fix(ui): drop stale-site poll results on Alarm Summary site switch (plan R2-07 T7)

2026-07-13 10:55:25 -04:00
parent 1fcfa4fb16
commit d33337a834
2 changed files with 43 additions and 0 deletions
@@ -208,6 +208,42 @@ public class AlarmSummaryRenderTests : BunitContext
        Assert.True(_liveCache.DisposeCount >= 1);
    }

+    // ── arch-review R2 N4: stale-site poll guard ───────────────────────────────
+
+    [Fact]
+    public void InFlightPollForPreviousSite_DoesNotOverwriteNewSitesRows()
+    {
+        // Site 1's fan-out hangs on a TCS; site 2 answers immediately (arch-review R2 N4).
+        var site1Tcs = new TaskCompletionSource<AlarmSummaryResult>();
+        _summary.GetSiteAlarmsAsync(1, Arg.Any<CancellationToken>()).Returns(site1Tcs.Task);
+        _summary.GetSiteAlarmsAsync(2, Arg.Any<CancellationToken>()).Returns(Task.FromResult(
+            new AlarmSummaryResult(
+                new List<AlarmSummaryRow>
+                {
+                    new("Site2Instance", new AlarmStateChanged("Site2Instance", "S2-alarm", AlarmState.Active, 100, DateTimeOffset.UtcNow)),
+                },
+                Array.Empty<string>())));
+
+        var cut = Render<AlarmSummaryPage>();
+        cut.Find("[data-test='alarm-summary-site']").Change("1"); // poll in flight, hung
+        cut.Find("[data-test='alarm-summary-site']").Change("2"); // site 2 renders
+        cut.WaitForAssertion(() => Assert.Equal("Site2Instance", FirstRowInstance(cut)));
+
+        // The stale site-1 fan-out now completes — it must be dropped, not rendered.
+        site1Tcs.SetResult(new AlarmSummaryResult(
+            new List<AlarmSummaryRow>
+            {
+                new("StaleSite1", new AlarmStateChanged("StaleSite1", "S1-alarm", AlarmState.Active, 999, DateTimeOffset.UtcNow)),
+            },
+            new[] { "StaleNotReporting" }));
+
+        cut.WaitForAssertion(() =>
+        {
+            Assert.Equal("Site2Instance", FirstRowInstance(cut));
+            Assert.DoesNotContain("StaleNotReporting", cut.Markup);
+        });
+    }
+
    /// <summary>
    /// Controllable in-memory fake of <see cref="ISiteAlarmLiveCache"/>: records
    /// subscribe/dispose counts and lets a test push a live snapshot (which flips