fix(public-stats): redact sparse accuracy trend counts

apps/gittensory-ui/public/openapi.json

@@ -474,13 +474,16 @@
                   "type": "string"
                 },
                 "merged": {
-                  "type": "number"
+                  "type": "number",
+                  "nullable": true
                 },
                 "closed": {
-                  "type": "number"
+                  "type": "number",
+                  "nullable": true
                 },
                 "reversed": {
-                  "type": "number"
+                  "type": "number",
+                  "nullable": true
                 },
                 "accuracyPct": {
                   "type": "number",

src/openapi/schemas.ts

@@ -120,14 +120,14 @@ export const PublicStatsSchema = z
         accuracyPct: z.number().nullable(),
       }),
     ),
-    /** Trailing weekly history of totals.accuracyPct's SAME formula (#4447) -- null accuracyPct on a week means
-     *  too few decided (merged+closed) PRs that week to publish a meaningful percentage, not zero accuracy. */
+    /** Trailing weekly history of totals.accuracyPct's SAME formula (#4447) -- null counts/accuracyPct on a week means
+     *  too few decided (merged+closed) PRs to publish meaningful or non-identifying details. */
     accuracyTrend: z.array(
       z.object({
         weekStart: z.string(),
-        merged: z.number(),
-        closed: z.number(),
-        reversed: z.number(),
+        merged: z.number().nullable(),
+        closed: z.number().nullable(),
+        reversed: z.number().nullable(),
         accuracyPct: z.number().nullable(),
       }),
     ),

src/services/public-accuracy-trend.ts

@@ -18,9 +18,9 @@ export const MIN_ACCURACY_TREND_SAMPLE = 3;
 export type PublicAccuracyTrendWeek = {
   /** UTC Monday (YYYY-MM-DD) that starts the bucket. */
   weekStart: string;
-  merged: number;
-  closed: number;
-  reversed: number;
+  merged: number | null;
+  closed: number | null;
+  reversed: number | null;
   accuracyPct: number | null;
 };
 
@@ -34,11 +34,11 @@ function roundPct(value: number): number {
 
 /** Same formula as public-stats.ts's accuracyPct, reused so the trend and the live number can never drift
  *  apart into two competing definitions of "accuracy". */
-function accuracyPctOf(merged: number, closed: number, reversed: number): number | null {
-  const decided = merged + closed;
-  if (decided < MIN_ACCURACY_TREND_SAMPLE) return null;
-  const reversalRate = Math.min(1, reversed / decided);
-  return roundPct(1 - reversalRate);
+function publicBucketOf(bucket: { merged: number; closed: number; reversed: number }): Omit<PublicAccuracyTrendWeek, "weekStart"> {
+  const decided = bucket.merged + bucket.closed;
+  if (decided < MIN_ACCURACY_TREND_SAMPLE) return { merged: null, closed: null, reversed: null, accuracyPct: null };
+  const reversalRate = Math.min(1, bucket.reversed / decided);
+  return { merged: bucket.merged, closed: bucket.closed, reversed: bucket.reversed, accuracyPct: roundPct(1 - reversalRate) };
 }
 
 /** Fold day-granularity rows into `weeks` trailing UTC-Monday buckets ending in the week containing `nowMs`.
@@ -61,10 +61,7 @@ export function buildPublicAccuracyTrend(dayRows: DayRow[], nowMs: number, weeks
 
   return buckets.map((bucket, offset) => ({
     weekStart: isoWeekStart(oldestStartMs + offset * MS_PER_WEEK),
-    merged: bucket.merged,
-    closed: bucket.closed,
-    reversed: bucket.reversed,
-    accuracyPct: accuracyPctOf(bucket.merged, bucket.closed, bucket.reversed),
+    ...publicBucketOf(bucket),
   }));
 }
 

test/integration/public-stats-route.test.ts

@@ -63,7 +63,7 @@ describe("GET /v1/public/stats (#1059)", () => {
       totals: Record<string, number | null>;
       weekly: { reviewed: number; merged: number };
       byProject: Array<{ project: string; reviewed: number }>;
-      accuracyTrend: Array<{ weekStart: string; merged: number; closed: number; reversed: number; accuracyPct: number | null }>;
+      accuracyTrend: Array<{ weekStart: string; merged: number | null; closed: number | null; reversed: number | null; accuracyPct: number | null }>;
       reuseRateTrend: Array<{ weekStart: string; hits: number; misses: number; reuseRatePct: number | null }>;
       reviewVolumeTrend: Array<{ weekStart: string; reviewed: number; merged: number; filteredPct: number | null }>;
     };

test/unit/public-accuracy-trend.test.ts

@@ -45,22 +45,22 @@ describe("buildPublicAccuracyTrend", () => {
   it("REGRESSION: ignores day rows outside the trailing window instead of letting them corrupt the oldest bucket", () => {
     const currentMonday = isoWeekStart(NOW);
     const tooOld = isoWeekStart(NOW - 30 * 86_400_000);
-    const trend = buildPublicAccuracyTrend([{ day: tooOld, merged: 999, closed: 999, reversed: 999 }, { day: currentMonday, merged: 1, closed: 0, reversed: 0 }], NOW, 2);
-    expect(trend[0]).toMatchObject({ merged: 0, closed: 0, reversed: 0 });
-    expect(trend[1]).toMatchObject({ merged: 1, closed: 0, reversed: 0 });
+    const trend = buildPublicAccuracyTrend([{ day: tooOld, merged: 999, closed: 999, reversed: 999 }, { day: currentMonday, merged: MIN_ACCURACY_TREND_SAMPLE, closed: 0, reversed: 0 }], NOW, 2);
+    expect(trend[0]).toMatchObject({ merged: null, closed: null, reversed: null });
+    expect(trend[1]).toMatchObject({ merged: MIN_ACCURACY_TREND_SAMPLE, closed: 0, reversed: 0 });
   });
 
   it("ignores an unparseable day string rather than throwing or corrupting a bucket", () => {
     const currentMonday = isoWeekStart(NOW);
-    const trend = buildPublicAccuracyTrend([{ day: "not-a-date", merged: 5, closed: 5, reversed: 5 }, { day: currentMonday, merged: 1, closed: 0, reversed: 0 }], NOW, 1);
+    const trend = buildPublicAccuracyTrend([{ day: "not-a-date", merged: 5, closed: 5, reversed: 5 }, { day: currentMonday, merged: MIN_ACCURACY_TREND_SAMPLE, closed: 0, reversed: 0 }], NOW, 1);
     expect(trend).toHaveLength(1);
-    expect(trend[0]).toMatchObject({ merged: 1, closed: 0, reversed: 0 });
+    expect(trend[0]).toMatchObject({ merged: MIN_ACCURACY_TREND_SAMPLE, closed: 0, reversed: 0 });
   });
 
-  it("returns null accuracyPct (not a misleading 0% or 100%) below MIN_ACCURACY_TREND_SAMPLE decided PRs", () => {
+  it("REGRESSION: redacts counts and accuracyPct below MIN_ACCURACY_TREND_SAMPLE decided PRs", () => {
     const week = isoWeekStart(NOW);
     const trend = buildPublicAccuracyTrend([{ day: week, merged: MIN_ACCURACY_TREND_SAMPLE - 1, closed: 0, reversed: 0 }], NOW, 1);
-    expect(trend[0]?.accuracyPct).toBeNull();
+    expect(trend[0]).toMatchObject({ merged: null, closed: null, reversed: null, accuracyPct: null });
   });
 
   it("returns a real percentage at exactly MIN_ACCURACY_TREND_SAMPLE decided PRs", () => {
@@ -83,7 +83,7 @@ describe("buildPublicAccuracyTrend", () => {
   it("returns all-zero, null-accuracy buckets for an empty input (a brand-new / not-yet-enabled deployment)", () => {
     const trend = buildPublicAccuracyTrend([], NOW, 3);
     expect(trend).toHaveLength(3);
-    for (const week of trend) expect(week).toMatchObject({ merged: 0, closed: 0, reversed: 0, accuracyPct: null });
+    for (const week of trend) expect(week).toMatchObject({ merged: null, closed: null, reversed: null, accuracyPct: null });
   });
 });
 
@@ -130,7 +130,7 @@ describe("loadPublicAccuracyTrend — end-to-end over the real live tables", ()
     expect(currentWeek?.reversed).toBe(1);
   });
 
-  it("still reports the Orb-fleet side when GITTENSORY_PUBLIC_STATS_REPOS is empty (no own-ledger allowlist)", async () => {
+  it("redacts a sparse Orb-fleet week when GITTENSORY_PUBLIC_STATS_REPOS is empty (no own-ledger allowlist)", async () => {
     const env = createTestEnv({ GITTENSORY_PUBLIC_STATS_REPOS: "" });
     const thisMonday = isoWeekStart(NOW);
     const thisWeekIso = `${thisMonday}T09:00:00.000Z`;
@@ -141,8 +141,6 @@ describe("loadPublicAccuracyTrend — end-to-end over the real live tables", ()
 
     const trend = await loadPublicAccuracyTrend(env, NOW);
     const currentWeek = trend[trend.length - 1];
-    expect(currentWeek?.closed).toBe(1);
-    expect(currentWeek?.merged).toBe(0);
-    expect(currentWeek?.reversed).toBe(0);
+    expect(currentWeek).toMatchObject({ merged: null, closed: null, reversed: null, accuracyPct: null });
   });
 });