Public/Test-TeamCity.ps1

<#
.SYNOPSIS
    Determines whether or not the current script is executing on a TeamCity Build Agent.
 
.OUTPUTS
    Returns $true when running on a build agent; otherwise, $false
#>

Function Test-TeamCity {
    [CmdletBinding()]
    Param ()

    if (Test-Path Env:TEAMCITY_VERSION) {
        Write-Verbose "Currently executing on TeamCity Build Agent" 
        Write-Output $true
    }
    else {
        Write-Verbose "Currently executing in standard PowerShell"
        Write-Output $false
    }
}