Fix new ads excluded by the 100-creative serving limit

lib/ads/candidates.ts

@@ -0,0 +1,32 @@
+import type { SupabaseClient } from "@supabase/supabase-js";
+import type { AdFormatId } from "./creative";
+
+// A page size, never a cap on the auction. The old LIMIT 100 excluded newer
+// campaigns entirely once a format had more than 100 ready creatives.
+const PAGE_SIZE = 500;
+const COLUMNS = "id, campaign_id, format, headline, body, cta_text, image_url, logo_url, bg_color, fg_color, accent_color, light_bg_color, light_fg_color, light_accent_color, font_family, ad_campaigns!inner(id, owner_id, status, ref_slug, destination_url, daily_budget_cents, spend_today_cents, spend_date, bid_credits)";
+
+export async function loadServingCreatives(sb: SupabaseClient, format: AdFormatId) {
+  const rows = [];
+  let after: string | undefined;
+  for (;;) {
+    let query = sb.from("ad_creatives")
+      .select(COLUMNS)
+      .eq("format", format)
+      .eq("status", "ready")
+      .in("ad_campaigns.status", ["active", "exhausted"])
+      .order("id", { ascending: true })
+      .limit(PAGE_SIZE);
+    if (after) query = query.gt("id", after);
+    const { data, error } = await query;
+    if (error) {
+      // Never run an auction against a silently incomplete candidate pool.
+      console.error("[ads] creative inventory unavailable", error.message);
+      return [];
+    }
+    if (!data?.length) return rows;
+    rows.push(...data);
+    if (data.length < PAGE_SIZE) return rows;
+    after = data[data.length - 1].id as string;
+  }
+}

lib/ads/serve.ts

@@ -1,4 +1,5 @@
 import crypto from "node:crypto";
+import { loadServingCreatives } from "./candidates";
 import { serviceClient } from "@/lib/supabase/service";
 import { env } from "@/lib/env";
 import {
@@ -221,15 +222,7 @@ export async function serveAd(
   // Campaigns with a ready creative in this format. 'exhausted' is a legacy
   // status no longer written by ad_charge_click — rows still carrying it are
   // live campaigns that ran dry, and belong on the free tier rather than dark.
-  const { data: creatives } = await sb
-    .from("ad_creatives")
-    .select(
-      "id, campaign_id, format, headline, body, cta_text, image_url, logo_url, bg_color, fg_color, accent_color, light_bg_color, light_fg_color, light_accent_color, font_family, ad_campaigns!inner(id, owner_id, status, ref_slug, destination_url, daily_budget_cents, spend_today_cents, spend_date, bid_credits)",
-    )
-    .eq("format", format)
-    .eq("status", "ready")
-    .in("ad_campaigns.status", ["active", "exhausted"])
-    .limit(100);
+  const creatives = await loadServingCreatives(sb, format);
 
   // No paid creative for this format → default CrawlProof house ad.
   if (!creatives || creatives.length === 0) return houseFill(format, theme);

tests/contract/ads-self-deal.test.ts

@@ -1,4 +1,4 @@
-import { beforeEach, describe, expect, it, vi } from "vitest";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 // Regression: a self-owned campaign (same profile owns the slot and the
 // campaign) used to be filtered out of the candidate list entirely. That is
@@ -22,6 +22,7 @@ const H = vi.hoisted(() => {
       slotOwner: OWNER as string | null,
       campaignOwners: [OWNER] as string[],
       credits: 9999,
+      inventoryErrorAfter: false,
       inserted: [] as Record<string, unknown>[],
     },
   };
@@ -87,10 +88,26 @@ vi.mock("@/lib/supabase/service", () => ({
         });
       }
       if (table === "ad_creatives") {
-        return chain({
-          data: state.campaignOwners.map((o, i) => creativeFor(o, i)),
-          error: null,
+        let limit = 1000; // PostgREST's default response cap.
+        let after = "";
+        const query: unknown = new Proxy({}, {
+          get(_target, prop) {
+            if (prop === "then") {
+              const rows = state.campaignOwners.map((o, i) => creativeFor(o, i))
+                .sort((a, b) => a.id.localeCompare(b.id))
+                .filter((r) => r.id > after).slice(0, limit);
+              const result = after && state.inventoryErrorAfter
+                ? { data: null, error: { message: "inventory timeout" } }
+                : { data: rows, error: null };
+              const promise = Promise.resolve(result);
+              return promise.then.bind(promise);
+            }
+            if (prop === "limit") return (n: number) => { limit = n; return query; };
+            if (prop === "gt") return (_key: string, id: string) => { after = id; return query; };
+            return () => query;
+          },
         });
+        return query;
       }
       if (table === "profiles") {
         return chain({
@@ -187,3 +204,39 @@ describe("self-deal still loses to a real advertiser", () => {
     expect(state.inserted.some((r) => r.tier === "paid")).toBe(true);
   });
 });
+
+
+describe("inventory beyond the first page", () => {
+  afterEach(() => { vi.restoreAllMocks(); state.inventoryErrorAfter = false; });
+
+  it.each([374, 500, 1201])("allows the last of %i campaigns to win and records its impression", async (count) => {
+    vi.resetModules();
+    state.slotOwner = OWNER;
+    state.campaignOwners = Array(count).fill(OWNER);
+    state.credits = 9999;
+    state.inserted = [];
+    // Select the last candidate in the ordered pool, past both the former
+    // 100-row cutoff and (in the larger fixture) PostgREST's 1000-row cap.
+    vi.spyOn(Math, "random").mockReturnValue(0.999999);
+    const last = state.campaignOwners.map((owner, i) => creativeFor(owner, i))
+      .sort((a, b) => a.id.localeCompare(b.id)).at(-1)!;
+    const fill = await serve();
+    expect(fill?.campaignId).toBe(last.campaign_id);
+    expect(fill?.tier).toBe("free");
+    expect(state.inserted).toEqual([expect.objectContaining({ campaign_id: last.campaign_id })]);
+  });
+
+  it("does not auction a partial pool when a later inventory page fails", async () => {
+    vi.resetModules();
+    state.slotOwner = OWNER;
+    state.campaignOwners = Array(501).fill(OWNER);
+    state.inventoryErrorAfter = true;
+    state.inserted = [];
+    const log = vi.spyOn(console, "error").mockImplementation(() => {});
+    const fill = await serve();
+    expect(fill?.campaignId).toBe("house");
+    expect(state.inserted).toEqual([]);
+    expect(log).toHaveBeenCalledWith("[ads] creative inventory unavailable", "inventory timeout");
+  });
+
+});