Lame implementation of Guard in PowerShell

guard-rake.ps1

param(
  [string] $path = (Split-Path $MyInvocation.MyCommand.Definition),
  [string] $task = 'default'
)

Start-Guard -Path $path -Action { rake $task }

New-FileSystemWatcher.ps1

function New-FileSystemWatcher {

  param(
    [ValidateNotNullOrEmpty()]
    [string] $Path = (Split-Path $MyInvocation.MyCommand.Definition)
  )

  $watcher = New-Object System.IO.FileSystemWatcher
  $watcher.Path = $path
  $watcher.IncludeSubdirectories = $true
  $watcher
}

Start-Guard.ps1

function Start-Guard {
  
  param(
    [ValidateNotNullOrEmpty()]
    [string] $Path = (Split-Path $MyInvocation.MyCommand.Definition),
    
    [Parameter(Mandatory = $true)]
    [ValidateNotNullOrEmpty()]
    [scriptblock] $Action
  )
  
  $watcher = New-FileSystemWatcher $path
  $timeout = 3000
  
  while($true) {
    $result = $watcher.WaitForChanged('All', $timeout)
  
    if($result.TimedOut) {
      continue
    }
  
    & $action
  
    Start-Sleep -Milliseconds $timeout
  }
}

ps> .\guard-rake.ps1 -Path "$pwd\source" -Task 'build'