Passing an object from one script to another - powershell

Question

I am having an issue passing an array member to another script. I have a VM build script that pulls from a CSV, I end up with a $VM object with .Name, .CPU, .RAM, .IP, etc. I want to pass that VM object to another script (inside the new server) which can then act on it, but am unable to do so. I have been testing the correct syntax just to pass a simple array, like below, but am still not successful:
CSV:
Name,NumCPU,MemoryGB,IPAddress
JLTest01,2,4,172.24.16.25
Script1:
Function TestMe {
[CmdLetBinding()]
Param (
[Parameter(Mandatory, Position=1)]
[array]$arr
)
$arr | Out-GridView
}
TestMe
Calling Script:
$aVMs = Import-Csv -Path "PathToCsv"
foreach($VM in $aVMs) {
$command = "<path>\TestMe.ps1 " + "-arr $($VM)"
Invoke-Expression $command
}
This produces an error, which seems to be on parsing the array. The error states:
The term 'JLTest01' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:48 + ... \Desktop\TestMe.ps1 -arr #{Name=JLTest01; NumCPU ...
Just trying to figure out what I am doing wrong exactly, and what I need to do to pass the object to the second script.

Answer 1

Don't use Invoke-Expression (which is rarely the right tool and should generally be avoided for security reasons):
The stringification of the custom objects output by Import-Csv performed by $($VM) does not preserve the original objects; it results in a hashtable-like representation that isn't suitable for programmatic processing and breaks the syntax of the command line you're passing to Invoke-Expression.
Instead, just invoke your script directly:
$aVMs = Import-Csv -Path "PathToCsv"
.\TestMe.ps1 -arr $aVMs
Note that I'm passing $aVMs as a whole to your script, given that your -arr parameter is array-typed.
If you'd rather process the objects one by one, stick with the foreach approach (but then you should declare the type of your $arr parameter as [pscustomobject] rather than [array]):
$aVMs = Import-Csv -Path "PathToCsv"
foreach ($VM in $aVMs) {
.\TestMe.ps1 -arr $VMs
}
Another option is to declare $arr as accepting pipeline input, add a process block to your script, and then pipe $aVMs to your script ($aVMs | .\TestMe.ps1).
Also, don't nest a function of the same name inside your .ps1 script that you call from within the script, especially not without passing the arguments through; scripts can directly declare parameters, just like functions:
[CmdLetBinding()]
Param (
[Parameter(Mandatory, Position=1)]
[array]$arr
)
$arr | Out-GridView