymlink is enabled. This is because the normalization happens during the realpathSync call:

vite/packages/vite/src/node/fsUtils.ts

Line 423 in 0ab20a3

function getRealPath(resolved: string, preserveSymlinks?: boolean): string {

vite/packages/vite/src/node/utils.ts

Line 654 in 0ab20a3

function windowsSafeRealPathSync(path: string): string {

System Info

System:
    OS: Windows 11 10.0.22631
    CPU: (24) x64 12th Gen Intel(R) Core(TM) i9-12900KF
    Memory: 51.11 GB / 63.85 GB
  Binaries:
    Node: 20.14.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 3.5.0 - C:\Program Files\nodejs\yarn.CMD
    npm: 10.7.0 - C:\Program Files\nodejs\npm.CMD
    pnpm: 9.12.2 - C:\Program Files\nodejs\pnpm.CMD
  Browsers:
    Edge: Chromium (127.0.2651.74)
    Internet Explorer: 11.0.22621.3527

Used Package Manager

npm

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.