Powershell Function 'Watch-Job', see the Progress of the Jobs you are running, kill all when one is failed

Watch-Job.psm1

<#
.Synopsis
   Watch Powershell Job progress.
.DESCRIPTION
   This function allows you monitor the progress of the Powershell Jobs you just started,
   it wil show a progressbar and the remaining jobs that are still running.
   one of the key features is the ability to stop the other Jobs when 1 is failed.
.EXAMPLE
    Watch-Job -Job $Jobs
    Shows a progress bar indication how many jobs are completed/still running
.EXAMPLE
    Watch-Job -Job $Jobs -StopJobOnError
    Shows a progress bar indication how many jobs are completed/still running
    When a single Job is Failed all other jobs that are still Running wil be Stopped.
.EXAMPLE
    Watch-Job -Job $Jobs -RemoveJob
    Shows a progress bar indication how many jobs are completed/still running
    When a Jobs is finished (Failed, Stopped, Completed, ...) the Job including the data it contained will be removed.
.EXAMPLE
    Watch-Job -Job $Jobs -StopJobOnError -RemoveJob
    Shows a progress bar indication how many jobs are completed/still running   
    When a single Job is Failed all other jobs that are still Running wil be Stopped.
    When a Jobs is finished (Failed, Stopped, Completed, ...) the Job including the data it contained will be removed.
.NOTES
   Created by Sten Lootens at 5-7-2018.
   Please contact me at sten@ltns.nl
.LINK
    https://gist.github.com/SteloNLD/20a2404ac557fe27d58c472201beeca0
#>
Function Watch-Job {
    [CmdletBinding()]
    [OutputType([System.Management.Automation.Job[]])]
    Param(
        
        # Powershell Job(s) to Watch, 
        # normally the result of the Start/Get-Job command or -AsJob parameter. 
        [Parameter(
            Mandatory=$true,
            ValueFromPipeline=$true
        )]
        [Alias("Jobs")] 
        [ValidateNotNull()]
        [System.Management.Automation.Job[]]$Job,
        
        # When Multiple Jobs are provided in the $Job Parameter and a single Job fails
        # This wil wil stop the remaining Jobs that are still running.
        [Switch]$StopJobOnError,

        # This wil remove the Job when it is finished (Failed, Stopped, Completed, ...)
        [Switch]$RemoveJob
    )
    
    # Setup the ProgessBar
    if (-Not $JobStartCount) {        
        #Create variable for the current scope (function) that is also avaiable to any child scopes (functions).
        $VariableJobStartCount = @{
            Name = "JobStartCount"
            Option = "AllScope"
            Value = ($Job | Measure-Object | Select-Object -ExpandProperty Count)        
        }; New-Variable @VariableJobStartCount                
        Write-Progress -PercentComplete 0 -Activity "Watch-Job" -Status "$JobStartCount/$JobStartCount Jobs Left" #-CurrentOperation "Waiting for a Job to Finisch"
    }
       
    # Wait for a single job to finisch (Failed, Stopped, Completed, ...)
    $Job | Wait-Job -Any | ForEach-Object {

        if ($_.State -eq 'Failed') {
            # Show a warning about the current 'Failed' Job
            Write-Warning "Job $($_.Name) returned with state $($_.State)"
            
            # Stop all other Jobs.
            if ($StopJobOnError) { 
                Write-Warning "A Job has failed, forcibly stopping other Jobs"
                $Job | Stop-Job 
            }
        }

        Else {
            # Show information about the current Job
            Write-Verbose "Job $($_.Name) retuned with state $($_.State)"
        }

        # Remove the Current Job
        if ($RemoveJob) { $_ | Remove-Job}

        # Wait for further Jobs to complete        
        $RemainingJobs = $Job | Where-Object Id -ne $_.Id
        If ($RemainingJobs) {            
            Write-Progress -PercentComplete (100-($RemainingJobs.Count)/$JobStartCount*100) -Activity "Watch-Job" -Status "$($RemainingJobs.Count)/$JobStartCount Jobs Left"
            Watch-Job -Job $RemainingJobs -StopJobOnError:$StopJobOnError -RemoveJob:$RemoveJob | Out-Null
        }

        Else {
            Write-Progress -Activity "Watch-Job" -Completed
        }
    }
    Return $Job
}

Also see my post on Code Review: https://codereview.stackexchange.com/questions/197910/