One-page PowerShell Git Prompt. Alternative to posh-git.

Git-Prompt.ps1

# Add to PowerShell $PROFILE

function Get-GitPrompt {
    $inGitRepo = [bool](git rev-parse --is-inside-work-tree 2>$null)
    if (-not $inGitRepo) {
        return
    }
    
    $branch = git branch --show-current
    $status = git status --short --branch
    $statusLine = ([string[]]$status)[0]
    if ($statusLine -match '\.\.\.(?<remote>\S+)( \[(ahead (?<ahead>\d+))?((, )?behind (?<behind>\d+))?\])?') {
        $remoteStatus = ' '
        if ($Matches['ahead']) {
            $remoteStatus += "↑$($Matches['ahead'])"
        }
        if ($Matches['behind']) {
            $remoteStatus += "↓$($Matches['behind'])"
        }
        if ([string]::IsNullOrWhiteSpace($remoteStatus)) {
             $remoteStatus += '≡'
        }
    } else {
        $remoteStatus = ''
    }

    $stagedChanges = ($status | Select-String '^M' | Measure-Object).Count
    $unstagedChanges = ($status | Select-String '^ M' | Measure-Object).Count
    $stagedAdds = ($status | Select-String '^A' | Measure-Object).Count
    $unstagedAdds = ($status | Select-String '^\?\?' | Measure-Object).Count
    $stagedDeletes = ($status | Select-String '^D' | Measure-Object).Count
    $unstagedDeletes = ($status | Select-String '^ D' | Measure-Object).Count
    
    $e=$([char]0x1b)
    if ($remoteStatus.Contains('↑') -and $remoteStatus.Contains('↓')) {
        $branch = "$e[93m$branch"   # Yellow
    } elseif ($remoteStatus.Contains('↑')) {
        $branch = "$e[92m$branch"   # Green
    } elseif ($remoteStatus.Contains('↓')) {
        $branch = "$e[91m$branch"   # Red
    } else {
        $branch = "$e[96m$branch"   # Blue
    }
    
    if ($stagedChanges -ne '0' -or $stagedAdds -ne '0' -or $stagedDeletes -ne '0') {
        $staged = " $e[32m+$stagedAdds ~$stagedChanges -$stagedDeletes"
    }
    if ($unstagedChanges -ne '0' -or $unstagedAdds -ne '0' -or $unstagedDeletes -ne '0') {
        $unstaged = " $e[31m+$unstagedAdds ~$unstagedChanges -$unstagedDeletes"
    }
    if ($staged -and $unstaged) {
        $separator = " $e93m|"
    }
    
    $prompt = "$e[93m[$e0m$branch$remoteStatus$staged$separator$unstaged$e[93m]$e[0m"
    if ($host.UI.SupportsVirtualTerminal) {
        return $prompt
    } else {
        return $prompt -replace '\x1b\[\d+m', ''
    }
}

function prompt {
    $gitPrompt = Get-GitPrompt
    if ($gitPrompt) {
        $Host.UI.RawUI.WindowTitle = "$(Split-Path -Leaf $PWD) $gitPrompt" -replace '\x1b\[\d+m', ''
        "PS ${PWD} $gitPrompt> "
    } else {
        $Host.UI.RawUI.WindowTitle = $PWD
        "PS ${PWD}> "
    }
}

# Command completion
Register-ArgumentCompleter -Native -CommandName git -ScriptBlock {
    param([string]$wordToComplete, [string]$commandAst, [int]$cursorPosition)
    
    $command = $commandAst.Split(' ', [StringSplitOptions]::RemoveEmptyEntries)
    $options = switch -Regex ($command[1]) {
        'branch|checkout|merge' { git branch --list "${wordToComplete}*" | Where-Object { -not $_.StartsWith('*') } }
        default { (git --list-cmds=main) -match "^${wordToComplete}" }
    }
    $options | ForEach-Object {
        [System.Management.Automation.CompletionResult]::new($_.Trim(), $_.Trim(), 'ParameterValue', $_.Trim())
    }
}