A TeamCity metarunner to set .Net assembly version from Git release/tag

gistfile1.xml

<?xml version="1.0" encoding="UTF-8"?>
<meta-runner name="Set Assembly Version from Git Release/Tag">
  <description>Set the version of all assemblies to the value of the Git tag.</description>
  <settings>
    <parameters>
      <param name="autoinc.path" value="%autoinc.path%" spec="text description='The file containing per-configuration, per-branch build counters. Will be created if it does not exist.' display='normal' label='Build Counter Data File Path' validationMode='not_empty'" />
    </parameters>
    <build-runners>
      <runner name="Set Assembly Version from Git Release/Tag" type="jetbrains_powershell">
        <parameters>
          <param name="jetbrains_powershell_bitness" value="x86" />
          <param name="jetbrains_powershell_execution" value="PS1" />
          <param name="jetbrains_powershell_script_code"><![CDATA[function Update-SourceVersion($ver, $fileVer, $infoVer)
{
    $newVer = "AssemblyVersion(""$ver"")"
    $newFileVer = "AssemblyFileVersion(""$fileVer"")"
    $newInfoVer = "AssemblyInformationalVersion(""$infoVer"")"

  foreach ($o in $input) 
  {
    Write-output $o.FullName
    $TmpFile = $o.FullName + ".tmp"

     get-content $o.FullName | 
        %{$_ -replace 'AssemblyVersion\("[0-9]+(\.([0-9]+|\*)){1,3}"\)', $newVer } |
        %{$_ -replace 'AssemblyFileVersion\("[0-9]+(\.([0-9]+|\*)){1,3}"\)', $newFileVer } |
        %{$_ -replace 'AssemblyInformationalVersion\("[0-9]+(\.([0-9]+|\*)){1,3}"\)', $newInfoVer } > $TmpFile

     move-item $TmpFile $o.FullName -force
  }
}

function GetNextIncrement($buildId, $release)
{
    $ht = @{}
    $increment = 0;
    $key = $buildId+$release;
    
    $autoincPath = "%autoinc.path%"
    Write-Host "Using versions file at $autoincPath"

    # if the autoinc file exists, deserialize the data into a hashtable.
    if(Test-Path -Path $autoincPath)
    {
        $json = Get-Content $autoincPath | ConvertFrom-Json
        $json.psobject.properties | Foreach { $ht[$_.Name] = $_.Value }
    }
    
    # if there is an existing increment for this $key, then fetch it.
    if ($ht.ContainsKey($key))
    {
        $increment = $ht.Get_Item($key)
        Write-Host "Last increment of $key is $increment"
    }

    # increment the increment.
    $increment = 1 + $increment;
    Write-Host "New increment of $key is $increment"

    # if the autoinc file exists, persist the hashtable back to disk.
    if(Test-Path -Path $autoincPath)
    {
      # update the hashtable...
      $ht.Set_Item($key, $increment);
      # ...and write it to disk.   
      ConvertTo-Json $ht -Compress | Set-Content $autoincPath 
    }

    return $increment;
}

$version = "%build.number%"
$branch = "%teamcity.build.branch%"

$beta = 0;
$suffix = "";


if ($branch -match "[\d]+.[\d]+(.[\d]+)?" -or $branch -match "master")
{ 
    ### master
    if ($branch -match "master")
    {
        $version = git describe --abbrev=0
        $patchBase = 200;
    }
    ### release / hotfix
    else
    {
        $version = $branch
        $patchBase = 100;
        $beta = GetNextIncrement "%system.teamcity.buildType.id%" "$branch"
        $suffix = "-beta$beta"
    }

    $version = $version.Trim().TrimStart("v");
    $parts = $version.Split(".")
    $major = $parts[0]
    $minor = $parts[1]
    $patch = @{$true=$parts[2];$false=0}[$parts.Length -eq 3] 
    $patchFull = $patchBase + 10*$patch + $beta

    $fileVersion = "$major.$minor.$patchFull"
    $infoVersion = "$major.$minor.$patch$suffix"
}
### develop / feature branch
else
{
    $fileVersion = $version;
    $infoVersion = $version
}

Write-Host "Updating versions to $version / $fileVersion / $infoVersion..."
Write-Host "##teamcity[buildNumber '$infoVersion']"

foreach ($file in "AssemblyInfo.cs", "AssemblyInfo.vb" ) 
{
  get-childitem -recurse |? {$_.Name -eq $file} | Update-SourceVersion $version $fileVersion $infoVersion;
}

Write-Host "Done"]]></param>
          <param name="jetbrains_powershell_script_mode" value="CODE" />
          <param name="teamcity.step.mode" value="default" />
        </parameters>
      </runner>
    </build-runners>
    <requirements />
  </settings>
</meta-runner>