feat(report): lead with the solution and apply review feedback

src/report/aggregate.test.ts

@@ -35,11 +35,27 @@ test('counts merged-in-window PRs and surfaces backlog age buckets', () => {
     mergedInWindowCount: 1,
     oldestOpenDays: expect.any(Number) as number,
   });
-  // The 263-day-old PR should fall into the 180+ bucket.
-  const oldBucket = bundle.prBacklog.openAgeBuckets.find((b) => b.label === '180+ days');
+  // The 263-day-old PR should fall into the 90+ bucket (90 and 180+ are no longer split).
+  const oldBucket = bundle.prBacklog.openAgeBuckets.find((b) => b.label === '90+ days');
   expect(oldBucket?.count).toBe(1);
 });
 
+test('averages open PR age and reports null when nothing is open', () => {
+  // collectionContext.now is 2026-05-22, so these open PRs are 10 and 30 days old.
+  const withOpen = collectedData.build({
+    dependabotPrs: [
+      dependabotPr.build({ state: 'open', createdAt: '2026-05-12T00:00:00Z' }),
+      dependabotPr.build({ state: 'open', createdAt: '2026-04-22T00:00:00Z' }),
+    ],
+  });
+  expect(aggregate(withOpen).prBacklog.openAvgAgeDays).toBe(20);
+
+  const noOpen = collectedData.build({
+    dependabotPrs: [dependabotPr.build({ state: 'closed', merged: true, mergedAt: '2026-04-01T00:00:00Z' })],
+  });
+  expect(aggregate(noOpen).prBacklog.openAvgAgeDays).toBeNull();
+});
+
 test('rolls org/visibility/language counts up into orgOverview', () => {
   const data = collectedData.build({
     repos: [
@@ -180,13 +196,13 @@ test('builds a cost estimate from human merges and reviews, excluding bot merges
   const bundle = aggregate(data);
   expect(bundle.costEstimate.humanMergeCount).toBe(100);
   expect(bundle.costEstimate.humanReviewCount).toBe(0);
-  expect(bundle.costEstimate.hourlyRateUsd).toBe(150);
-  expect(bundle.costEstimate.minutesPerPr).toBe(5);
-  // 100 actions × 5 min × $150/hr / 60 = $1250 in window
-  expect(bundle.costEstimate.windowCostUsd).toBe(1250);
-  // ~$423/month over 90 days (window × 30.44/90)
-  expect(bundle.costEstimate.monthlyCostUsd).toBeGreaterThan(400);
-  expect(bundle.costEstimate.monthlyCostUsd).toBeLessThan(450);
+  expect(bundle.costEstimate.hourlyRateUsd).toBe(200);
+  expect(bundle.costEstimate.minutesPerPr).toBe(12);
+  // 100 actions × 12 min × $200/hr / 60 = $4000 in window
+  expect(bundle.costEstimate.windowCostUsd).toBe(4000);
+  // ~$1,352/month over 90 days (window × 30.44/90)
+  expect(bundle.costEstimate.monthlyCostUsd).toBeGreaterThan(1300);
+  expect(bundle.costEstimate.monthlyCostUsd).toBeLessThan(1400);
   expect(bundle.costEstimate.annualCostUsd).toBe(bundle.costEstimate.monthlyCostUsd * 12);
   expect(bundle.costEstimate.savingsScenarios.map((s) => s.autoMergeRate)).toEqual([0.5, 0.6, 0.7, 0.8]);
   expect(bundle.costEstimate.savingsScenarios[0]?.annualSavingsUsd).toBe(

src/report/aggregate.ts

@@ -60,6 +60,7 @@ export interface PrBacklog {
   mergedInWindowCount: number;
   openAgeBuckets: Array<{ label: string; count: number }>;
   oldestOpenDays: number | null;
+  openAvgAgeDays: number | null;
   bumpTypeSplit: Array<{ bumpType: string; count: number; percentage: number }>;
   devOnlyShare: { count: number; percentage: number };
   ciStatusMix: { green: number; failing: number; pending: number };
@@ -235,19 +236,17 @@ function buildPrBacklog(data: CollectedData, now: Instant, windowStart: Instant)
     { label: '0–30 days', min: 0, max: 30 },
     { label: '30–60 days', min: 30, max: 60 },
     { label: '60–90 days', min: 60, max: 90 },
-    { label: '90–180 days', min: 90, max: 180 },
-    { label: '180+ days', min: 180, max: Number.POSITIVE_INFINITY },
+    { label: '90+ days', min: 90, max: Number.POSITIVE_INFINITY },
   ];
+  const openAges = openPrs.map((p) => daysBetween(now, instantFromString(p.createdAt)));
   const openAgeBuckets = buckets.map((b) => ({
     label: b.label,
-    count: openPrs.filter((p) => {
-      const age = daysBetween(now, instantFromString(p.createdAt));
-      return age >= b.min && age < b.max;
-    }).length,
+    count: openAges.filter((age) => age >= b.min && age < b.max).length,
   }));
 
-  const oldestOpenDays =
-    openPrs.length === 0 ? null : Math.max(...openPrs.map((p) => daysBetween(now, instantFromString(p.createdAt))));
+  const oldestOpenDays = openAges.length === 0 ? null : Math.max(...openAges);
+  const openAvgAgeDays =
+    openAges.length === 0 ? null : Math.round(openAges.reduce((sum, age) => sum + age, 0) / openAges.length);
 
   const bumpCounts = new Map<string, number>();
   for (const pr of prs) {
@@ -300,6 +299,7 @@ function buildPrBacklog(data: CollectedData, now: Instant, windowStart: Instant)
     mergedInWindowCount: mergedInWindow.length,
     openAgeBuckets,
     oldestOpenDays,
+    openAvgAgeDays,
     bumpTypeSplit,
     devOnlyShare,
     ciStatusMix: { green, failing, pending },

src/report/costFormulas.ts

@@ -2,8 +2,8 @@
 // React app. No Temporal, no Bun globals, no React — keep this module dependency-free
 // so it bundles cleanly into both targets.
 
-export const ASSUMED_HOURLY_RATE_USD = 150;
-export const ASSUMED_MIN_PER_PR = 5;
+export const ASSUMED_HOURLY_RATE_USD = 200;
+export const ASSUMED_MIN_PER_PR = 12;
 
 export const AUTO_MERGE_SCENARIO_RATES = [0.5, 0.6, 0.7, 0.8] as const;
 

src/report/testFactories.ts

@@ -11,6 +11,7 @@ import type {
   ReportMeta,
   StalledSignals,
 } from './aggregate.ts';
+import { ASSUMED_HOURLY_RATE_USD, ASSUMED_MIN_PER_PR, deriveCostEstimate, derivePersonCosts } from './costFormulas.ts';
 import { type EmbeddedReportData, toEmbeddedShape } from './embeddedShape.ts';
 import type { ReportAnalyticsConfig } from './reportAnalyticsConfig.ts';
 
@@ -56,10 +57,10 @@ export const prBacklog = Factory.define<PrBacklog>(() => ({
     { label: '0–30 days', count: 40 },
     { label: '30–60 days', count: 18 },
     { label: '60–90 days', count: 6 },
-    { label: '90–180 days', count: 25 },
-    { label: '180+ days', count: 13 },
+    { label: '90+ days', count: 38 },
   ],
   oldestOpenDays: 312,
+  openAvgAgeDays: 74,
   bumpTypeSplit: [
     { bumpType: 'patch', count: 150, percentage: 55 },
     { bumpType: 'minor', count: 95, percentage: 34.8 },
@@ -77,31 +78,42 @@ export const stalledSignals = Factory.define<StalledSignals>(() => ({
   reposWithConfigButNoRecentPrs: ['acme/old-tool'],
 }));
 
+// Cost figures derive from the real defaults and formulas so the fixtures track
+// production whenever the assumptions move, rather than restating stale literals.
+const COST_WINDOW_DAYS = 90;
+const HUMAN_MERGE_COUNT = 150;
+const HUMAN_REVIEW_COUNT = 12;
+
 export const people = Factory.define<People>(() => ({
-  mergers: [
-    { login: 'alice', count: 90, windowCostUsd: 1125, annualCostUsd: 4563 },
-    { login: 'bob', count: 60, windowCostUsd: 750, annualCostUsd: 3042 },
-  ],
-  reviewers: [{ login: 'alice', count: 12, windowCostUsd: 90, annualCostUsd: 365 }],
+  mergers: derivePersonCosts(
+    [
+      { login: 'alice', count: 90 },
+      { login: 'bob', count: 60 },
+    ],
+    COST_WINDOW_DAYS,
+    ASSUMED_MIN_PER_PR,
+    ASSUMED_HOURLY_RATE_USD,
+  ),
+  reviewers: derivePersonCosts(
+    [{ login: 'alice', count: 12 }],
+    COST_WINDOW_DAYS,
+    ASSUMED_MIN_PER_PR,
+    ASSUMED_HOURLY_RATE_USD,
+  ),
   commenters: [],
 }));
 
 export const costEstimate = Factory.define<CostEstimate>(() => ({
-  humanMergeCount: 150,
-  humanReviewCount: 12,
+  humanMergeCount: HUMAN_MERGE_COUNT,
+  humanReviewCount: HUMAN_REVIEW_COUNT,
   openCount: 102,
-  windowDays: 90,
-  hourlyRateUsd: 150,
-  minutesPerPr: 5,
-  windowCostUsd: 2025,
-  monthlyCostUsd: 684,
-  annualCostUsd: 8208,
-  savingsScenarios: [
-    { autoMergeRate: 0.5, monthlySavingsUsd: 342, annualSavingsUsd: 4104 },
-    { autoMergeRate: 0.6, monthlySavingsUsd: 410, annualSavingsUsd: 4920 },
-    { autoMergeRate: 0.7, monthlySavingsUsd: 479, annualSavingsUsd: 5748 },
-    { autoMergeRate: 0.8, monthlySavingsUsd: 547, annualSavingsUsd: 6564 },
-  ],
+  windowDays: COST_WINDOW_DAYS,
+  hourlyRateUsd: ASSUMED_HOURLY_RATE_USD,
+  minutesPerPr: ASSUMED_MIN_PER_PR,
+  ...deriveCostEstimate(HUMAN_MERGE_COUNT + HUMAN_REVIEW_COUNT, COST_WINDOW_DAYS, {
+    hourlyRateUsd: ASSUMED_HOURLY_RATE_USD,
+    minutesPerPr: ASSUMED_MIN_PER_PR,
+  }),
 }));
 
 export const cveExposureOk = Factory.define<CveExposure>(() => ({