Powershell Invoke-Command not working in script - powershell

Question

I'm a beginner with Powershell and while working on a script I ran into a very weird issue.
I have the following code which works as expected:
$deploymentMachine = Read-Host "Please enter the name of the machine on which you want to deploy: "
$deploymentMachineUsername = Read-Host "Please enter the username: "
$deploymentMachinePassword = Read-Host "Please enter your password: " -AsSecureString
$credentials = New-Object System.Management.Automation.PSCredential ($deploymentMachineUsername, $deploymentMachinePassword)
$remoteSession = New-PSSession -ComputerName $deploymentMachine -Credential $credentials -ErrorAction Stop
and then I'm trying to check for the existence of a folder on the remote machine using:
if(Invoke-Command -Session $remoteSession { Test-Path "C:\Test" })
which throws the following error:
Cannot bind argument to parameter 'Path' because it is null.
If I run the same code line by line in the Powershell everything works as expected and get true or false depending on what folder I test.
Can somebody tell me why the code fails in the script, but works in the command prompt? What am I missing?
Thank you!

Answer 1

After some more digging I managed to find answer: I need to pass local variables used by the script block using the -ArgumentList (in my script the "C:\Test" was stored in a variable)
So the code looks like this now:
if(Invoke-Command -Session $remoteSession -ScriptBlock { Test-Path -Path $args[0] } -ArgumentList $tmp)
Thanks for the help!