Injection PowerShell Module

Injection.psm1

function doStuff {
    param(
        [string]
        $Item,

        [string]
        $Value = 'default'
    )

    $htDoStuff.($Item) = $Value
}

function Invoke-DoStuff {

    $stringFuncDoStuff = "${function:doStuff}"

    $htDoStuff = [System.Collections.Hashtable]::Synchronized((New-Object System.Collections.Hashtable)) #@{}

    $array = @('first', 'second')

    # ForEach-Object -Parallel
    $array | ForEach-Object -Parallel {
        $function:doStuff = $using:stringFuncDoStuff
        $htDoStuff = $using:htDoStuff

        doStuff -Item $PSItem
    }

    $htDoStuff
}

function Invoke-ModuleDoStuff {

    $stringFuncDoStuff = "${function:doStuff}"

    $array = @('first', 'second')

    # ForEach-Object -Parallel
    $array | ForEach-Object -Parallel {
        $function:doStuff = $using:stringFuncDoStuff
        $htDoStuff = $using:moduleHtDoStuff

        doStuff -Item $PSItem -Value $(Get-Date).Ticks
    }

    $moduleHtDoStuff
}

$moduleHtDoStuff = [System.Collections.Hashtable]::Synchronized((New-Object System.Collections.Hashtable)) #@{}

Export-ModuleMember -Function 'Invoke-DoStuff', 'Invoke-ModuleDoStuff'