param([Parameter(Mandatory=$true)][string]$OutFile)
$lines = New-Object System.Collections.Generic.List[string]
function L($s) { $lines.Add($s) }
L ("PSVersion: " + $PSVersionTable.PSVersion + "   PSEdition: " + $PSVersionTable.PSEdition)
L ""
L "### (1) can the host be asked whether it wants VT? ###"
$p = $Host.UI | Get-Member -Name SupportsVirtualTerminal -MemberType Property -ErrorAction SilentlyContinue
L ("  [bool](`$Host.UI | Get-Member -Name SupportsVirtualTerminal)   = " + [bool]$p + "   (a REAL property, not a stub)")
$rw = $Host.UI.RawUI | Get-Member -Name SupportsVirtualTerminal -MemberType Property -ErrorAction SilentlyContinue
L ("  [bool](`$Host.UI.RawUI | Get-Member -Name SupportsVirtualTerminal) = " + [bool]$rw + "  (does NOT exist on RawUI)")
L ("  value of `$Host.UI.SupportsVirtualTerminal = " + [string]$Host.UI.SupportsVirtualTerminal)
L ("  property TypeName: " + $(if ($p) { $p.Definition } else { 'n/a' }))
L ""
L "### (2) is it WRITABLE? (the documented way to turn VT off: `$Host.UI.SupportsVirtualTerminal = `$false) ###"
$before = [string]$Host.UI.SupportsVirtualTerminal
try { $Host.UI.SupportsVirtualTerminal = $false; $setOk = $true } catch { $setOk = $false; L ("  setter THREW: " + $_.Exception.Message) }
if ($setOk) { L ("  set `$false  -> value is now [" + [string]$Host.UI.SupportsVirtualTerminal + "] (before [$before])") }
try { $Host.UI.SupportsVirtualTerminal = $true } catch {}
L ("  restored  -> value is now [" + [string]$Host.UI.SupportsVirtualTerminal + "]")
L ""
L "### (3) WIDTH / HEIGHT REPORTING WHEN THERE IS NO CONSOLE (scheduled-task-like) ###"
L ("  [Console]::IsOutputRedirected = " + [Console]::IsOutputRedirected)
try { L ("  [Console]::WindowWidth        = " + [Console]::WindowWidth) } catch { L ("  [Console]::WindowWidth        THREW: " + $_.Exception.Message) }
try { L ("  [Console]::BufferWidth        = " + [Console]::BufferWidth) } catch { L ("  [Console]::BufferWidth        THREW: " + $_.Exception.Message) }
try { L ("  `$Host.UI.RawUI.WindowSize    = " + $Host.UI.RawUI.WindowSize.Width + 'x' + $Host.UI.RawUI.WindowSize.Height + "   <-- WRONG/hidden console, does not throw") } catch { L ("  RawUI.WindowSize THREW: " + $_.Exception.Message) }
try { [Console]::SetCursorPosition(2, 2); L "  [Console]::SetCursorPosition    = OK" } catch { L ("  [Console]::SetCursorPosition    THREW: " + $_.Exception.Message) }
try { $c = New-Object System.Management.Automation.Host.Coordinates 2, 2; $Host.UI.RawUI.CursorPosition = $c; L ("  `$Host.UI.RawUI.CursorPosition = OK -> " + $Host.UI.RawUI.CursorPosition.X + ',' + $Host.UI.RawUI.CursorPosition.Y) } catch { L ("  RawUI.CursorPosition setter     THREW: " + $_.Exception.Message) }
L ""
L "### (4) EXIT CODE PATH (the two entry scripts end with exit <code>) ###"
L ("  `$LASTEXITCODE before = " + $LASTEXITCODE)
L "  (run: powershell -File x.ps1 ; echo %ERRORLEVEL%)"
L "### (5) [Console]::ReadKey / RawUI.ReadKey availability ###"
try { L ("  `$Host.UI.RawUI.KeyAvailable = " + $Host.UI.RawUI.KeyAvailable) } catch { L ("  RawUI.KeyAvailable THREW: " + $_.Exception.Message) }
try { L ("  [Console]::KeyAvailable      = " + [Console]::KeyAvailable) } catch { L ("  [Console]::KeyAvailable THREW: " + $_.Exception.Message) }
L ("  RawUI members: " + (($Host.UI.RawUI | Get-Member -MemberType Property,Method | Select-Object -ExpandProperty Name) -join ','))
[System.IO.File]::WriteAllLines($OutFile, $lines, (New-Object System.Text.UTF8Encoding($false)))
Write-Host ("[vt-probe {0}] wrote {1}" -f $PSVersionTable.PSVersion, $OutFile) -ForegroundColor Yellow