How can I pass-through parameters in a powershell function?

$args is not going to pass through arguments correctly. if you want the arguments to remain as separate arguments, you should use @args instead.

After seeing your comment, option 3 sounds like exactly what you want.

---

You have a few options:

1. Use $args (credit to hjpotter92's answer)

2. Explicitly define your additional parameters, then parse them all in your function to add them to your perl call.

3. Use a single parameter with the ValueFromRemainingArguments argument, e.g.

   function global:Test-Multi {
       Param(
           [string]$Suite,
           [parameter(ValueFromRemainingArguments = $true)]
           [string[]]$Passthrough
           )
       & perl -S "$Suite\runall.pl" -procs:$env:NUMBER_OF_PROCESSORS @Passthrough
   }
   

I'm not sure about what you wish to achieve, but the arguments passed to a function are accessible in the $args variable available inside the function.