PS_Completers

1.1.3

completers/link_completer/link_completer.ps1

# link tab completion for PowerShell
# Static option completion for link.exe and link.

Set-StrictMode -Version 2.0

function Get-LinkCompletionOptions {
    @('--help', '--version')
}

function New-LinkCompletionResult {
    param(
        [string]$CompletionText,
        [string]$ResultType,
        [string]$ToolTip,
        [string]$ListItemText
    )

    if ([string]::IsNullOrWhiteSpace($ListItemText)) {
        $ListItemText = $CompletionText
    }

    if ([string]::IsNullOrWhiteSpace($ToolTip)) {
        $ToolTip = $CompletionText
    }

    [System.Management.Automation.CompletionResult]::new(
        $CompletionText,
        $ListItemText,
        $ResultType,
        $ToolTip
    )
}

function ConvertFrom-LinkTypedWord {
    # The value of a typed word. A word opened with a quote (ASCII or typographic) is read by
    # the PowerShell tokenizer, which drops the quotes and undoes that quote style's escapes.
    param([string]$Value)

    if ($Value -notmatch '^[''"\u2018-\u201E]') {
        return $Value
    }

    $tokens = $null
    $parseErrors = $null
    [void][System.Management.Automation.Language.Parser]::ParseInput($Value, [ref]$tokens, [ref]$parseErrors)
    $tokens[0].Value
}

function ConvertTo-LinkQuotedValue {
    # Renders a value as one PowerShell argument: bare when safe and no quote was typed,
    # otherwise in the quote the user typed (single by default). PowerShell reads ' and
    # U+2018-U+201B as single quotes and " and U+201C-U+201E as double quotes.
    param(
        [string]$Value,
        [string]$QuoteChar = ''
    )

    if ([string]::IsNullOrEmpty($Value)) {
        return $Value
    }

    if (-not $QuoteChar) {
        if ($Value -notmatch '[\s{}();,|&<>''"`$@#\u2018-\u201E]' -and $Value -notmatch '^[-\u2013-\u2015]') {
            return $Value
        }

        $QuoteChar = "'"
    }

    if ($QuoteChar -match '^[''\u2018-\u201B]$') {
        return $QuoteChar + ($Value -replace '([''\u2018-\u201B])', '$1$1') + $QuoteChar
    }

    $QuoteChar + ($Value -replace '([`"$\u201C-\u201E])', '`$1') + $QuoteChar
}

function Get-LinkCurrentToken {
    param(
        [System.Management.Automation.Language.CommandAst]$CommandAst,
        [int]$CursorPosition
    )

    # The parser keeps an unterminated quoted word as one element running to the cursor.
    foreach ($element in ($CommandAst.CommandElements | Select-Object -Skip 1)) {
        $extent = $element.Extent
        if ($extent.StartOffset -lt $CursorPosition -and $CursorPosition -le $extent.EndOffset) {
            return $extent.Text.Substring(0, $CursorPosition - $extent.StartOffset)
        }
    }

    ''
}

function Get-LinkPathCompletions {
    param([string]$InputPath)

    $cleanInput = ConvertFrom-LinkTypedWord -Value $InputPath
    $quoteChar = if ($InputPath -match '^[''"\u2018-\u201E]') { $InputPath.Substring(0, 1) } else { '' }

    # The typed directory part (up to the last separator, or a drive) is kept exactly as typed,
    # including a leading .\ or ./, so completing never deletes typed text.
    $null = $cleanInput -match '^(?<dir>.*[\\/]|[A-Za-z]:)?(?<leaf>.*)$'
    $typedDir = [string]$Matches['dir']
    $leaf = $Matches['leaf']
    $parent = if ($typedDir) { $typedDir } else { '.' }

    if (-not (Test-Path -LiteralPath $parent -PathType Container -ErrorAction Ignore)) {
        return @()
    }

    $items = @(Get-ChildItem -LiteralPath $parent -ErrorAction Ignore)
    $items = $items | Where-Object { $_.Name -like ([System.Management.Automation.WildcardPattern]::Escape($leaf) + '*') } | Sort-Object -Property Name

    foreach ($item in $items) {
        # A bare name starting with a dash would reach link as an option, so it gets the
        # current-directory prefix, as PowerShell's own file completion does.
        $pathText = if ($typedDir) {
            $typedDir + $item.Name
        } elseif ($item.Name -match '^[-\u2013-\u2015]') {
            '.' + [System.IO.Path]::DirectorySeparatorChar + $item.Name
        } else {
            $item.Name
        }

        if ($item.PSIsContainer -and -not $pathText.EndsWith([System.IO.Path]::DirectorySeparatorChar)) {
            $pathText += [System.IO.Path]::DirectorySeparatorChar
        }

        $quotedPath = ConvertTo-LinkQuotedValue -Value $pathText -QuoteChar $quoteChar
        if ($item.PSIsContainer) {
            New-LinkCompletionResult -CompletionText $quotedPath -ListItemText $pathText -ResultType 'ProviderContainer' -ToolTip $item.FullName
        } else {
            New-LinkCompletionResult -CompletionText $quotedPath -ListItemText $pathText -ResultType 'ProviderItem' -ToolTip $item.FullName
        }
    }
}

function Complete-Link {
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSReviewUnusedParameter', 'wordToComplete', Justification = 'The word is cut from the CommandAst element at the cursor; wordToComplete spans past the cursor and unescapes quotes.')]
    param(
        [string]$wordToComplete,
        [System.Management.Automation.Language.CommandAst]$commandAst,
        [int]$cursorPosition
    )

    $currentWord = Get-LinkCurrentToken -CommandAst $commandAst -CursorPosition $cursorPosition

    if ([string]::IsNullOrEmpty($currentWord)) {
        return Get-LinkPathCompletions -InputPath ''
    }

    if ($currentWord.StartsWith('-')) {
        return @(
            foreach ($option in Get-LinkCompletionOptions) {
                if ($option.StartsWith($currentWord, [System.StringComparison]::OrdinalIgnoreCase)) {
                    New-LinkCompletionResult -CompletionText $option -ListItemText $option -ResultType 'ParameterName' -ToolTip 'Option for link.'
                }
            }
        )
    }

    Get-LinkPathCompletions -InputPath $currentWord
}

Register-ArgumentCompleter -Native -CommandName 'link', 'link.exe' -ScriptBlock {
    param($wordToComplete, $commandAst, $cursorPosition)

    Complete-Link -wordToComplete $wordToComplete -commandAst $commandAst -cursorPosition $cursorPosition
}