TeamCity: Inject github short hash to project.json files of aspnet core

injectGitHashToProjectJson.ps1

$rootDirectory="%teamcity.build.workingDir%"
$gitHash="%build.vcs.number%"

echo "githash is $gitHash"
$gitShortHash=$gitHash.Substring(0,7)
$listOfFiles = @(    
     "$rootDirectory\src\TestProject\project.json"
)

foreach($file in $listOfFiles)
{
    $a = Get-Content $file -raw | ConvertFrom-Json
    $currentVersion = $($a.version)
    #clean up previous github hash
    $currentVersion = $currentVersion -split '-',2 |select-object -first 1
    echo "The current value of $file is $currentVersion"
    $newVersion="$currentVersion-$gitShortHash"
    echo "The new value of version for $file is $newVersion" 
    $a.version=$newVersion
    #regenerate the file with modified node
    $a|ConvertTo-Json -Depth 20|Set-Content $file
}