feat(kpi): GetLatestRollupHourAsync watermark seam for the backfill fast-path (plan R2-04 T2)

2026-07-13 09:44:57 -04:00
parent 29c1286943
commit a1c7c4ef26
4 changed files with 54 additions and 0 deletions
@@ -406,6 +406,29 @@ public class KpiHistoryRepositoryTests
        Assert.Empty(ctx.ChangeTracker.Entries<KpiSample>());
    }

+    [Fact]
+    public async Task GetLatestRollupHour_ReturnsNull_WhenNoRollupsExist()
+    {
+        await using var ctx = NewContext();
+        var repo = new KpiHistoryRepository(ctx);
+        Assert.Null(await repo.GetLatestRollupHourAsync());
+    }
+
+    [Fact]
+    public async Task GetLatestRollupHour_ReturnsNewestHourStart_AcrossAllSeries()
+    {
+        await using var ctx = NewContext();
+        var repo = new KpiHistoryRepository(ctx);
+        await repo.RecordSamplesAsync(new[]
+        {
+            Sample("NotificationOutbox", "queueDepth", "Global", null, 5, Base.AddMinutes(10)),
+            Sample("SiteCallAudit", "buffered", "Global", null, 2, Base.AddHours(3).AddMinutes(10)),
+        });
+        await repo.FoldHourlyRollupsAsync(Base, Base.AddHours(4));
+
+        Assert.Equal(Base.AddHours(3), await repo.GetLatestRollupHourAsync());
+    }
+
    // Local mirror of the repo's private hour-truncation, for cutoff assertions.
    private static DateTime TruncateHour(DateTime utc) =>
        new(utc.Year, utc.Month, utc.Day, utc.Hour, 0, 0, DateTimeKind.Utc);