Test in PowerShell code if a folder is a junction point?

Question

How can I test in PowerShell code if a folder is a junction point?

Answer 1

Since at least PowerShell v5.0, there is better support for links (or as MS calls them: Reparse Points)

improved Item cmdlets - LinkType property

Linked article is under WMF 5.0 category, which might mean that the method was available since PS v5.0.
These features were included in standard Get-Item, Get-ChildItem, so there are no additional steps required. It can be used on any current PS.

LinkType is a String property on an Object, returned by Get-Item and Get-ChildItem,
it can have one of the following four values: '', 'Junction', 'SymbolicLink', 'HardLink'.

To answer OP's question, you can check if a folder is a junction point using:

if ((Get-Item -Path $Target -Force).LinkType -eq "Junction") { }

To check if a file/folder is a "ReparsePoint", of any kind (Junction, SymbolicLink or HardLink):

if ((Get-Item -Path $Target -Force).LinkType) { }

LinkType value on ordinary file/folder is an empty String, which when used as if condition in PS resolves to False

Get-ChildItem can be used to list all Junction folders:

(Get-ChildItem -Path $Target -Force) | Where-Object { $_.LinkType -eq "Junction" }

Note that value 'SymbolicLink' is the same for both file or folder, so to list only Symbolic links to folders:

(Get-ChildItem -Path $Target -Directory -Force) | Where-Object { $_.LinkType -eq "SymbolicLink" }

Cmdlet Get-ChildItem (alias: dir, ls, gci) now shows ReparsePoint attribute, as l in Mode column, without any extension. But it will not show 'HardLink' and shows l for both Junction and SymbolicLink:

> Get-ChildItem -Path $Target -Force


    Directory: C:\Users


Mode                LastWriteTime         Length Name                          
----                -------------         ------ ----                          
d--hsl       2018-04-12     01:45                All Users                     
d-rh--       2018-05-09     06:12                Default                       
d--hsl       2018-04-12     01:45                Default User                  
d-----       2018-06-24     03:05                Papo                          
d-r---       2018-07-27     07:12                Public

• LinkType does not work on folders with special permissions inside \Users and \Users\, even though Get-ChildItem as seen above does work and shows l on them.
• Remove-Item has issues. It can't remove Junction, and if Forced, will remove original contents with it. This is said to be fixed in future version PS v6

---

Using these improved, or today's standard Cmdlets, has some advantages over previous methods, described in older answers here.

• It does differentiate between Junction and Symbolic Link
  If OP wanted to test if folder is a Junction, checking by Attribute property would result in false positive for folder Symbolic Link.

• detects Hard Link.

• LinkType is [String] as opposed to Attributes property, which is [FileAttributes] type and needs .ToString() or a use of -band