Fixes #4391. Weird situation where ForceDriver with args doesn't persists on open scenario

Examples/UICatalog/UICatalog.cs

@@ -55,13 +55,31 @@ namespace UICatalog;
 /// </remarks>
 public class UICatalog
 {
-    private static string? _forceDriver = null;
+    private static string? _forceDriver;
+    private static bool _forTesting;
+    private static bool _iterationHandlerRemoved;
+    private static string? _uiCatalogDriver;
+    private static string? _scenarioDriver;
 
     public static string LogFilePath { get; set; } = string.Empty;
     public static LoggingLevelSwitch LogLevelSwitch { get; } = new ();
     public const string LOGFILE_LOCATION = "logs";
     public static UICatalogCommandLineOptions Options { get; set; }
 
+    public static (string? UiCatalogDriver, string? ScenarioDriver) Run (string [] args)
+    {
+        // Flag for testing
+        _forTesting = true;
+
+        // Start app
+        Main (args);
+
+        // Unset testing flag
+        _forTesting = false;
+
+        return new (_uiCatalogDriver, _scenarioDriver);
+    }
+
     private static int Main (string [] args)
     {
         Console.OutputEncoding = Encoding.Default;
@@ -194,6 +212,8 @@ public class UICatalog
 
         UICatalogMain (Options);
 
+        Debug.Assert (Application.ForceDriver == string.Empty);
+
         return 0;
     }
 
@@ -247,6 +267,11 @@ public class UICatalog
     /// <returns></returns>
     private static Scenario RunUICatalogTopLevel ()
     {
+        if (_iterationHandlerRemoved)
+        {
+            return null!;
+        }
+
         // Run UI Catalog UI. When it exits, if _selectedScenario is != null then
         // a Scenario was selected. Otherwise, the user wants to quit UI Catalog.
 
@@ -255,7 +280,22 @@ public class UICatalog
 
         Application.Init (driverName: _forceDriver);
 
-        var top = Application.Run<UICatalogTop> ();
+        Toplevel top;
+
+        if (_forTesting)
+        {
+            top = new UICatalogTop ();
+            SessionToken sessionToken = Application.Begin (top);
+            UICatalogTop.CachedSelectedScenario = Scenario.GetScenarios () [0];
+            Application.End (sessionToken);
+
+            _uiCatalogDriver = Application.Driver!.GetName ();
+        }
+        else
+        {
+            top = Application.Run<UICatalogTop> ();
+        }
+
         top.Dispose ();
         Application.Shutdown ();
         VerifyObjectsWereDisposed ();
@@ -412,6 +452,8 @@ public class UICatalog
             Application.InitializedChanged += ApplicationOnInitializedChanged;
 #endif
 
+            Application.ForceDriver = _forceDriver;
+
             scenario.Main ();
             scenario.Dispose ();
 
@@ -430,6 +472,43 @@ public class UICatalog
                 if (e.Value)
                 {
                     sw.Start ();
+
+                    if (_forTesting)
+                    {
+                        int iterationCount = 0;
+                        Key quitKey;
+
+                        Application.Iteration += OnApplicationOnIteration;
+
+                        void OnApplicationOnIteration (object? s, IterationEventArgs a)
+                        {
+                            iterationCount++;
+
+                            if (Application.Initialized)
+                            {
+                                // Press QuitKey
+                                quitKey = Application.QuitKey;
+
+                                Logging.Trace (
+                                               $"Attempting to quit with {quitKey} after {iterationCount} iterations.");
+
+                                try
+                                {
+                                    Application.RaiseKeyDownEvent (quitKey);
+                                }
+                                catch (Exception ex)
+                                {
+                                    Logging.Trace (
+                                                   $"Exception raising quit key: {ex.Message}");
+                                }
+
+                                Application.Iteration -= OnApplicationOnIteration;
+                                _iterationHandlerRemoved = true;
+
+                                _scenarioDriver = Application.Driver?.GetName ();
+                            }
+                        }
+                    }
                 }
                 else
                 {