Convers a Sitecore Powershell Extension item to a file on disk.

Convert-ScriptItemToFile.ps1

function Convert-ScriptItemToFile {
      <#
    .SYNOPSIS
        Convers a SPE item to a file on disk. 
        
    .NOTES
        Autor: Robert Senktas (@RobsonAutomator)
    #>

    [CmdletBinding(SupportsShouldProcess = $True)]
    param (   
        [parameter(ValueFromPipelineByPropertyName, ValueFromPipeline)]
        [Sitecore.Data.Items.Item]
        $Item,

        # The root path for SPE module scripts. This will be replaced with $FileRoot parameter.
        [string]
        $ScriptRoot = "/sitecore/system/Modules/PowerShell/Script Library",
        
        # Folder on disk where items will be saved as files
        [string]
        $FileRoot
    )

    process {
        # build a filesystem path
        $scriptPath = $Item.Paths.Path  -replace $ScriptRoot,$FileRoot -replace "/","\" 
        $scriptFolder = Split-Path $scriptPath -Parent

        $whatifMessage = "Save script to a file $scriptPath.ps1"
        If ($PSCmdlet.ShouldProcess($Item.ID, $whatifMessage)) {
            # create a folder structure
            mkdir $scriptFolder -Force | Out-Null
    
            # save script to file
            $encoding = New-Object System.Text.UTF8Encoding
            [System.IO.File]::WriteAllText("$scriptPath.ps1", $Item."Script", $encoding)
        }
    }
}