Repository navigation
Expand-Archive doesn't use -WhatIf parameter from calling function #6342
Description
When decorating a function with [CmdletBinding(SupportsShouldProcess=$true)], calling that function with -WhatIf will pass on the -WhatIf parameter to functions called within that also supports this. In the example below one can see this working for Move-Item, but not for Expand-Archive.
Steps to reproduce
function Demonstrate-Bug {
[CmdletBinding(SupportsShouldProcess=$true)]
param ()
# Does not rename file, but instead outputs the following:
# What if: Performing the operation "Move File" on target "Item: C:\Temp\Foo.zip Destination: C:\Temp\Bar.zip".
Move-Item -Path .\Foo.zip -Destination Bar.zip
# Would expect the following to not expand the archive, but instead only print a "What if" message similar to above.
Expand-Archive -Path .\Foo.zip
# If Expand-Arvhice is called explicitely with -WhatIf, I get the following output:
# What if: Performing the operation "Expand-Archive" on target "C:\Temp\Foo.zip".
}
Demonstrate-Bug -WhatIfExpected behavior
Expand-Archive isn't actually called, but instead a message explaining what would happen without -WhatIf is outputted.
Actual behavior
The Foo.zip archive gets expanded, even though Demonstrate-Bug is called with the -WhatIf parameter.
Environment data
> $PSVersionTable
Name Value
---- -----
PSVersion 5.1.16299.248
PSEdition Desktop
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 10.0.16299.248
CLRVersion 4.0.30319.42000
WSManStackVersion 3.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1Reacted by Michael Klement
Activity
mklement0 commentedon Mar 8, 2018
Good catch; it seems that
Expand-Archiveonly respects the global scope's$WhatIfPreferencevariable, not the local copy created implicitly inside the advanced function by passing-WhatIfto it.markekraus commentedon Mar 9, 2018
Hi Julian Klock (@juliank) ! can you file this issue at the https://github.com/PowerShell/Microsoft.PowerShell.Archive repo where the
Expand-Archivecode is maintained?The problem appears to be here:
https://github.com/PowerShell/Microsoft.PowerShell.Archive/blob/master/Microsoft.PowerShell.Archive/Microsoft.PowerShell.Archive.psm1#L336
Rather than using
$PSCmdlet.ShouldProcess()they are checking if the-WhatIfparameter is bound.. which means it would only support-WhatIfif directly supplied to the function.juliank commentedon Mar 9, 2018
I wasn't aware of that Mark Kraus (@markekraus), thank you.
But that doesn't seem like particularly active repo. I found an issue describing this very bug, which is a whole year old, and there isn't even a single comment. Much less any work done solving it...
mklement0 commentedon Apr 4, 2018
Actually, this is ultimately a duplicate of #4568, via #6556.
While there is code that checks
$psboundparameters.ContainsKey("WhatIf")explicitly, it is in addition to proper use ofif($pscmdlet.ShouldProcess($resolvedSourcePaths))in theprocessblock.In other words: the resolution isn't external: it's a fundamental PowerShell problem.