[rel/5.6.x] Fix NRE in mock debug log for native commands (#2481)

* Fix NRE in mock debug log for native commands

* Exclude for commands without parameters

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Co-authored-by: Frode Flaten <[email protected]>

Author: github-actions[bot]

src/functions/Mock.ps1

@@ -411,7 +411,10 @@ function Should-InvokeInternal {
     $nonMatchingCalls = [System.Collections.Generic.List[object]]@()
 
     # Check for variables in ParameterFilter that already exists in session. Risk of conflict
-    if ($PesterPreference.Debug.WriteDebugMessages.Value) {
+    # Excluding native applications as they don't have parameters or metadata. Will always use $args
+    if ($PesterPreference.Debug.WriteDebugMessages.Value -and
+        $null -ne $ContextInfo.Hook.Metadata -and
+        $ContextInfo.Hook.Metadata.Parameters.Count -gt 0) {
         $preExistingFilterVariables = @{}
         foreach ($v in $filter.Ast.FindAll( { $args[0] -is [System.Management.Automation.Language.VariableExpressionAst] }, $true)) {
             if (-not $preExistingFilterVariables.ContainsKey($v.VariablePath.UserPath)) {