fix(queue): time-bound queue-health history for the 30-day trend window (#10020)

Read queue-health snapshots through listRecentSignalSnapshotsForTargets with the
same trendSince window as totals, sized by QUEUE_TREND_SNAPSHOT_LIMIT.

Author: andriypolanski

src/db/repositories.ts

@@ -6190,7 +6190,10 @@ export async function listRecentSignalSnapshotsForTargets(
 ): Promise<Map<string, SignalSnapshotRecord[]>> {
   const result = new Map<string, SignalSnapshotRecord[]>();
   if (targetKeys.length === 0) return result;
-  const perTargetLimit = Math.max(1, Math.min(maxPerTarget, 100));
+  // #10020 / #9699: allow caps large enough for multi-week daily snapshot series (e.g. QUEUE_TREND_SNAPSHOT_LIMIT
+  // = 140). The previous hard 100 matched listSignalSnapshots' latest-row backstop and re-truncated time-bounded
+  // history that needed more than 100 in-window rows.
+  const perTargetLimit = Math.max(1, Math.min(maxPerTarget, 500));
   // The time bound (#9699) is applied INSIDE the windowed subquery so row_number() ranks over the in-window
   // set, not the whole table — otherwise a repo with many recent snapshots could rank its cap entirely within
   // the last few days and never surface the older weeks the trend card needs. maxPerTarget stays the backstop.

src/queue/signal-snapshot.ts

@@ -15,14 +15,18 @@ import {
   listRecentMergedPullRequests,
   listRepoGithubTotalsSnapshotHistory,
   listRepoLabels,
+  listRecentSignalSnapshotsForTargets,
   listRepositories,
-  listSignalSnapshots,
   persistSignalSnapshot,
   replaceCollisionEdges,
   upsertRepoQueueTrendSnapshot,
 } from "../db/repositories";
 import { computeRepoOutcomePatterns, REPO_OUTCOME_PATTERNS_SIGNAL } from "../services/repo-outcome-patterns";
-import { buildQueueTrendReport, QUEUE_TREND_HISTORY_DAYS } from "../services/queue-trends";
+import {
+  buildQueueTrendReport,
+  QUEUE_TREND_HISTORY_DAYS,
+  QUEUE_TREND_SNAPSHOT_LIMIT,
+} from "../services/queue-trends";
 import {
   buildCollisionEdges,
   buildCollisionReport,
@@ -119,7 +123,15 @@ async function generateSignalSnapshotForRepo(
       sinceIso: trendSince,
       limit: 120,
     }),
-    listSignalSnapshots(env, "queue-health", repo.fullName),
+    // #10020: same time window as the totals half — listSignalSnapshots' hard 100-row cap otherwise keeps
+    // only ~25 days at 4 rows/day and the 30-day trend window never resolves a queue-health baseline.
+    listRecentSignalSnapshotsForTargets(
+      env,
+      "queue-health",
+      [repo.fullName],
+      QUEUE_TREND_SNAPSHOT_LIMIT,
+      trendSince,
+    ).then((byTarget) => byTarget.get(repo.fullName) ?? []),
   ]);
   const collisions = buildCollisionReport(
     repo.fullName,

src/services/queue-trends.ts

@@ -4,6 +4,9 @@ import { nowIso } from "../utils/json";
 
 const QUEUE_TREND_WINDOWS_DAYS = [7, 14, 30] as const;
 export const QUEUE_TREND_HISTORY_DAYS = 35;
+/** Per-repo row backstop for the queue-health history read (#10020). Sized for ≥4 snapshots/day across
+ *  `QUEUE_TREND_HISTORY_DAYS` so the time bound (`trendSince`) is the primary constraint. */
+export const QUEUE_TREND_SNAPSHOT_LIMIT = QUEUE_TREND_HISTORY_DAYS * 4;
 
 export type QueueTrendWindow = {
   windowDays: 7 | 14 | 30;

test/unit/queue-trends.test.ts

@@ -2,14 +2,20 @@ import { afterEach, describe, expect, it, vi } from "vitest";
 import * as repositoriesModule from "../../src/db/repositories";
 import { getRepoQueueTrendSnapshot, persistRepoGithubTotalsSnapshot, persistSignalSnapshot, upsertPullRequestFromGitHub, upsertRepositoryFromGitHub } from "../../src/db/repositories";
 import { generateSignalSnapshots } from "../../src/queue/processors";
-import { buildQueueTrendReport, buildUnavailableQueueTrendReport, type QueueTrendReport } from "../../src/services/queue-trends";
+import { buildQueueTrendReport, buildUnavailableQueueTrendReport, QUEUE_TREND_HISTORY_DAYS, QUEUE_TREND_SNAPSHOT_LIMIT, type QueueTrendReport } from "../../src/services/queue-trends";
 import type { RepoGithubTotalsSnapshotRecord } from "../../src/types";
 import { createTestEnv } from "../helpers/d1";
 
 describe("queue trend windows", () => {
   afterEach(() => {
     vi.restoreAllMocks();
   });
+
+  it("keeps QUEUE_TREND_SNAPSHOT_LIMIT sized for four rows/day across the history window (#10020)", () => {
+    expect(QUEUE_TREND_HISTORY_DAYS).toBeGreaterThanOrEqual(30);
+    expect(QUEUE_TREND_SNAPSHOT_LIMIT).toBeGreaterThanOrEqual(QUEUE_TREND_HISTORY_DAYS * 4);
+  });
+
   it("builds deterministic 7/14/30-day queue pressure and review velocity windows", () => {
     const report = buildQueueTrendReport({
       repoFullName: "owner/repo",

test/unit/signal-snapshot-queue-trend-history.test.ts

@@ -0,0 +1,137 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import {
+  getRepoQueueTrendSnapshot,
+  persistRepoGithubTotalsSnapshot,
+  persistSignalSnapshot,
+  upsertPullRequestFromGitHub,
+  upsertRepositoryFromGitHub,
+} from "../../src/db/repositories";
+import { generateSignalSnapshots } from "../../src/queue/processors";
+import type { QueueTrendReport } from "../../src/services/queue-trends";
+import type { RepoGithubTotalsSnapshotRecord } from "../../src/types";
+import { createTestEnv } from "../helpers/d1";
+
+const REPO = "owner/trend-history";
+const FIXTURE_NOW_MS = Date.parse("2026-07-31T12:00:00.000Z");
+
+describe("signal-snapshot queue-trend history window (#10020)", () => {
+  beforeEach(() => {
+    vi.useFakeTimers({ now: FIXTURE_NOW_MS });
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("REGRESSION: time-bounded queue-health history lets the 30-day window resolve duplicate and stale deltas", async () => {
+    const env = createTestEnv();
+    await upsertRepositoryFromGitHub(
+      env,
+      { name: "trend-history", full_name: REPO, private: false, owner: { login: "owner" }, default_branch: "main" },
+      801,
+    );
+    await env.DB.prepare("update repositories set is_registered = 1 where full_name = ?").bind(REPO).run();
+    await upsertPullRequestFromGitHub(env, REPO, {
+      number: 1,
+      title: "Open fix",
+      state: "open",
+      user: { login: "miner" },
+      author_association: "NONE",
+      labels: [],
+      body: "Fixes #1",
+      created_at: atDaysAgo(40),
+      updated_at: atDaysAgo(0),
+    });
+
+    // 130 queue-health rows across ~33 days at four/day — under the old listSignalSnapshots(limit 100)
+    // only ~25 days remained and the 30-day baseline stayed null.
+    let id = 0;
+    for (let day = 32; day >= 0; day -= 1) {
+      for (let slot = 0; slot < 4; slot += 1) {
+        if (id >= 130) break;
+        const daysAgo = day + slot / 4;
+        await persistSignalSnapshot(env, {
+          id: `qh-${id}`,
+          signalType: "queue-health",
+          targetKey: REPO,
+          repoFullName: REPO,
+          generatedAt: atDaysAgo(daysAgo),
+          payload: {
+            signals: {
+              openPullRequests: 10 + Math.floor(daysAgo),
+              stalePullRequests: 1 + Math.floor(daysAgo / 10),
+              collisionClusters: 1 + Math.floor((32 - day) / 8),
+            },
+          },
+        });
+        id += 1;
+      }
+    }
+
+    for (const daysAgo of [33, 30, 14, 7, 0]) {
+      await persistRepoGithubTotalsSnapshot(env, totals(daysAgo, {
+        openIssues: 10 + daysAgo,
+        openPrs: 4 + Math.floor(daysAgo / 5),
+        merged: 20 - Math.floor(daysAgo / 3),
+        closed: 5,
+      }));
+    }
+
+    await generateSignalSnapshots(env, REPO);
+
+    const snapshot = await getRepoQueueTrendSnapshot(env, REPO);
+    const report = snapshot?.payload as unknown as QueueTrendReport;
+    const window30 = report?.windows.find((window) => window.windowDays === 30);
+    expect(window30).toMatchObject({
+      status: "ready",
+      duplicateTrend: expect.any(Number),
+      stalePullRequestRateDelta: expect.any(Number),
+    });
+    expect(window30?.duplicateTrend).not.toBeNull();
+    expect(window30?.stalePullRequestRateDelta).not.toBeNull();
+  });
+
+  it("a repo with no queue-health history still persists a trend (map-miss ?? [] arm) with unavailable windows when totals are missing", async () => {
+    const env = createTestEnv();
+    await upsertRepositoryFromGitHub(
+      env,
+      { name: "empty-history", full_name: "owner/empty-history", private: false, owner: { login: "owner" }, default_branch: "main" },
+      802,
+    );
+
+    await generateSignalSnapshots(env, "owner/empty-history");
+
+    const snapshot = await getRepoQueueTrendSnapshot(env, "owner/empty-history");
+    const report = snapshot?.payload as unknown as QueueTrendReport;
+    expect(report).toMatchObject({
+      status: "unavailable",
+      windows: [
+        expect.objectContaining({ windowDays: 7, status: "unavailable" }),
+        expect.objectContaining({ windowDays: 14, status: "unavailable" }),
+        expect.objectContaining({ windowDays: 30, status: "unavailable" }),
+      ],
+    });
+  });
+});
+
+function totals(
+  daysAgo: number,
+  values: { openIssues: number; openPrs: number; merged: number; closed: number },
+): RepoGithubTotalsSnapshotRecord {
+  return {
+    id: `totals-${daysAgo}-${REPO}`,
+    repoFullName: REPO,
+    openIssuesTotal: values.openIssues,
+    openPullRequestsTotal: values.openPrs,
+    mergedPullRequestsTotal: values.merged,
+    closedUnmergedPullRequestsTotal: values.closed,
+    labelsTotal: 0,
+    sourceKind: "test",
+    fetchedAt: atDaysAgo(daysAgo),
+    payload: {},
+  };
+}
+
+function atDaysAgo(daysAgo: number): string {
+  return new Date(FIXTURE_NOW_MS - daysAgo * 24 * 60 * 60 * 1000).toISOString();
+}