Set-DemoPrompt.ps1

function Set-DemoPrompt {
    <#
    .SYNOPSIS
    Creates a simple prompt with WT highlighting using a temporary module.
    minor trickery with setting an alias for prompt so we can easily restore old prompt on module removal.
    .NOTES
    it adds terminal prompt markings for WT Preview.
    see links below for more info
    .LINK
    https://learn.microsoft.com/en-us/windows/terminal/tutorials/shell-integration#powershell-pwshexe/
    prompt markings
    https://gist.github.com/mdgrs-mei/1599cb07ef5bc67125ebffba9c8f1e37
    progress indicator
    https://gist.github.com/mdgrs-mei/244496f094abc367d46a64d6c7f7dd7e
    .notes
    runs on powershell 5.1 and pwsh 7+
    #>
    if (Get-Module -Name DemoPrompt) {
        Remove-Module DemoPrompt -Force
    }
    New-Module -Name DemoPrompt -ScriptBlock {
        $script:LastCMD = $null
        $script:LastHistoryId = -1

        function Get-LastExitCode {
            if ($? -eq $True) {
                return 0
            }
            if ($error.count -gt 0) {
                $LastHistoryEntry = Get-History -Count 1
                $IsPowerShellError = $Error[0].InvocationInfo.HistoryId -eq $LastHistoryEntry.Id
            }
            if ($IsPowerShellError) {
                return 1
            }
            return $LastExitCode
        }
        function New-PromptBlock {
            [cmdletbinding()]
            param(
                [string[]]$Block,
                [object]$Color,
                [Switch]$Start,
                [Switch]$End,
                [int]$Padding = 1,
                [String]$Separator = [char]57520,
                [String]$StartIcon = [char]57526
            )
            $e = [char]27
            $reset = "$e[0m"
            $whitefg = "$e[38;2;255;255;255m"
            $minispace = [char]0x2009
            $redfg = "$e[31;1m"
            $sb = [System.Text.StringBuilder]::new()
            if ($Start) {
                [void]$sb.append($color.Foreground).
                Append($StartIcon).
                Append($color.background)
            }
            else {
                [void]$sb.append($color.background).
                append($Separator)
            }
            [void]$sb.append($whitefg)
            foreach ($entry in $Block) {
                [void]$sb.append($entry)
                if ($Padding -gt 0) {
                    [void]$sb.append(($minispace.ToString() * $Padding))
                }
            }
            [void]$sb.append($reset).
            Append($color.Foreground)
            if (-Not $End) {
                return $sb.ToString()
            }
            if ($lastCMD -ne 0) {
                [void]$sb.append($redfg)
            }
            [void]$sb.append($Separator)
            [void]$sb.append($reset)
            return $sb.ToString()
        }
        function RGBtoColor ($R, $G, $B) {
            return [PSCustomObject]@{
                Foreground = "$([char]27)[38;2;{0};{1};{2}m" -f $R, $G, $B
                Background = "$([char]27)[48;2;{0};{1};{2}m" -f $R, $G, $B
            }
        }
        Set-PSReadLineKeyHandler -Key Enter -BriefDescription 'MarkEndofcommandforWT' -ScriptBlock {
            try {
                $e = [char]27
                $startProgressIndicator = "$e]9;4;3;50$e\"
                $EndOfCommand = "$e]133;C`a"
                [Microsoft.PowerShell.PSConsoleReadLine]::AcceptLine()
                # progress indicator
                Write-Host $startProgressIndicator -NoNewline
                # command end, i think this needs to be after cause it marks start of output.
                Write-Host $EndOfCommand -NoNewline
            }
            finally {}
        }
        function Invoke-DemoPrompt {
            [cmdletbinding()]
            param()
            $script:LastCMD = Get-LastExitCode
            $LastHistoryEntry = Get-History -Count 1
            $e = [char]27
            if ($script:LastHistoryId -ne -1) {
                if ($LastHistoryEntry.Id -eq $script:LastHistoryId) {
                    $zero = "$e]133;D`a"
                    # no command input, so reset $LastCMD
                    $script:LastCMD = 0
                }
                else {
                    $zero = "$e]133;D;$LastCMD`a"
                }
            }
            $script:LastHistoryId = $LastHistoryEntry.Id
            $cwdir = $executionContext.SessionState.Path.CurrentLocation.Path
            $ht = @{
                errorIcon              = [char]9888
                HistoryIcon            = [Char]::ConvertFromUtf32(984589)
                pwshIcon               = [char]59011
                start                  = "$e]133;A`a"
                cwd                    = "$e]9;9;`"{0}`"`a" -f $cwdir
                endofprompt            = "$e]133;B`a"
                startProgressIndicator = "$e]9;4;3;50$e\"
                stopProgressIndicator  = "$e]9;4;0;50$e\"
            }
            if ($PSEdition -eq 'Core') {
                $versionstring = $PSVersionTable.PSVersion
            }
            else {
                $versionstring = $PSVersionTable.PSVersion.ToString(2)
            }
            $block1 = New-PromptBlock -Block $ht.pwshIcon, $versionstring -Color (RGBtoColor 58 58 58) -Start
            $block2 = New-PromptBlock -Block $ht.HistoryIcon, $MyInvocation.HistoryId, $ht.errorIcon, $global:error.count -Color (RGBtoColor 88 88 88)
            $block3 = New-PromptBlock -Block ($cwdir | Split-Path -Leaf) -Color (RGBtoColor 118 118 118) -End
            return $zero + $ht.stopProgressIndicator + $ht.start + $ht.cwd + $block1 + $block2 + $block3 + $ht.endofprompt
        }
        $OnRemove = {
            Remove-Item "alias:\prompt" -Force
            Set-PSReadLineKeyHandler -Chord 'Enter' -Function AcceptLine
        }
        $ExecutionContext.SessionState.Module.OnRemove += $OnRemove
        $registerEngineEventSplat = @{
            SourceIdentifier = ([System.Management.Automation.PsEngineEvent]::Exiting)
            Action           = $OnRemove
        }
        Set-Alias -Name prompt -Value Invoke-DemoPrompt -Force -Option AllScope -Scope Global
        Register-EngineEvent @registerEngineEventSplat
        Export-ModuleMember -Alias prompt -Function Invoke-DemoPrompt
    } | Import-Module -Global
}