From 0ebfafa98b603624511179b819275c300f8dacfc Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Thu, 22 Oct 2026 08:39:11 -0400
Subject: [PATCH] fix(centralui): safe-invoke fire-and-forget calls in
 AlarmSummary and TreeView (review 2026-10-21 07/M-4)

---
 .../Pages/Monitoring/AlarmSummary.razor          | 12 +++++++++++-
 .../Components/Shared/TreeView.razor             | 16 ++++++++++++++--
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Monitoring/AlarmSummary.razor b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Monitoring/AlarmSummary.razor
index 3c8935ef..39035890 100644
--- a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Monitoring/AlarmSummary.razor
+++ b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Monitoring/AlarmSummary.razor
@@ -449,7 +449,7 @@
     private void OnLiveAlarmsChanged(int siteId)
     {
         if (_disposed) return;
-        _ = InvokeAsync(() =>
+        _ = SafeInvokeAsync(() =>
         {
             // Drop stale callbacks for a site we've since navigated away from, and
             // let the poll drive until the aggregator has actually seeded (so we never
@@ -464,6 +464,16 @@
         });
     }
 
+    // Runs the action on the render thread; a callback racing circuit teardown makes
+    // InvokeAsync throw ObjectDisposedException into an otherwise-unobserved task
+    // (pattern from DebugView.SafeInvokeAsync).
+    private async Task SafeInvokeAsync(Action action)
+    {
+        if (_disposed) return;
+        try { await InvokeAsync(action); }
+        catch (ObjectDisposedException) { /* disposed between the guard and the dispatch */ }
+    }
+
     // Rebuilds rows/rollup/visible-rows from the live snapshot. Leaves _notReporting
     // as the last poll computed it (the alarm-only cache can't know it). Idempotent.
     private void ApplyLiveSnapshot(int siteId)
diff --git a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/TreeView.razor b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/TreeView.razor
index 72c854ba..c1b53274 100644
--- a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/TreeView.razor
+++ b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/TreeView.razor
@@ -207,7 +207,7 @@ else
         // Clear selection if the selected key no longer exists in the current items tree
         if (Selectable && SelectedKey != null && _items is not null && !KeyExistsInTree(_items, SelectedKey))
         {
-            _ = SelectedKeyChanged.InvokeAsync(null);
+            _ = SafeFireAndForgetAsync(() => SelectedKeyChanged.InvokeAsync(null));
         }
     }
 
@@ -553,10 +553,22 @@ else
         if (StorageKey != null)
         {
             var json = System.Text.Json.JsonSerializer.Serialize(_expandedKeys.ToList());
-            _ = JSRuntime.InvokeVoidAsync("treeviewStorage.save", StorageKey, json);
+            _ = SafeFireAndForgetAsync(() =>
+                JSRuntime.InvokeVoidAsync("treeviewStorage.save", StorageKey, json).AsTask());
         }
     }
 
+    // Fire-and-forget calls (an EventCallback, a JS persist) can race circuit teardown;
+    // swallow the expected disposal/disconnect failures so no unobserved-task exception
+    // reaches the log (review 2026-10-21 07/M-4).
+    private static async Task SafeFireAndForgetAsync(Func<Task> work)
+    {
+        try { await work(); }
+        catch (ObjectDisposedException) { }
+        catch (JSDisconnectedException) { }
+        catch (TaskCanceledException) { }
+    }
+
     private async Task OnContentClick(object key)
     {
         // Clicking a node makes it the tab entry point (roving tabindex follows the