fix(health): flag metrics-stale for never-reported sites via FirstSeenAt anchor — null LastReportReceivedAt no longer skips the check (plan R2-01 T8)

2026-07-13 10:45:22 -04:00
parent e4765b2eed
commit 11efe4be05
4 changed files with 55 additions and 5 deletions
@@ -513,4 +513,35 @@ public class CentralHealthAggregatorTests
        aggregator.MarkHeartbeat("site-a", time.GetUtcNow());
        Assert.NotEqual(offlineAt, aggregator.GetSiteState("site-a")!.LastStatusChangeAt);
    }
+
+    /// <summary>
+    /// Round-2 N3: a site known only via heartbeats (LastReportReceivedAt == null)
+    /// previously skipped the staleness check forever — a report pipeline dead
+    /// from FIRST BOOT showed "online with no metrics" indefinitely. FirstSeenAt
+    /// anchors the window instead (LastHeartbeatAt cannot: heartbeats advance it).
+    /// </summary>
+    [Fact]
+    public void HeartbeatOnlySite_NeverReported_IsFlaggedMetricsStale()
+    {
+        var (aggregator, time) = NewAggregator(metricsStaleTimeout: TimeSpan.FromMinutes(2));
+        aggregator.MarkHeartbeat("site-a", time.GetUtcNow());   // registered via heartbeat only
+        time.Advance(TimeSpan.FromMinutes(3));
+        aggregator.MarkHeartbeat("site-a", time.GetUtcNow());   // still heartbeating => online
+        aggregator.CheckForOfflineSites();
+        var state = aggregator.GetSiteState("site-a")!;
+        Assert.True(state.IsOnline);                             // liveness unchanged
+        Assert.True(state.IsMetricsStale);                       // was impossible before the fix
+    }
+
+    /// <summary>A heartbeat-only site inside the window is NOT falsely flagged.</summary>
+    [Fact]
+    public void HeartbeatOnlySite_WithinStaleWindow_IsNotFlagged()
+    {
+        var (aggregator, time) = NewAggregator(metricsStaleTimeout: TimeSpan.FromMinutes(2));
+        aggregator.MarkHeartbeat("site-a", time.GetUtcNow());
+        time.Advance(TimeSpan.FromMinutes(1));
+        aggregator.MarkHeartbeat("site-a", time.GetUtcNow());
+        aggregator.CheckForOfflineSites();
+        Assert.False(aggregator.GetSiteState("site-a")!.IsMetricsStale);
+    }
 }