Function to check whether the current user has write permissions to a directory or not

Get-CanWriteDirectory.ps1

#Requires -Version 6.2
function Get-CanWriteDirectory {
  [CmdletBinding()]
  Param(
    [Parameter(Mandatory, Position=0)]
    [ValidateScript(
      { Test-Path -PathType Container $_ },
      
      # Remove this property to make compatible with 5.1, 6.0, and 6.1
      ErrorMessage = "Could not find the path or it is not a directory: {0}"
    )]
    [string]$Path
  )
  
  # Make sure temp file doesn't already exist (we clean it up)
  $index = 0
  $tempFilePath = Join-Path $Path "$($MyInvocation.MyCommand -replace '-')Check$(( $index )).txt"
  while( Test-Path -PathType Leaf $tempFilePath ) {
    Write-Verbose "${tempFilePath} already exists. Incrementing index..."
    $tempFilePath = Join-Path $Path "$($MyInvocation.MyCommand -replace '-')Check$(( ++$index )).txt"
  }
  
  # Write temp file to see if we can
  $checkPermArgs = @{
    Path = $tempFilePath
    ErrorAction = 'Stop'
  }
  Write-Verbose "Writing file ${tempFilePath}"
  try {
    "$($MyInvocation.MyCommand) check $([DateTime]::Now)" | Out-File @checkPermArgs
  } catch {
    Write-Verbose "Error writing ""${tempFilePath}"": $($_.Exception.Message)"
    return $false
  }
  
  # Clean up our messy handiwork
  $removeItemArgs = @{
    Path = $tempFilePath
    ErrorAction = 'Stop'
    Force = $true
  }
  Write-Verbose "Removing file ${tempFilePath}"
  try {
    Remove-Item @removeItemArgs
  } catch {
    Write-Warning "Error removing temp file ""${tempFilePath}"": $($_.Exception.Message)"
  }
  
  $true
}