✨ Cache

• Cache ReferenceOpen external link
• How the Cache worksOpen external link (note that cache using fetch is unsupported)

​Default Cache

Access to the default cache is enabled by default:

addEventListener("fetch", (e) => {
  e.respondWith(caches.default.match("http://miniflare.dev"));
});

​Named Caches

You can access a namespaced cache using open. Note that you cannot name your cache default, trying to do so will throw an error:

await caches.open("cache_name");

​Persistence

By default, cached data is stored in memory. It will persist between reloads, but not different Miniflare instances. To enable persistence to the file system or Redis, specify the cache persistence option:

const mf = new Miniflare({
  cachePersist: true, // Defaults to ./.mf/cache
  cachePersist: "./data", // Custom path
  cachePersist: "redis://localhost:6379", // Redis server
});

When using the file system, each namespace will get its own directory within the cache persistence directory.

​Manipulating Outside Workers

For testing, it can be useful to put/match data from cache outside a worker. You can do this with the getCaches method:

import { Miniflare, Response } from "miniflare";

const mf = new Miniflare({
  modules: true,
  script: `
  export default {
    async fetch(request) {
      const url = new URL(request.url);
      const cache = caches.default;
      if(url.pathname === "/put") {
        await cache.put("https://miniflare.dev/", new Response("1", {
          headers: { "Cache-Control": "max-age=3600" },
        }));
      }
      return cache.match("https://miniflare.dev/");
    }
  }
  `,
});
let res = await mf.dispatchFetch("http://localhost:8787/put");
console.log(await res.text()); // 1

const caches = await mf.getCaches(); // Gets the global caches object
const cachedRes = await caches.default.match("https://miniflare.dev/");
console.log(await cachedRes.text()); // 1

await caches.default.put(
  "https://miniflare.dev",
  new Response("2", {
    headers: { "Cache-Control": "max-age=3600" },
  })
);
res = await mf.dispatchFetch("http://localhost:8787");
console.log(await res.text()); // 2

​Disabling

Both default and named caches can be disabled with the disableCache option. When disabled, the caches will still be available in the sandbox, they just won't cache anything. This may be useful during development:

const mf = new Miniflare({
  cache: false,
});

​Subrequests

Like the real workers runtime, Miniflare limits you to 50 subrequests per requestOpen external link. Each call to fetch(), each URL in a redirect chain, and each call to a Cache API method (put()/match()/delete()) counts as a subrequest.