Powershell: How to use Invoke-Command and dot sourcing at the same time?

Question

I have the following scripts:

.
|-- invoke-command.ps1
|-- no-dot-sourcing.ps1
`-- with-dot-sourcing.ps1

Here are their contents:

invoke-command.ps1

$scriptPath = Split-Path -Parent $PSCommandPath
Invoke-Command `
    -ComputerName "myserver" `
    -Credential "myusername" `
    -FilePath "$scriptPath\with-dot-sourcing.ps1"

no-dot-sourcing.ps1

function getMessage() {
    return "This script just shows a message - executed on $env:COMPUTERNAME"
}

Write-Host (getMessage)

with-dot-sourcing.ps1

$scriptPath = Split-Path -Parent $PSCommandPath
. "$scriptPath\no-dot-sourcing.ps1"

Problem

If I call Invoke-Command with -FilePath "$scriptPath\no-dot-sourcing.ps1" everything works perfectly well. I need to call it with-dot-sourcing.ps1 and the reason for this is that I have some common functions that I use in other scripts. So, one solution would be to include everything in just one huge script and then everything will work, but I don't find this to be a good solution.

If I run the invoke-command.ps1 script I get the following error:

Cannot bind argument to parameter 'Path' because it is an empty string.
    + CategoryInfo          : InvalidData: (:) [Split-Path], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorEmptyStringNotAllowed,Microsoft.PowerShell.Commands.SplitPathCommand
    + PSComputerName        : myserver

The term '\no-dot-sourcing.ps1' 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.
    + CategoryInfo          : ObjectNotFound: (\no-dot-sourcing.ps1:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException
    + PSComputerName        : myserver 

In case it matters: I use Windows 7 Ultimate SP1 on local computer and on the server I have Windows Server 2012 Datacenter.

Is there any way I can use dot sourcing and still be able to use Invoke-Command?

Answer 1

It's possible to use PowerShell sessions to accomplish it in the following way:

invoke-command.ps1

$scriptPath = Split-Path -Parent $PSCommandPath
$credential = Get-Credential

$remoteSession = New-PSSession -ComputerName "myserver" -Credential $credential

Invoke-Command -Session $remoteSession -FilePath "$scriptPath\no-dot-sourcing.ps1"
Invoke-Command -Session $remoteSession -FilePath "$scriptPath\with-dot-sourcing.ps1"

Answer 2

You can't use the dot-sourcing, because execution won't happen until it gets to the target machine, and then the dot-source reference will be local to that machine, and those scripts don't exist there. You need to include everything in the script.

That being said, you can build the script from local script files before you send it:

@'
Write-Output 'This is test.ps1'
'@ | sc test.ps1


$sb = [scriptblock]::create(@"
Write-Output "Checking test."
. {$(get-content test.ps1)}
"@)

invoke-command -ScriptBlock $sb

Checking test.
This is test.ps1