Add null check for $host.UI and its properties to avoid race condition (

#2383)
pester · May 20, 2024 · 12de632 · 12de632
1 parent eaa36ae
commit 12de632
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/functions/Output.ps1 b/src/functions/Output.ps1
@@ -1162,7 +1162,8 @@ function Resolve-OutputConfiguration ([PesterConfiguration]$PesterPreference) {
             # https://no-color.org/)
             $PesterPreference.Output.RenderMode = 'Plaintext'
         }
-        elseif (($supportsVT = $host.UI.psobject.Properties['SupportsVirtualTerminal']) -and $supportsVT.Value) {
+        # Null check $host.UI and its properties to avoid race condition when accessing them from multiple threads. https://github.com/pester/Pester/issues/2383
+        elseif ($null -ne $host.UI -and ($hostProperties = $host.UI.psobject.Properties) -and ($supportsVT = $hostProperties['SupportsVirtualTerminal']) -and $supportsVT.Value) {
             $PesterPreference.Output.RenderMode = 'Ansi'
         }
         else {