fetch the version of a choco package and "increment" it by adding a prerelease tag

Get-NewPrereleasePackageVersion.ps1

param(
  [Parameter(Mandatory = $True)]
  [string] $id,

  [Parameter(Mandatory = $False)]
  [string ]$sources
)
$scriptName = $MyInvocation.MyCommand.Name
Write-Verbose "$scriptName / id: $id / sources: $sources"

if (-Not (Get-Command choco -ErrorAction SilentlyContinue)) {
  throw "you need choco to run this script!"
}

$pkgInfoString = if ($sources) {
  choco search --exact $id -r --pre --source="$sources"
}
else {
  choco search --exact $id -r --pre
}

$ecode = $LASTEXITCODE
Write-Verbose "choco.exe returned '$pkgInfoString' (err: $ecode)"
if ($ecode -ne 0) {
  throw "choco.exe exited with '$ecode'"
}
if (-Not $pkgInfoString) {
  Write-Verbose "pkg '$id' not found"
  return "0.0.1-pre1"
}

$ver = $pkgInfoString.Split("|")[1]
Write-Verbose "latest version based on sources is '$ver'"
[regex]$prereleaseVersionRegex = "\d+\.\d+(\.\d+(\.\d+)?)?\-"
$verMatches = $prereleaseVersionRegex.Match($ver)
if ($verMatches.Success) {
  [int]$verNum = 0
  $baseVer = $verMatches.Value
  $baseExt = $ver -replace $baseVer
  if ($baseExt -match ".+\d+$") {
    $verNum = $baseExt -replace ".+[^0-9]"
    $baseExt = $baseExt -replace "$verNum$"
  }
  Write-Verbose "version base is '$baseVer'"
  Write-Verbose "prerelease extension is '$baseExt'"
  Write-Verbose "old prerelease version is '$verNum'"
  $verNum++
  return "$baseVer$baseExt$verNum"
}
else {
  Write-Verbose "no prerelease tag found - creating one!"
  return "$ver-pre1"
}