Check if powershell code is executed as part of a Pester test

Test-PesterInvocation.ps1

  function Test-PesterInvocation {
      $commandStack=Get-PSCallStack | Select-Object -ExpandProperty Command

      #region Render
      <#
      for($i=$commandStack.Count-1;$i -ge 0;$i--)
      {
          $prefix="+".PadRight($commandStack.Count-1-$i,'-')
          Write-Host ($prefix+$commandStack[$i])
      }
      #>
      #endregion

      ($commandStack -contains "Invoke-Pester") -or ($commandStack -contains "Describe")
  }

if you would enable the render section for troubleshooting it would look like this

+Describe
+-<ScriptBlock>
+--It
+---ItImpl
+----Invoke-Test
+-----<ScriptBlock>
+------Should
+-------Get-TestResult
+--------PesterThrow
+---------<ScriptBlock>
+----------Get-SCTAStageFolderPath
+-----------Test-PesterInvocation