Commands: Get-ScoopPackageVersions, Invoke-ScoopPackageCommand, Install-ScoopPackage

ScoopExtensions.ps1

function Get-ScoopRoot {
    $scoopdir = & {
        $env:SCOOP, (scoop config 'rootPath'), "$env:USERPROFILE\scoop" | Where-Object { -not [String]::IsNullOrEmpty($_) } | Select-Object -First 1
    } 6>$null
    $scoopdir
}

function Get-ScoopPackageVersions {
    param (
        [Parameter(Position = 1, Mandatory = $true)]
        $Name,
        [switch]
        $IncludeDescription
    )

    $info = $(scoop info $Name) 6>$null
    if (-not $?) {
        Write-Error "Could not find manifest for '$Name'." -ErrorAction Stop
    }

    $scoopdir = Get-ScoopRoot
    $bucket = $info.Bucket
    Push-Location -Path "$scoopdir\buckets\$bucket\bucket"

    $rawLogs = $(git grep '\"version\": \?\"' $(git rev-list --all -- "$Name.json") -- "$Name.json")
    $logs = $rawLogs | ForEach-Object {
        ($_ -match '^(?<hash>[\w\d]+):.+?\"version\": ?\"(?<version>.+?)\"') | Out-Null
        $obj = [PSCustomObject]@{
            CommitHash  = $Matches.hash
            Version     = $Matches.version
            Description = ""
        }
        if ($IncludeDescription.IsPresent) {
            $obj.Description = $(git log --format=%B -n 1 $Matches.hash)[0]
        }

        $obj
    }

    Pop-Location
    $logs
}

function Invoke-ScoopPackageCommand {
    param (
        [ValidateSet(
            "cat",
            "depends",
            "home",
            "info",
            "install",
            "virustotal"
        )]
        [Parameter(Position = 1, Mandatory = $true)]
        $Command,
        [Parameter(Position = 2, Mandatory = $true)]
        $PackageName,
        $CommandArgs,
        $CommitHash,
        $Version
    )

    $info = $(scoop info $PackageName) 6>$null
    if (-not $?) {
        Write-Error "Could not find manifest for '$PackageName'." -ErrorAction Stop
    }

    $scoopdir = Get-ScoopRoot
    $bucket = $info.Bucket
    Push-Location -Path "$scoopdir\buckets\$bucket\bucket"

    if ($null -ne $CommitHash) {
        git restore --source=$CommitHash "$PackageName.json"
        if ($?) {
            scoop $Command $CommandArgs $PackageName
        }
    }
    elseif ($null -ne $Version) {
        $commits = Get-ScoopPackageVersions -Name $PackageName
        $filteredCommits = $commits | Where-Object Version -EQ $Version
        if ($null -ne $filteredCommits) {
            git restore --source=$($filteredCommits[0].CommitHash) "$PackageName.json"
            if ($?) {
                scoop $Command $CommandArgs $PackageName
            }
        }
        else {
            Write-Error "Could not find manifest for $PackageName@$Version"
        }
    }
    else {
        scoop $Command $CommandArgs $PackageName
    }

    git restore "$PackageName.json"

    Pop-Location
}

function Install-ScoopPackage {
    param (
        [Parameter(Position = 1, Mandatory = $true)]
        $Name,
        $CommandArgs,
        $CommitHash,
        $Version
    )

    Invoke-ScoopPackageCommand -Command install -CommandArgs $CommandArgs -PackageName $Name -Version $Version -CommitHash $CommitHash
}

Bravo! These powershell functions are a great addition for somebody who knows his way around git repos which Scoop buckets indeed are. At the moment you could argue that Scoop has a naive (or a bit too straightforward) way of using git for app manifest versioning. One could easily imagine a system where past versions of app manifests would be always available alongside the current one and not just checkpointed by git in a HEAD version. However, as long as Scoop's manifest framework remains they way it is now, the approach taken by this script is golden -- within the scalability limits git greps etc. of course.

Btw. I made the following aliases for myself:

Set-Alias -Name scoopx -Value Invoke-ScoopPackageCommand
Set-Alias -Name scoopx-install -Value Install-ScoopPackage
Set-Alias -Name scoopx-versions Get-ScoopPackageVersions

You probably didn't want to be so opinionated, so just an idea. :)

@jkniiv Thanks!