[BUG] npm run fails on Windows when project folder is case sensitive

[neilrackett]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

When case sensitivity is enabled, all scripts, e.g. npm run build, will fail with the error:

'module_name' is not recognized as an internal or external command

Where module_name is the name of the the module called by the script, e.g. webpack or cross-env

Expected Behavior

npm run should run scripts as normal, unaffected by the case sensitivity setting of the project folder (or its subfolders).

Steps To Reproduce

1. Open a command prompt or PowerShell window at the location of your project folder
2. Delete node_modules if it already exists
3. Make the project folder case sensitive using fsutil.exe file setCaseSensitiveInfo . enable
4. Run npm i
5. Try to run any script defined in your package.json file, e.g. npm run build
6. The script fails with an error similar to 'module_name' is not recognized as an internal or external command

As an alternative to steps 1-4, you could also recursively apply case sensitivity to the content of your project folder using this PowerShell command:

(Get-ChildItem -Recurse -Directory).FullName | ForEach-Object {fsutil.exe file setCaseSensitiveInfo $_ enable}

Environment

• OS: Windows 10 Pro (Microsoft Windows NT 10.0.19042.0 x64)
• Node: 14.17.0
• npm: 7.14.0

[neilrackett]

Possibly related to #1782?

[ruyadorno]

I can't reproduce this, I'm particularly stuck with the fsutil.exe file setCaseSensitiveInfo . enable with a Error: The request is not supported. in my windows system (Windows 10 Pro Version 20H2 Build 19042.928).

@npm/cli-team I do wonder whether this is a supported use case, it looks like support to case sensitivity is an opt-in feature in Windows 10.

@neilrackett it would also be appreciated if you can confirm you still have this error with the current version of the npm cli (npm@8.5.2 at the time of writing).