Powershell startjob import-module call function with arguments - function

Question

So I am trying to start-job from a module I wrote.
Copy-Modules.psm1
function startcopy([string] $ShowToCopy) {
if (-not($ShowToCopy)) { return "No name provided. Doing nothing." }
} else { return "Name Provided $ShowToCopy" }
}
in the main script I am calling it as follows:
$Copyname = "test"
Start-Job -Name "copy1" -InitializationScript { Import-Module -Name .\Copy-Modules.psm1 } -ScriptBlock {startcopy} -ArgumentList $Copyname
However the arguments never seems to go through. No matter how I format or pass the argument with switch or without I always get the result No name provided. Doing nothing.

Answer 1

The simplest solution - assuming you need no other functions from your Copy-Modules.psm1 module - is to pass your function's body as Start-Job's -ScriptBlock argument:
Start-Job -Name "copy1" -ScriptBlock $function:startcopy -ArgumentList $Copyname
$function:startcopy uses namespace variable notation to get the startcopy's body as a script block.
Note:
This obviates the need to define your startcopy function in the scope of the background job (which is an independent session in a child process that knows nothing about the caller's state), which is what your -InitializationScript script block does.
The only limitation of this approach is that the script block won't be named, i.e. the original function name is lost, and $MyInvocation.MyCommand.Name inside the function returns the empty string.
As for what you tried:
It is the script block as a whole that receives the (invariably positional arguments passed to -ArgumentList, which you'll have to pass on explicitly to any commands called inside the script block, using the automatic $args variable:
$Copyname = "test"
# Note the use of $args[0]
Start-Job -Name "copy1" `
-InitializationScript { Import-Module -Name .\Copy-Modules.psm1 } `
-ScriptBlock { startcopy $args[0] } -ArgumentList $Copyname