Create default code template for PowerShell ISE

ISECodeTemplate.ps1

function Edit-ISETemplate{
    $ISETemplatePath = "$([Environment]::GetFolderPath('MyDocuments'))\WindowsPowerShell\ISETemplate.ps1"
    if (!Test-Path){
        New-Item $ISETemplatePath -ItemType File
    }
    psedit "$ISETemplatePath"
}

Register-ObjectEvent $psise.CurrentPowerShellTab.Files CollectionChanged -Action {
    # files collection
	$ISETemplate = "$([Environment]::GetFolderPath('MyDocuments'))\WindowsPowerShell\ISETemplate.ps1"
	if (Test-Path $ISETemplate){
        try{
		    $sender | 
                where {$_.IsUntitled -and $_.Editor.Text.Length -eq 0 } | 
		        foreach { 
                    $_.Editor.Text = Get-Content $ISETemplate -Raw
            } 
        }
	    catch {
            write-error $_
        }
    }
} -SourceIdentifier CodeTemplate

Hi. You have little mistake in line 3. You forgotten about variable $ISETemplatePath. That will be better
if (-not (Test-Path -Path $ISETemplatePath)){