Powershell: Remove-Module doesn't care about casing, but Import-Module does care

[alexandair]

PowerShell Core on Linux.

Steps to reproduce

# this works
Remove-Module psreadline
# this fails
Import-Module psreadline
# you need to run
Import-Module PSReadLine 

Expected behavior

Consistent behavior for both cmdlets.

Actual behavior

# this works
Remove-Module psreadline
# this fails
Import-Module psreadline

Environment data

PS /home/aleksandar> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      6.0.0-alpha
PSEdition                      Core
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   3.0.0.0
GitCommitId                    v6.0.0-alpha.18
CLRVersion
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

[iSazonov]

@alexandair Thanks for your report!

I believe if on Unix we allow import different modules modulename and Modulename we should be case-sensitive in Remove-Module and Get-Module too?

[rkeithhill]

Is it a good idea to allow case-sensitive module names considering that Windows will not support such module names as its file system is case-insensitive? Seems like PowerShell should treat modules as case-insensitive. I don't see any value in allowing posh-git, Posh-Git and Posh-GIT to be different modules. I think that would just lead to confusion. IMO all of the module-related commands should be case-insensitive. And if on Linux someone has both mymodule and MyModule dirs. and is trying to import Mymodule, PowerShell should warn the user about the conflict.

[iSazonov]

If we consider the module names as case-insensitive, then should we do the same in relation to the names of scripts and other PowerShell files?

[rkeithhill]

I don't think so. Script filename casing should following the OS's casing rules. That said, the PowerShell Gallery should consider warning (or rejecting) when publishing scripts that would stomp a different script with the same name on a case-insensitive file system. Either that or use some other means of disambiguation (author name, pub-date, version, etc).

[iSazonov]

I expect that this will amaze users that .psm1 is case-insensitive and .ps1 case-sensitive.

[rkeithhill]

Loading a module by path doesn't have to follow the same rules as loading a module by name. Considering module "names" are backed by file system names, I'll admit this gets messy. But given that command names in PowerShell are case-insensitive, it seems like the right way to go.

[joeyaiello]

I believe this is an application of the question raised in #706. Ideally, we should address this all up.

[SteveL-MSFT]

Dupe of https://github.com/PowerShell/PowerShell/issues/1621