From f212be8d830cc3dcaf8cad0d37650ca4cf0b7ac6 Mon Sep 17 00:00:00 2001
From: dhgoal <153369624+dhgoal@users.noreply.github.com>
Date: Sun, 12 Jul 2026 21:15:13 +0900
Subject: [PATCH] feat(analytics): add slop + duplicate signal to the
 maintainer quality dashboard (#2202)

Fold a slop + duplicate aggregate into MaintainerQualityDashboard: how many of
the maintainer's open PRs carry an elevated/high deterministic slop band and
how many sit in a high-risk duplicate cluster, each as a rate of the open-PR
total (null when there are no open PRs, guarding the divide). Pure in-memory
aggregation over data the shaping loop already produces (no new IO). Adds
SlopDuplicateCard rendering the two rates with proportional bars + low/watch/
high bands, wired into MaintainerPanel; empty states for a clear queue and an
absent field. Current-window rates; a time-series trend is a follow-up.
---
 .../site/app-panels/maintainer-panel.tsx      |   7 ++
 .../app-panels/slop-duplicate-card.test.tsx   |  63 ++++++++++
 .../site/app-panels/slop-duplicate-card.tsx   | 109 ++++++++++++++++++
 src/services/maintainer-quality-dashboard.ts  |  20 ++++
 .../unit/maintainer-quality-dashboard.test.ts |  20 ++++
 5 files changed, 219 insertions(+)
 create mode 100644 apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.test.tsx
 create mode 100644 apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.tsx

diff --git a/apps/gittensory-ui/src/components/site/app-panels/maintainer-panel.tsx b/apps/gittensory-ui/src/components/site/app-panels/maintainer-panel.tsx
index d81b50e5f..89970c86c 100644
--- a/apps/gittensory-ui/src/components/site/app-panels/maintainer-panel.tsx
+++ b/apps/gittensory-ui/src/components/site/app-panels/maintainer-panel.tsx
@@ -27,6 +27,10 @@ import {
   QueueHealthCard,
   type MaintainerQueueHealth,
 } from "@/components/site/app-panels/queue-health-card";
+import {
+  SlopDuplicateCard,
+  type SlopDuplicateSignal,
+} from "@/components/site/app-panels/slop-duplicate-card";
 import { MaintainerSettings } from "@/components/site/app-panels/maintainer-settings";
 import { OnboardingPreviewCard } from "@/components/site/app-panels/onboarding-preview-card";
 import { CheckRunReadinessTable } from "@/components/site/check-run-readiness-table";
@@ -92,6 +96,7 @@ type MaintainerDashboard = {
     topContributors: MaintainerTopContributor[];
     gateOutcomeBreakdown: GateOutcomeCardData;
     queueHealth?: MaintainerQueueHealth;
+    slopDuplicate?: SlopDuplicateSignal;
   };
 };
 
@@ -388,6 +393,8 @@ function MaintainerDashboardView({
 
           <QueueHealthCard queueHealth={data.qualityDashboard.queueHealth} />
 
+          <SlopDuplicateCard signal={data.qualityDashboard.slopDuplicate} />
+
           <ContributorQualityTable topContributors={data.qualityDashboard.topContributors} />
 
           <ActivationPreview reviewability={data.reviewability} />
diff --git a/apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.test.tsx b/apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.test.tsx
new file mode 100644
index 000000000..09d44c491
--- /dev/null
+++ b/apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.test.tsx
@@ -0,0 +1,63 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it } from "vitest";
+
+import { SlopDuplicateCard } from "@/components/site/app-panels/slop-duplicate-card";
+
+describe("SlopDuplicateCard", () => {
+  it("renders both signal rows with rates and flagged/total counts when populated", () => {
+    render(
+      <SlopDuplicateCard
+        signal={{
+          openPullRequests: 20,
+          slopFlaggedPullRequests: 3,
+          duplicateFlaggedPullRequests: 8,
+          slopRate: 0.15,
+          duplicateRate: 0.4,
+        }}
+      />,
+    );
+    expect(screen.getByText("Slop-flagged")).toBeTruthy();
+    expect(screen.getByText("Duplicate-flagged")).toBeTruthy();
+    expect(screen.getByText("15%")).toBeTruthy();
+    expect(screen.getByText("40%")).toBeTruthy();
+    expect(screen.getByText(/3 of 20 open PRs/)).toBeTruthy();
+    expect(screen.getByText(/8 of 20 open PRs/)).toBeTruthy();
+  });
+
+  it("renders an em-dash when a rate is null (unassessed)", () => {
+    render(
+      <SlopDuplicateCard
+        signal={{
+          openPullRequests: 5,
+          slopFlaggedPullRequests: 0,
+          duplicateFlaggedPullRequests: 1,
+          slopRate: null,
+          duplicateRate: 0.2,
+        }}
+      />,
+    );
+    expect(screen.getByText("—")).toBeTruthy();
+    expect(screen.getByText("no data")).toBeTruthy();
+  });
+
+  it("shows the 'queue is clear' empty state when there are no open PRs", () => {
+    render(
+      <SlopDuplicateCard
+        signal={{
+          openPullRequests: 0,
+          slopFlaggedPullRequests: 0,
+          duplicateFlaggedPullRequests: 0,
+          slopRate: null,
+          duplicateRate: null,
+        }}
+      />,
+    );
+    expect(screen.getByText("Queue is clear")).toBeTruthy();
+    expect(screen.queryByText("Slop-flagged")).toBeNull();
+  });
+
+  it("shows the 'not yet available' empty state when the signal is absent", () => {
+    render(<SlopDuplicateCard />);
+    expect(screen.getByText("Not yet available")).toBeTruthy();
+  });
+});
diff --git a/apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.tsx b/apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.tsx
new file mode 100644
index 000000000..0e154ae90
--- /dev/null
+++ b/apps/gittensory-ui/src/components/site/app-panels/slop-duplicate-card.tsx
@@ -0,0 +1,109 @@
+import { AnalyticsCardShell } from "@/components/site/app-panels/analytics-card-shell";
+import { StatusPill, type Status } from "@/components/site/control-primitives";
+import { cn } from "@/lib/utils";
+
+/** Aggregate slop + duplicate signal for the maintainer quality dashboard (#2202): the share of the maintainer's
+ *  open PRs carrying an elevated/high deterministic slop band and the share sitting in a high-risk duplicate
+ *  cluster, each as a rate of the open-PR total. Display slice over the dashboard payload's `slopDuplicate`
+ *  aggregate — observable rates + bands, never raw scores. Degrades to an empty state when the queue is clear
+ *  or the field is absent. (Current-window rates; a time-series trend is a follow-up per the issue thread.) */
+export type SlopDuplicateSignal = {
+  openPullRequests: number;
+  slopFlaggedPullRequests: number;
+  duplicateFlaggedPullRequests: number;
+  slopRate: number | null;
+  duplicateRate: number | null;
+};
+
+/** Lower is healthier — a small flagged share is good; a large one is a burden signal. */
+function rateStatus(rate: number | null): Status {
+  if (rate === null) return "info";
+  if (rate < 0.1) return "ready";
+  if (rate < 0.3) return "warn";
+  return "degraded";
+}
+
+function rateBandLabel(rate: number | null): string {
+  if (rate === null) return "no data";
+  if (rate < 0.1) return "low";
+  if (rate < 0.3) return "watch";
+  return "high";
+}
+
+function SignalRow({
+  label,
+  rate,
+  flagged,
+  total,
+  bar,
+}: {
+  label: string;
+  rate: number | null;
+  flagged: number;
+  total: number;
+  bar: string;
+}) {
+  const pct = rate === null ? null : Math.round(rate * 100);
+  return (
+    <div className="space-y-1.5">
+      <div className="flex items-center justify-between gap-3 text-token-sm">
+        <span className="font-medium text-foreground">{label}</span>
+        <span className="font-mono text-token-xs text-muted-foreground">
+          {pct === null ? "—" : `${pct}%`}
+        </span>
+      </div>
+      <div className="h-2 overflow-hidden rounded-full bg-border" aria-hidden>
+        {pct === null ? null : <div className={cn("h-full", bar)} style={{ width: `${pct}%` }} />}
+      </div>
+      <div className="flex items-center justify-between font-mono text-token-2xs text-muted-foreground">
+        <span>
+          {flagged} of {total} open PR{total === 1 ? "" : "s"}
+        </span>
+        <StatusPill status={rateStatus(rate)}>{rateBandLabel(rate)}</StatusPill>
+      </div>
+    </div>
+  );
+}
+
+export function SlopDuplicateCard({ signal }: { signal?: SlopDuplicateSignal }) {
+  if (!signal || signal.openPullRequests === 0) {
+    return (
+      <AnalyticsCardShell
+        title="Slop & duplicate signal"
+        description="Share of open PRs flagged as slop or in a high-risk duplicate cluster, across your repos."
+        state="empty"
+        emptyTitle={signal ? "Queue is clear" : "Not yet available"}
+        emptyHint={
+          signal
+            ? "No open pull requests across the shaped repos in this window."
+            : "The slop + duplicate signal appears once the maintainer dashboard payload includes the aggregate."
+        }
+      />
+    );
+  }
+
+  return (
+    <AnalyticsCardShell
+      title="Slop & duplicate signal"
+      description="Share of open PRs flagged as slop or in a high-risk duplicate cluster, across your repos."
+      state="ready"
+    >
+      <div className="space-y-4">
+        <SignalRow
+          label="Slop-flagged"
+          rate={signal.slopRate}
+          flagged={signal.slopFlaggedPullRequests}
+          total={signal.openPullRequests}
+          bar="bg-warning"
+        />
+        <SignalRow
+          label="Duplicate-flagged"
+          rate={signal.duplicateRate}
+          flagged={signal.duplicateFlaggedPullRequests}
+          total={signal.openPullRequests}
+          bar="bg-danger"
+        />
+      </div>
+    </AnalyticsCardShell>
+  );
+}
diff --git a/src/services/maintainer-quality-dashboard.ts b/src/services/maintainer-quality-dashboard.ts
index bfc171ca1..8336f88f5 100644
--- a/src/services/maintainer-quality-dashboard.ts
+++ b/src/services/maintainer-quality-dashboard.ts
@@ -58,6 +58,16 @@ export type MaintainerQualityDashboard = {
     ageBuckets: { under7Days: number; days7To30: number; over30Days: number };
     bandCounts: Record<QueueHealth["level"], number>;
   };
+  /** Aggregate slop + duplicate signal across the SHAPED repos' open PRs (#2202): how many open PRs carry an
+   *  elevated/high deterministic slop band, how many sit in a high-risk duplicate cluster, and each as a rate
+   *  of the open-PR total (null when there are no open PRs). Observable counts + rates, never raw scores. */
+  slopDuplicate: {
+    openPullRequests: number;
+    slopFlaggedPullRequests: number;
+    duplicateFlaggedPullRequests: number;
+    slopRate: number | null;
+    duplicateRate: number | null;
+  };
   summary: string;
 };
 
@@ -91,6 +101,7 @@ export function buildMaintainerQualityDashboard(args: { repos: MaintainerQuality
   let openPrs = 0;
   let duplicatePrRisk = 0;
   let missingLinkedIssue = 0;
+  let slopFlaggedPrs = 0;
   const queueHealthAggregate = {
     openPullRequests: 0,
     stalePullRequests: 0,
@@ -141,6 +152,8 @@ export function buildMaintainerQualityDashboard(args: { repos: MaintainerQuality
       const inHighRiskCluster = highRiskPrNumbers.has(pr.number);
       if (pr.linkedIssues.length === 0) missingLinkedIssue += 1;
       if (inHighRiskCluster) duplicatePrRisk += 1;
+      // #2202: an "elevated" or "high" deterministic slop band is the slop flag (null/absent = not assessed).
+      if (pr.slopBand === "elevated" || pr.slopBand === "high") slopFlaggedPrs += 1;
       const linkedToRealIssue = pr.linkedIssues.some((number) => realIssueNumbers.has(number));
       const author = pr.authorLogin ?? "unknown";
       const tally = contributorTotals.get(author) ?? { open: 0, clean: 0 };
@@ -171,6 +184,13 @@ export function buildMaintainerQualityDashboard(args: { repos: MaintainerQuality
     topContributors,
     qualitySignals: { openPrs, duplicatePrRisk, missingLinkedIssue },
     queueHealth: queueHealthAggregate,
+    slopDuplicate: {
+      openPullRequests: openPrs,
+      slopFlaggedPullRequests: slopFlaggedPrs,
+      duplicateFlaggedPullRequests: duplicatePrRisk,
+      slopRate: openPrs > 0 ? slopFlaggedPrs / openPrs : null,
+      duplicateRate: openPrs > 0 ? duplicatePrRisk / openPrs : null,
+    },
     summary,
   };
 }
diff --git a/test/unit/maintainer-quality-dashboard.test.ts b/test/unit/maintainer-quality-dashboard.test.ts
index b9ced8cf6..36f3aff8a 100644
--- a/test/unit/maintainer-quality-dashboard.test.ts
+++ b/test/unit/maintainer-quality-dashboard.test.ts
@@ -68,6 +68,26 @@ describe("buildMaintainerQualityDashboard", () => {
     expect(JSON.stringify(dashboard)).not.toMatch(/"burdenScore"/);
   });
 
+  it("aggregates the slop + duplicate signal and its rates, failing safe to null rates with no open PRs (#2202)", () => {
+    const flagged = buildMaintainerQualityDashboard({
+      repos: [input({ pullRequests: [pr(1), pr(2, { slopBand: "high" })] })],
+      generatedAt: "2026-06-14T00:00:00.000Z",
+    });
+    expect(flagged.slopDuplicate.openPullRequests).toBe(2);
+    expect(flagged.slopDuplicate.slopFlaggedPullRequests).toBe(1);
+    expect(flagged.slopDuplicate.slopRate).toBeCloseTo(0.5);
+    expect(flagged.slopDuplicate.duplicateRate).not.toBeNull();
+
+    // No open PRs → the rates divide-guard to null rather than 0/0.
+    const empty = buildMaintainerQualityDashboard({
+      repos: [input({ pullRequests: [] })],
+      generatedAt: "2026-06-14T00:00:00.000Z",
+    });
+    expect(empty.slopDuplicate.openPullRequests).toBe(0);
+    expect(empty.slopDuplicate.slopRate).toBeNull();
+    expect(empty.slopDuplicate.duplicateRate).toBeNull();
+  });
+
   it("counts PRs without a linked issue toward the missing-linked-issue signal", () => {
     const dashboard = buildMaintainerQualityDashboard({
       repos: [input({ pullRequests: [pr(1, { linkedIssues: [] }), pr(2, { linkedIssues: [5] })] })],