From e665888a45d933c229aefe73c2a05e125290b983 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Fri, 13 Mar 2026 21:51:01 +0000
Subject: [PATCH] test: tighten shared usage aggregate coverage

---
 src/shared/usage-aggregates.test.ts | 42 +++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/src/shared/usage-aggregates.test.ts b/src/shared/usage-aggregates.test.ts
index e5ba960ad95..dc6896b7490 100644
--- a/src/shared/usage-aggregates.test.ts
+++ b/src/shared/usage-aggregates.test.ts
@@ -16,6 +16,13 @@ describe("shared/usage-aggregates", () => {
     };
 
     mergeUsageLatency(totals, undefined);
+    mergeUsageLatency(totals, {
+      count: 0,
+      avgMs: 999,
+      minMs: 1,
+      maxMs: 999,
+      p95Ms: 999,
+    });
     mergeUsageLatency(totals, {
       count: 2,
       avgMs: 50,
@@ -51,6 +58,7 @@ describe("shared/usage-aggregates", () => {
       { date: "2026-03-12", count: 1, avgMs: 120, minMs: 120, maxMs: 120, p95Ms: 120 },
       { date: "2026-03-11", count: 1, avgMs: 30, minMs: 30, maxMs: 30, p95Ms: 30 },
     ]);
+    mergeUsageDailyLatency(dailyLatencyMap, null);
 
     const tail = buildUsageAggregateTail({
       byChannelMap: new Map([
@@ -114,4 +122,38 @@ describe("shared/usage-aggregates", () => {
     expect(tail.latency).toBeUndefined();
     expect(tail.dailyLatency).toEqual([]);
   });
+
+  it("normalizes zero-count daily latency entries to zero averages and mins", () => {
+    const dailyLatencyMap = new Map([
+      [
+        "2026-03-12",
+        {
+          date: "2026-03-12",
+          count: 0,
+          sum: 0,
+          min: Number.POSITIVE_INFINITY,
+          max: 0,
+          p95Max: 0,
+        },
+      ],
+    ]);
+
+    const tail = buildUsageAggregateTail({
+      byChannelMap: new Map(),
+      latencyTotals: {
+        count: 0,
+        sum: 0,
+        min: Number.POSITIVE_INFINITY,
+        max: 0,
+        p95Max: 0,
+      },
+      dailyLatencyMap,
+      modelDailyMap: new Map(),
+      dailyMap: new Map(),
+    });
+
+    expect(tail.dailyLatency).toEqual([
+      { date: "2026-03-12", count: 0, avgMs: 0, minMs: 0, maxMs: 0, p95Ms: 0 },
+    ]);
+  });
 });