review(Client.UI): single notification when removing non-retained alarm row

Re-review at 7286d320. -013: AlarmsViewModel.OnAlarmEvent removal path no longer fires a redundant Replace+Remove (one Remove now), preventing a DataGrid re-paint flash. -012: add update/remove-path test coverage. + TDD.
2026-06-19 11:58:15 -04:00
parent d68c9db9f9
commit 12efbffd56
3 changed files with 158 additions and 7 deletions
@@ -153,6 +153,101 @@ public class AlarmsViewModelTests
        _vm.Interval.ShouldBe(1000);
    }

+    // --- Alarm update and non-retain remove paths (Client.UI-012 / Client.UI-013) ---
+
+    /// <summary>
+    /// Regression test for Client.UI-013 / Client.UI-012 — a second event for the same
+    /// source+condition must update the existing row in place rather than adding a duplicate.
+    /// </summary>
+    [Fact]
+    public void AlarmEvent_ExistingAlarm_UpdatesInPlace()
+    {
+        var first = new AlarmEventArgs(
+            "Source1", "HighAlarm", 500, "Temperature high",
+            retain: true, activeState: true, ackedState: false, time: DateTime.UtcNow);
+        _service.RaiseAlarmEvent(first);
+
+        var updated = new AlarmEventArgs(
+            "Source1", "HighAlarm", 750, "Temperature very high",
+            retain: true, activeState: true, ackedState: false, time: DateTime.UtcNow);
+        _service.RaiseAlarmEvent(updated);
+
+        _vm.AlarmEvents.Count.ShouldBe(1);
+        _vm.AlarmEvents[0].Severity.ShouldBe((ushort)750);
+        _vm.AlarmEvents[0].Message.ShouldBe("Temperature very high");
+    }
+
+    /// <summary>
+    /// Regression test for Client.UI-013 — when an existing retained alarm becomes
+    /// non-retained the row must be removed from the collection with exactly ONE collection
+    /// mutation (not a Replace + Remove pair).
+    /// </summary>
+    [Fact]
+    public void AlarmEvent_ExistingAlarmBecomesNonRetained_IsRemovedCleanly()
+    {
+        // Seed a retained alarm.
+        var first = new AlarmEventArgs(
+            "Source1", "HighAlarm", 500, "Active",
+            retain: true, activeState: true, ackedState: false, time: DateTime.UtcNow);
+        _service.RaiseAlarmEvent(first);
+        _vm.AlarmEvents.Count.ShouldBe(1);
+
+        // Track collection-change notifications.
+        var changeCount = 0;
+        _vm.AlarmEvents.CollectionChanged += (_, _) => changeCount++;
+
+        // Now the alarm is cleared (Retain = false).
+        var cleared = new AlarmEventArgs(
+            "Source1", "HighAlarm", 500, "Cleared",
+            retain: false, activeState: false, ackedState: false, time: DateTime.UtcNow);
+        _service.RaiseAlarmEvent(cleared);
+
+        // Row must be removed.
+        _vm.AlarmEvents.ShouldBeEmpty();
+        // Exactly one collection-change notification (Remove), not two (Replace then Remove).
+        changeCount.ShouldBe(1);
+    }
+
+    /// <summary>
+    /// Verifies that a non-retained alarm that has no existing row in the collection
+    /// is silently dropped (not added).
+    /// </summary>
+    [Fact]
+    public void AlarmEvent_NonRetained_WithNoExistingRow_IsNotAdded()
+    {
+        var nonRetained = new AlarmEventArgs(
+            "Source1", "HighAlarm", 500, "Already cleared",
+            retain: false, activeState: false, ackedState: false, time: DateTime.UtcNow);
+        _service.RaiseAlarmEvent(nonRetained);
+
+        _vm.AlarmEvents.ShouldBeEmpty();
+    }
+
+    /// <summary>
+    /// Verifies that ActiveAlarmCount is updated correctly when an alarm is acknowledged
+    /// via an event update (AckedState changes from false to true).
+    /// </summary>
+    [Fact]
+    public void AlarmEvent_AcknowledgedUpdate_DecrementsActiveAlarmCount()
+    {
+        // Seed an unacknowledged active alarm.
+        var active = new AlarmEventArgs(
+            "Source1", "HighAlarm", 500, "Active",
+            retain: true, activeState: true, ackedState: false, time: DateTime.UtcNow);
+        _service.RaiseAlarmEvent(active);
+        _vm.ActiveAlarmCount.ShouldBe(1);
+
+        // Acknowledge the alarm.
+        var acked = new AlarmEventArgs(
+            "Source1", "HighAlarm", 500, "Acked",
+            retain: true, activeState: true, ackedState: true, time: DateTime.UtcNow);
+        _service.RaiseAlarmEvent(acked);
+
+        _vm.AlarmEvents.Count.ShouldBe(1);
+        _vm.AlarmEvents[0].AckedState.ShouldBeTrue();
+        _vm.ActiveAlarmCount.ShouldBe(0);
+    }
+
    /// <summary>
    /// Regression test for Client.UI-006 — when SubscribeAlarmsAsync throws, the failure must be
    /// surfaced to the operator via the view model's StatusMessage rather than silently swallowed.