A script to update version numbers in .NET builds, based on the tag name, date, and GitHub action run number. Creates unique version strings for each build.

Update-AssemblyInfoVersionFiles.ps1

$ErrorActionPreference = "Stop"

function Update-AssemblyInfoVersionFiles ([string]$versionIdentifier)
{
  $srcPath = $pwd
  $today = [DateTime]::Today
  $ghref = [System.IO.Path]::GetFileName("$env:GITHUB_REF")
  if ($ghref -match "^(\d+\.\d+)(\-.+)?$") {
    $buildNumber = "{0:yy}{1}.{2}" -f $today,$today.DayOfYear,($env:GITHUB_RUN_NUMBER % [int16]::MaxValue)
    $version = "$($Matches[1]).$buildNumber"
  } elseif ($ghref  -match "^(\d+\.\d+\.\d+)(\-.+)?$") {
    $buildNumber = $env:GITHUB_RUN_NUMBER % [int16]::MaxValue
    $version = "$($Matches[1]).$buildNumber"
  } else {
    Write-Error "Invalid tag name for the release."
  }

  Write-Host "Updating $versionIdentifier in path $srcPath for version $version"

  foreach ($file in $(Get-ChildItem -Path $srcPath -Include "*.fsproj","*.csproj","*.nuspec" -recurse))
  {
    $r = [regex]"<$versionIdentifier>([0-9]+\.[0-9]+)(\.([0-9]+|\*))+"
    Write-Host "Processing '$($file.FullName)'"
    #version replacements
    (Get-Content -Encoding utf8 $file.FullName) | % {
      $m = $r.Matches($_)
      if ($m -and $m.Success) {
        $s = $r.Replace($_, "<$versionIdentifier>$version")
        Write-Host "Change version to $s"
        $s
      } else {
        $_
      }
    } | Set-Content -Encoding utf8 $file.FullName -Force
  }

  foreach ($file in $(Get-ChildItem -Path $srcPath -Include "AssemblyInfo.cs" -recurse))
  {
    $r = [regex]"$versionIdentifier\(`"([0-9]+\.[0-9]+)(\.([0-9]+|\*))+`"\)"
    Write-Host "Processing '$($file.FullName)'"
    #version replacements
    (Get-Content -Encoding utf8 $file.FullName) | % {
      $m = $r.Matches($_)
      if ($m -and $m.Success) {
        $s = $r.Replace($_, "$versionIdentifier(`"$version`")")
        Write-Host "Change version to $s"
        $s
      } else {
        $_
      }
    } | Set-Content -Encoding utf8 $file.FullName -Force
  }
}

Update-AssemblyInfoVersionFiles "FileVersion" -Verbose
Update-AssemblyInfoVersionFiles "AssemblyVersion" -Verbose
Update-AssemblyInfoVersionFiles "version" -Verbose
Update-AssemblyInfoVersionFiles "Version" -Verbose
Update-AssemblyInfoVersionFiles "PackageVersion" -Verbose