better cache

2026-02-10 01:20:58 -05:00
parent c773affbc8
commit f056e67eae
39 changed files with 830 additions and 17 deletions
--- a/site/.env.example
+++ b/site/.env.example
@@ -19,3 +19,17 @@ WORDPRESS_BASE_URL=
 # Optional credentials (prefer an Application Password). Leave blank if your WP endpoints are public.
 WORDPRESS_USERNAME=
 WORDPRESS_APP_PASSWORD=
+
+# Cache layer (optional; used by ingestion scripts)
+# If unset, caching is disabled.
+#
+# Using docker-compose redis:
+# CACHE_REDIS_URL=redis://localhost:6380/0
+CACHE_REDIS_URL=
+# Alternative config if you prefer host/port/db:
+CACHE_REDIS_HOST=localhost
+CACHE_REDIS_PORT=6380
+CACHE_REDIS_DB=0
+
+# Default cache TTL (seconds). 3600 = 1 hour.
+CACHE_DEFAULT_TTL_SECONDS=3600
--- a/site/content/cache/content.json
+++ b/site/content/cache/content.json
@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-02-10T06:01:51.379Z",
+  "generatedAt": "2026-02-10T06:16:26.031Z",
  "items": [
    {
      "id": "gPGbtfQdaw4",
@@ -31,7 +31,7 @@
      "publishedAt": "2026-02-05T04:31:18.000Z",
      "thumbnailUrl": "https://i.ytimg.com/vi/9t8cBpZLHUo/hqdefault.jpg",
      "metrics": {
-        "views": 328
+        "views": 325
      }
    },
    {
--- a/site/package-lock.json
+++ b/site/package-lock.json
@@ -10,6 +10,7 @@
      "dependencies": {
        "@astrojs/sitemap": "^3.7.0",
        "astro": "^5.17.1",
+        "redis": "^4.7.1",
        "rss-parser": "^3.13.0",
        "zod": "^3.25.76"
      },
@@ -1241,6 +1242,65 @@
      "integrity": "sha512-70wQhgYmndg4GCPxPPxPGevRKqTIJ2Nh4OkiMWmDAVYsTQ+Ta7Sq+rPevXyXGdzr30/qZBnyOalCszoMxlyldQ==",
      "license": "MIT"
    },
+    "node_modules/@redis/bloom": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/@redis/bloom/-/bloom-1.2.0.tgz",
+      "integrity": "sha512-HG2DFjYKbpNmVXsa0keLHp/3leGJz1mjh09f2RLGGLQZzSHpkmZWuwJbAvo3QcRY8p80m5+ZdXZdYOSBLlp7Cg==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@redis/client": "^1.0.0"
+      }
+    },
+    "node_modules/@redis/client": {
+      "version": "1.6.1",
+      "resolved": "https://registry.npmjs.org/@redis/client/-/client-1.6.1.tgz",
+      "integrity": "sha512-/KCsg3xSlR+nCK8/8ZYSknYxvXHwubJrU82F3Lm1Fp6789VQ0/3RJKfsmRXjqfaTA++23CvC3hqmqe/2GEt6Kw==",
+      "license": "MIT",
+      "dependencies": {
+        "cluster-key-slot": "1.1.2",
+        "generic-pool": "3.9.0",
+        "yallist": "4.0.0"
+      },
+      "engines": {
+        "node": ">=14"
+      }
+    },
+    "node_modules/@redis/graph": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/@redis/graph/-/graph-1.1.1.tgz",
+      "integrity": "sha512-FEMTcTHZozZciLRl6GiiIB4zGm5z5F3F6a6FZCyrfxdKOhFlGkiAqlexWMBzCi4DcRoyiOsuLfW+cjlGWyExOw==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@redis/client": "^1.0.0"
+      }
+    },
+    "node_modules/@redis/json": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/@redis/json/-/json-1.0.7.tgz",
+      "integrity": "sha512-6UyXfjVaTBTJtKNG4/9Z8PSpKE6XgSyEb8iwaqDcy+uKrd/DGYHTWkUdnQDyzm727V7p21WUMhsqz5oy65kPcQ==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@redis/client": "^1.0.0"
+      }
+    },
+    "node_modules/@redis/search": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/@redis/search/-/search-1.2.0.tgz",
+      "integrity": "sha512-tYoDBbtqOVigEDMAcTGsRlMycIIjwMCgD8eR2t0NANeQmgK/lvxNAvYyb6bZDD4frHRhIHkJu2TBRvB0ERkOmw==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@redis/client": "^1.0.0"
+      }
+    },
+    "node_modules/@redis/time-series": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/@redis/time-series/-/time-series-1.1.0.tgz",
+      "integrity": "sha512-c1Q99M5ljsIuc4YdaCwfUEXsofakb9c8+Zse2qxTadu8TalLXuAESzLvFAvNVbkmSlvlzIQOLpBCmWI9wTOt+g==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@redis/client": "^1.0.0"
+      }
+    },
    "node_modules/@rollup/pluginutils": {
      "version": "5.3.0",
      "resolved": "https://registry.npmjs.org/@rollup/pluginutils/-/pluginutils-5.3.0.tgz",
@@ -2515,6 +2575,15 @@
        "node": ">=6"
      }
    },
+    "node_modules/cluster-key-slot": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/cluster-key-slot/-/cluster-key-slot-1.1.2.tgz",
+      "integrity": "sha512-RMr0FhtfXemyinomL4hrWcYJxmX6deFdCxpJzhDttxgO1+bcCnkk+9drydLVDmAMG7NE6aN/fl4F7ucU/90gAA==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
    "node_modules/color-convert": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-2.0.1.tgz",
@@ -3090,6 +3159,15 @@
        "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
      }
    },
+    "node_modules/generic-pool": {
+      "version": "3.9.0",
+      "resolved": "https://registry.npmjs.org/generic-pool/-/generic-pool-3.9.0.tgz",
+      "integrity": "sha512-hymDOu5B53XvN4QT9dBmZxPX4CWhBPPLguTZ9MMFeFa/Kg0xWVfylOVNlJji/E7yTZWFd/q9GO5TxDLq156D7g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 4"
+      }
+    },
    "node_modules/get-caller-file": {
      "version": "2.0.5",
      "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
@@ -4687,6 +4765,23 @@
        "url": "https://paulmillr.com/funding/"
      }
    },
+    "node_modules/redis": {
+      "version": "4.7.1",
+      "resolved": "https://registry.npmjs.org/redis/-/redis-4.7.1.tgz",
+      "integrity": "sha512-S1bJDnqLftzHXHP8JsT5II/CtHWQrASX5K96REjWjlmWKrviSOLWmM7QnRLstAWsu1VBBV1ffV6DzCvxNP0UJQ==",
+      "license": "MIT",
+      "workspaces": [
+        "./packages/*"
+      ],
+      "dependencies": {
+        "@redis/bloom": "1.2.0",
+        "@redis/client": "1.6.1",
+        "@redis/graph": "1.1.1",
+        "@redis/json": "1.0.7",
+        "@redis/search": "1.2.0",
+        "@redis/time-series": "1.1.0"
+      }
+    },
    "node_modules/regex": {
      "version": "6.1.0",
      "resolved": "https://registry.npmjs.org/regex/-/regex-6.1.0.tgz",
@@ -6745,6 +6840,12 @@
        "node": ">=10"
      }
    },
+    "node_modules/yallist": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/yallist/-/yallist-4.0.0.tgz",
+      "integrity": "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A==",
+      "license": "ISC"
+    },
    "node_modules/yaml": {
      "version": "2.8.2",
      "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.8.2.tgz",
--- a/site/package.json
+++ b/site/package.json
@@ -7,6 +7,7 @@
    "build": "astro build",
    "preview": "astro preview",
    "fetch-content": "tsx scripts/fetch-content.ts",
+    "cache:clear": "tsx scripts/cache-clear.ts",
    "verify:blog": "npm run build && tsx scripts/verify-blog-build.ts",
    "typecheck": "astro check",
    "format": "prettier -w .",
@@ -17,6 +18,7 @@
  "dependencies": {
    "@astrojs/sitemap": "^3.7.0",
    "astro": "^5.17.1",
+    "redis": "^4.7.1",
    "rss-parser": "^3.13.0",
    "zod": "^3.25.76"
  },
--- a/site/scripts/cache-clear.ts
+++ b/site/scripts/cache-clear.ts
@@ -0,0 +1,22 @@
+import "dotenv/config";
+
+import { createCacheFromEnv } from "../src/lib/cache";
+
+function log(msg: string) {
+  // eslint-disable-next-line no-console
+  console.log(`[cache-clear] ${msg}`);
+}
+
+async function main() {
+  const cache = await createCacheFromEnv(process.env, { namespace: "fast-website", log });
+  await cache.flush();
+  await cache.close();
+  log("ok");
+}
+
+main().catch((e) => {
+  // eslint-disable-next-line no-console
+  console.error(`[cache-clear] failed: ${String(e)}`);
+  process.exitCode = 1;
+});
+
--- a/site/scripts/fetch-content.ts
+++ b/site/scripts/fetch-content.ts
@@ -4,6 +4,8 @@ import { promises as fs } from "node:fs";
 import path from "node:path";

 import { getIngestConfigFromEnv } from "../src/lib/config";
+import { createCacheFromEnv } from "../src/lib/cache";
+import { cachedCompute } from "../src/lib/cache/memoize";
 import type { ContentCache, ContentItem } from "../src/lib/content/types";
 import { readInstagramEmbedPosts } from "../src/lib/ingest/instagram";
 import { fetchPodcastRss } from "../src/lib/ingest/podcast";
@@ -42,6 +44,11 @@ async function main() {
  const all: ContentItem[] = [];
  const outPath = path.join(process.cwd(), "content", "cache", "content.json");

+  const kv = await createCacheFromEnv(process.env, {
+    namespace: "fast-website",
+    log,
+  });
+
  // Read the existing cache so we can keep last-known-good sections if a source fails.
  let existing: ContentCache | undefined;
  try {
@@ -56,17 +63,29 @@ async function main() {
    log("YouTube: skipped (missing YOUTUBE_CHANNEL_ID)");
  } else if (cfg.youtubeApiKey) {
    try {
-      const items = await fetchYoutubeViaApi(cfg.youtubeChannelId, cfg.youtubeApiKey, 25);
+      const cacheKey = `youtube:api:${cfg.youtubeChannelId}:25`;
+      const { value: items, cached } = await cachedCompute(kv, cacheKey, () =>
+        fetchYoutubeViaApi(cfg.youtubeChannelId!, cfg.youtubeApiKey!, 25),
+      );
+      log(`YouTube: API ${cached ? "cache" : "live"} (${items.length} items)`);
      log(`YouTube: API ok (${items.length} items)`);
      all.push(...items);
    } catch (e) {
      log(`YouTube: API failed (${String(e)}), falling back to RSS`);
-      const items = await fetchYoutubeViaRss(cfg.youtubeChannelId, 25);
+      const cacheKey = `youtube:rss:${cfg.youtubeChannelId}:25`;
+      const { value: items, cached } = await cachedCompute(kv, cacheKey, () =>
+        fetchYoutubeViaRss(cfg.youtubeChannelId!, 25),
+      );
+      log(`YouTube: RSS ${cached ? "cache" : "live"} (${items.length} items)`);
      log(`YouTube: RSS ok (${items.length} items)`);
      all.push(...items);
    }
  } else {
-    const items = await fetchYoutubeViaRss(cfg.youtubeChannelId, 25);
+    const cacheKey = `youtube:rss:${cfg.youtubeChannelId}:25`;
+    const { value: items, cached } = await cachedCompute(kv, cacheKey, () =>
+      fetchYoutubeViaRss(cfg.youtubeChannelId!, 25),
+    );
+    log(`YouTube: RSS ${cached ? "cache" : "live"} (${items.length} items)`);
    log(`YouTube: RSS ok (${items.length} items)`);
    all.push(...items);
  }
@@ -76,7 +95,11 @@ async function main() {
    log("Podcast: skipped (missing PODCAST_RSS_URL)");
  } else {
    try {
-      const items = await fetchPodcastRss(cfg.podcastRssUrl, 50);
+      const cacheKey = `podcast:rss:${cfg.podcastRssUrl}:50`;
+      const { value: items, cached } = await cachedCompute(kv, cacheKey, () =>
+        fetchPodcastRss(cfg.podcastRssUrl!, 50),
+      );
+      log(`Podcast: RSS ${cached ? "cache" : "live"} (${items.length} items)`);
      log(`Podcast: RSS ok (${items.length} items)`);
      all.push(...items);
    } catch (e) {
@@ -103,11 +126,17 @@ async function main() {
    wordpress = existing?.wordpress || wordpress;
  } else {
    try {
-      const wp = await fetchWordpressContent({
-        baseUrl: cfg.wordpressBaseUrl,
-        username: cfg.wordpressUsername,
-        appPassword: cfg.wordpressAppPassword,
-      });
+      const cacheKey = `wp:content:${cfg.wordpressBaseUrl}`;
+      const { value: wp, cached } = await cachedCompute(kv, cacheKey, () =>
+        fetchWordpressContent({
+          baseUrl: cfg.wordpressBaseUrl!,
+          username: cfg.wordpressUsername,
+          appPassword: cfg.wordpressAppPassword,
+        }),
+      );
+      log(
+        `WordPress: wp-json ${cached ? "cache" : "live"} (${wp.posts.length} posts, ${wp.pages.length} pages, ${wp.categories.length} categories)`,
+      );
      wordpress = wp;
      log(
        `WordPress: wp-json ok (${wp.posts.length} posts, ${wp.pages.length} pages, ${wp.categories.length} categories)`,
@@ -119,14 +148,16 @@ async function main() {
    }
  }

-  const cache: ContentCache = {
+  const contentCache: ContentCache = {
    generatedAt,
    items: dedupe(all),
    wordpress,
  };

-  await writeAtomic(outPath, JSON.stringify(cache, null, 2));
-  log(`Wrote cache: ${outPath} (${cache.items.length} total items)`);
+  await writeAtomic(outPath, JSON.stringify(contentCache, null, 2));
+  log(`Wrote cache: ${outPath} (${contentCache.items.length} total items)`);
+
+  await kv.close();
 }

 main().catch((e) => {
--- a/site/src/lib/cache/index.ts
+++ b/site/src/lib/cache/index.ts
@@ -0,0 +1,28 @@
+import type { CacheLogFn, CacheStore } from "./redis-cache";
+import {
+  createRedisCache,
+  resolveDefaultTtlSecondsFromEnv,
+  resolveRedisUrlFromEnv,
+} from "./redis-cache";
+import { createNoopCache } from "./noop-cache";
+
+export async function createCacheFromEnv(
+  env: NodeJS.ProcessEnv,
+  opts?: { namespace?: string; log?: CacheLogFn },
+): Promise<CacheStore> {
+  const url = resolveRedisUrlFromEnv(env);
+  if (!url) return createNoopCache(opts?.log);
+
+  try {
+    return await createRedisCache({
+      url,
+      defaultTtlSeconds: resolveDefaultTtlSecondsFromEnv(env),
+      namespace: opts?.namespace,
+      log: opts?.log,
+    });
+  } catch (e) {
+    opts?.log?.(`cache: disabled (redis connect failed: ${String(e)})`);
+    return createNoopCache(opts?.log);
+  }
+}
+
--- a/site/src/lib/cache/memoize.ts
+++ b/site/src/lib/cache/memoize.ts
@@ -0,0 +1,16 @@
+import type { CacheStore } from "./redis-cache";
+
+export async function cachedCompute<T>(
+  cache: CacheStore,
+  key: string,
+  compute: () => Promise<T>,
+  ttlSeconds?: number,
+): Promise<{ value: T; cached: boolean }> {
+  const hit = await cache.getJson<T>(key);
+  if (hit !== undefined) return { value: hit, cached: true };
+
+  const value = await compute();
+  await cache.setJson(key, value, ttlSeconds);
+  return { value, cached: false };
+}
+
--- a/site/src/lib/cache/memory-cache.ts
+++ b/site/src/lib/cache/memory-cache.ts
@@ -0,0 +1,49 @@
+import type { CacheStore } from "./redis-cache";
+
+type Entry = { value: string; expiresAt: number };
+
+export function createMemoryCache(defaultTtlSeconds: number): CacheStore {
+  const store = new Map<string, Entry>();
+
+  function nowMs() {
+    return Date.now();
+  }
+
+  function isExpired(e: Entry) {
+    return e.expiresAt !== 0 && nowMs() > e.expiresAt;
+  }
+
+  return {
+    async getJson<T>(key: string) {
+      const e = store.get(key);
+      if (!e) return undefined;
+      if (isExpired(e)) {
+        store.delete(key);
+        return undefined;
+      }
+      try {
+        return JSON.parse(e.value) as T;
+      } catch {
+        store.delete(key);
+        return undefined;
+      }
+    },
+
+    async setJson(key: string, value: unknown, ttlSeconds?: number) {
+      const ttl = Math.max(1, Math.floor(ttlSeconds ?? defaultTtlSeconds));
+      store.set(key, {
+        value: JSON.stringify(value),
+        expiresAt: nowMs() + ttl * 1000,
+      });
+    },
+
+    async flush() {
+      store.clear();
+    },
+
+    async close() {
+      // no-op
+    },
+  };
+}
+
--- a/site/src/lib/cache/noop-cache.ts
+++ b/site/src/lib/cache/noop-cache.ts
@@ -0,0 +1,19 @@
+import type { CacheLogFn, CacheStore } from "./redis-cache";
+
+export function createNoopCache(log?: CacheLogFn): CacheStore {
+  return {
+    async getJson() {
+      return undefined;
+    },
+    async setJson() {
+      // no-op
+    },
+    async flush() {
+      log?.("cache: noop flush");
+    },
+    async close() {
+      // no-op
+    },
+  };
+}
+
--- a/site/src/lib/cache/redis-cache.ts
+++ b/site/src/lib/cache/redis-cache.ts
@@ -0,0 +1,92 @@
+import { createClient } from "redis";
+
+export type CacheLogFn = (msg: string) => void;
+
+export type CacheStore = {
+  getJson<T>(key: string): Promise<T | undefined>;
+  setJson(key: string, value: unknown, ttlSeconds?: number): Promise<void>;
+  flush(): Promise<void>;
+  close(): Promise<void>;
+};
+
+type RedisCacheOptions = {
+  url: string;
+  defaultTtlSeconds: number;
+  namespace?: string;
+  log?: CacheLogFn;
+};
+
+function nsKey(namespace: string | undefined, key: string) {
+  return namespace ? `${namespace}:${key}` : key;
+}
+
+export async function createRedisCache(opts: RedisCacheOptions): Promise<CacheStore> {
+  const log = opts.log;
+  const client = createClient({ url: opts.url });
+
+  client.on("error", (err) => {
+    log?.(`cache: redis error (${String(err)})`);
+  });
+
+  await client.connect();
+
+  return {
+    async getJson<T>(key: string) {
+      const k = nsKey(opts.namespace, key);
+      const raw = await client.get(k);
+      if (raw == null) {
+        log?.(`cache: miss ${k}`);
+        return undefined;
+      }
+      log?.(`cache: hit ${k}`);
+      try {
+        return JSON.parse(raw) as T;
+      } catch {
+        // Bad cache entry: treat as miss.
+        return undefined;
+      }
+    },
+
+    async setJson(key: string, value: unknown, ttlSeconds?: number) {
+      const k = nsKey(opts.namespace, key);
+      const ttl = Math.max(1, Math.floor(ttlSeconds ?? opts.defaultTtlSeconds));
+      const raw = JSON.stringify(value);
+      await client.set(k, raw, { EX: ttl });
+    },
+
+    async flush() {
+      await client.flushDb();
+    },
+
+    async close() {
+      try {
+        await client.quit();
+      } catch {
+        // ignore
+      }
+    },
+  };
+}
+
+export function resolveRedisUrlFromEnv(env: NodeJS.ProcessEnv): string | undefined {
+  const url = env.CACHE_REDIS_URL;
+  if (url) return url;
+
+  const host = env.CACHE_REDIS_HOST;
+  const port = env.CACHE_REDIS_PORT;
+  const db = env.CACHE_REDIS_DB;
+
+  if (!host) return undefined;
+  const p = port ? Number(port) : 6379;
+  const d = db ? Number(db) : 0;
+  if (!Number.isFinite(p) || !Number.isFinite(d)) return undefined;
+  return `redis://${host}:${p}/${d}`;
+}
+
+export function resolveDefaultTtlSecondsFromEnv(env: NodeJS.ProcessEnv): number {
+  const raw = env.CACHE_DEFAULT_TTL_SECONDS;
+  const n = raw ? Number(raw) : NaN;
+  if (Number.isFinite(n) && n > 0) return Math.floor(n);
+  return 3600;
+}
+
--- a/site/src/lib/config.ts
+++ b/site/src/lib/config.ts
@@ -14,6 +14,11 @@ type IngestConfig = {
  wordpressBaseUrl?: string;
  wordpressUsername?: string;
  wordpressAppPassword?: string;
+  cacheRedisUrl?: string;
+  cacheRedisHost?: string;
+  cacheRedisPort?: number;
+  cacheRedisDb?: number;
+  cacheDefaultTtlSeconds?: number;
 };

 export function getPublicConfig(): PublicConfig {
@@ -37,5 +42,12 @@ export function getIngestConfigFromEnv(env: NodeJS.ProcessEnv): IngestConfig {
    wordpressBaseUrl: env.WORDPRESS_BASE_URL,
    wordpressUsername: env.WORDPRESS_USERNAME,
    wordpressAppPassword: env.WORDPRESS_APP_PASSWORD,
+    cacheRedisUrl: env.CACHE_REDIS_URL,
+    cacheRedisHost: env.CACHE_REDIS_HOST,
+    cacheRedisPort: env.CACHE_REDIS_PORT ? Number(env.CACHE_REDIS_PORT) : undefined,
+    cacheRedisDb: env.CACHE_REDIS_DB ? Number(env.CACHE_REDIS_DB) : undefined,
+    cacheDefaultTtlSeconds: env.CACHE_DEFAULT_TTL_SECONDS
+      ? Number(env.CACHE_DEFAULT_TTL_SECONDS)
+      : undefined,
  };
 }
--- a/site/tests/cache-wrapper.test.ts
+++ b/site/tests/cache-wrapper.test.ts
@@ -0,0 +1,40 @@
+import { describe, expect, it } from "vitest";
+
+import { createMemoryCache } from "../src/lib/cache/memory-cache";
+import { cachedCompute } from "../src/lib/cache/memoize";
+
+function sleep(ms: number) {
+  return new Promise((r) => setTimeout(r, ms));
+}
+
+describe("cache wrapper", () => {
+  it("set/get JSON and expires by TTL", async () => {
+    const cache = createMemoryCache(1);
+    await cache.setJson("k", { a: 1 }, 1);
+
+    const v1 = await cache.getJson<{ a: number }>("k");
+    expect(v1).toEqual({ a: 1 });
+
+    await sleep(1100);
+    const v2 = await cache.getJson("k");
+    expect(v2).toBeUndefined();
+  });
+
+  it("cachedCompute hits on second call within TTL", async () => {
+    const cache = createMemoryCache(60);
+    let calls = 0;
+    const compute = async () => {
+      calls++;
+      return { ok: true, n: calls };
+    };
+
+    const r1 = await cachedCompute(cache, "x", compute, 60);
+    const r2 = await cachedCompute(cache, "x", compute, 60);
+
+    expect(r1.cached).toBe(false);
+    expect(r2.cached).toBe(true);
+    expect(calls).toBe(1);
+    expect(r2.value).toEqual(r1.value);
+  });
+});
+