Get-ChildItem -File and -Directory should be mutually exclusive

A minor problem, and perhaps rare in practice.

Get-ChildItem’s -File and -Directory switches limit the output to files only / directories only, respectively.

Therefore, it is pointless to allow both of them to be specified, given that no filesystem item can be both a file and a directory, and the output will always be nothing (null collection).

Steps to reproduce

Get-ChildItem -File -Directory

Expected behavior

An error indicating that incompatible switches were used, which would currently come in the form of parameter set cannot be resolved using the specified named parameters.

Actual behavior

The combination of these switches is allowed, and nothing is output.

Environment data

PowerShell Core v6.0.0-beta.8 on macOS 10.13
PowerShell Core v6.0.0-beta.8 on Ubuntu 16.04.3 LTS
PowerShell Core v6.0.0-beta.8 on Microsoft Windows 10 Pro (64-bit; v10.0.15063)
Windows PowerShell v5.1.15063.674 on Microsoft Windows 10 Pro (64-bit; v10.0.15063)

[SteveL-MSFT]

@HumanEquivalentUnit I think you hit upon another edge case. Since you provided a file to -Path, it can’t find any directories. Perhaps technically, it should have returned an error that it can’t get child items of a file regardless if -Directory or -File was provided.

[SteveL-MSFT]

Thinking about this, I can see how -File and -DIrectory could be interpreted as OR or AND. I don’t have a strong opinion either way on this one. However, if we change it so that the flag means “Include” (aka OR) where we now return everything compared to now where we return nothing (aka AND), that could break someone who was constructing the args programmatically.

Personally, I think this issue probably isn’t worth spending additional time on vs some other issues and would propose Won't Fix and leave it the way it is.