Private/Tools/Expand-AvmToolArchive.ps1

function Expand-AvmToolArchive {
    <#
    .SYNOPSIS
        Unpack a downloaded tool archive into a target directory.

    .DESCRIPTION
        Handles the three archive kinds supported by tools.lock.psd1:
            - 'zip' -> Expand-Archive
            - 'tar.gz' -> tar -xzf (requires GNU/BSD tar on PATH)
            - 'raw' -> Copy-Item (single-binary archives)

        The target directory must already exist. On 'raw' the file is copied
        to '<TargetDir>/<EntrypointBasename>' so callers can stat predictable
        paths without round-tripping the archive's own filename.
    #>

    [CmdletBinding()]
    [OutputType([void])]
    param(
        [Parameter(Mandatory)] [string] $ArchivePath,
        [Parameter(Mandatory)] [ValidateSet('zip', 'tar.gz', 'raw')] [string] $Archive,
        [Parameter(Mandatory)] [string] $TargetDir,
        [Parameter(Mandatory)] [string] $EntrypointBasename
    )

    Set-StrictMode -Version 3.0
    $ErrorActionPreference = 'Stop'

    if (-not (Test-Path -LiteralPath $TargetDir)) {
        throw [System.IO.DirectoryNotFoundException]::new(
            "Expand-AvmToolArchive: TargetDir does not exist: $TargetDir")
    }

    switch ($Archive) {
        'zip' {
            Expand-Archive -LiteralPath $ArchivePath -DestinationPath $TargetDir -Force
        }
        'tar.gz' {
            $tar = Get-Command -Name 'tar' -ErrorAction SilentlyContinue
            if (-not $tar) {
                throw [System.IO.FileNotFoundException]::new(
                    "Expand-AvmToolArchive: 'tar' is not on PATH; required for tar.gz archives.")
            }
            & $tar.Source -xzf $ArchivePath -C $TargetDir
            if ($LASTEXITCODE -ne 0) {
                throw [System.IO.IOException]::new(
                    "tar -xzf failed with exit code $LASTEXITCODE for $ArchivePath.")
            }
        }
        'raw' {
            $finalName = if ($IsWindows) { "$EntrypointBasename.exe" } else { $EntrypointBasename }
            $dest = Join-Path $TargetDir $finalName
            Copy-Item -LiteralPath $ArchivePath -Destination $dest -Force
            if (-not $IsWindows) {
                & chmod 755 $dest 2>$null
            }
        }
    }
}