Fix UI verification state isolation

Editor/MCPTestWindow.cs

@@ -9,7 +9,7 @@ namespace UnityMCP.Editor
     /// </summary>
     /// <remarks>
     /// The window builds a TextField, Button, and Label with stable names. Verification helpers show the window, reset state,
-    /// send UI automation JSON-RPC calls, and assert that UI callbacks update the static test state.
+    /// send UI automation JSON-RPC calls, and assert that UI callbacks update this window's test state.
     /// </remarks>
     public class MCPTestWindow : EditorWindow
     {
@@ -18,15 +18,15 @@ public class MCPTestWindow : EditorWindow
         /// <summary>
         /// Stores the last input value for verification.
         /// </summary>
-        public static string LastInputValue = "";
+        public string LastInputValue { get; private set; } = "";
 
         /// <summary>
         /// Tracks if the test button has been clicked.
         /// </summary>
-        public static bool ButtonClicked = false;
+        public bool ButtonClicked { get; private set; }
 
         /// <summary>
-        /// Resets static test flags and clears the UI Toolkit input/label elements in the current visual tree.
+        /// Resets this window's test state and clears the UI Toolkit input/label elements in the current visual tree.
         /// </summary>
         public void ResetState()
         {
@@ -58,25 +58,22 @@ private void OnEnable()
         /// Creates named UI Toolkit controls and event handlers used by Nexus Unity UI automation smoke tests.
         /// </summary>
         /// <remarks>
-        /// This method mutates <see cref="EditorWindow.rootVisualElement"/>, resets static test state, registers a text-change
+        /// This method mutates <see cref="EditorWindow.rootVisualElement"/>, preserves instance test state, registers a text-change
         /// callback, and wires the button click to update the label and <see cref="ButtonClicked"/>.
         /// </remarks>
         public void CreateGUI()
         {
             NexusEditorUi.SetupRoot(rootVisualElement);
             rootVisualElement.name = "NexusTestWindowRoot";
 
-            LastInputValue = "";
-            ButtonClicked = false;
-
             var header = NexusEditorUi.Panel("TestWindowHeader");
             header.Add(NexusEditorUi.Label("UI Automation Test", 16, true));
             header.Add(NexusEditorUi.Label("Named controls used by Nexus Unity UI automation checks.", 11, false, NexusEditorUi.Muted));
             rootVisualElement.Add(header);
 
             var panel = NexusEditorUi.Panel("TestWindowControls");
 
-            var label = new Label("Initial State");
+            var label = new Label(ButtonClicked ? "Button Clicked!" : "Initial State");
             label.name = "TestLabel";
             label.style.marginBottom = 8;
             label.style.unityFontStyleAndWeight = FontStyle.Bold;
@@ -85,8 +82,7 @@ public void CreateGUI()
             var textField = new TextField("Input:");
             textField.name = "TestInput";
             textField.style.marginBottom = 8;
-            textField.value = "";
-            LastInputValue = textField.value;
+            textField.value = LastInputValue;
             textField.RegisterValueChangedCallback(evt => LastInputValue = evt.newValue);
             panel.Add(textField);
 

Editor/UIVerification.cs

@@ -26,7 +26,7 @@ public static void Verify()
             wnd.ResetState();
 
             TestListAndHierarchy();
-            TestInputAndClick();
+            TestInputAndClick(wnd);
             NexusEditorLog.Log(NexusLogCategory.Diagnostics, "VERIFICATION SUCCESS", true);
         }
 
@@ -38,13 +38,13 @@ private static void TestListAndHierarchy()
             if (!hier.Contains("TestButton")) throw new System.Exception("Hierarchy failed");
         }
 
-        private static void TestInputAndClick()
+        private static void TestInputAndClick(MCPTestWindow wnd)
         {
             string txt = "Test";
             Call("ui_input_text", new JObject { ["window_title"] = MCPTestWindow.WindowTitle, ["element_name"] = "TestInput", ["text"] = txt });
-            if (MCPTestWindow.LastInputValue != txt) throw new System.Exception($"Input failed: expected '{txt}' but got '{MCPTestWindow.LastInputValue}'");
+            if (wnd.LastInputValue != txt) throw new System.Exception($"Input failed: expected '{txt}' but got '{wnd.LastInputValue}'");
             Call("ui_click", new JObject { ["window_title"] = MCPTestWindow.WindowTitle, ["element_name"] = "TestButton" });
-            if (!MCPTestWindow.ButtonClicked) throw new System.Exception("Click failed");
+            if (!wnd.ButtonClicked) throw new System.Exception("Click failed");
         }
 
         private static string Call(string m, JObject p)

Tests~/Editor/EditorWindowUiToolkitTests.cs

@@ -130,6 +130,29 @@ public void TestWindowPreservesAutomationElementNames()
             }
         }
 
+        [Test]
+        public void TestWindowPreservesVerificationStateWhenRebuilt()
+        {
+            var window = ScriptableObject.CreateInstance<MCPTestWindow>();
+            try
+            {
+                window.CreateGUI();
+                window.rootVisualElement.Q<TextField>("TestInput").value = "Persisted";
+                window.rootVisualElement.Q<Button>("TestButton").Click();
+
+                window.CreateGUI();
+
+                Assert.AreEqual("Persisted", window.LastInputValue);
+                Assert.IsTrue(window.ButtonClicked);
+                Assert.AreEqual("Persisted", window.rootVisualElement.Q<TextField>("TestInput").value);
+                Assert.AreEqual("Button Clicked!", window.rootVisualElement.Q<Label>("TestLabel").text);
+            }
+            finally
+            {
+                Object.DestroyImmediate(window);
+            }
+        }
+
         [Test]
         public void ServerWindowAppliesMinimumUsableSize()
         {