Cache

• Cache Reference
• How the Cache works (note that cache using fetch is unsupported)

Default Cache

Access to the default cache is enabled by default:

JavaScript

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:

JavaScript

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, specify the cache persistence option:

JavaScript

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

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:

JavaScript

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

Explain Code

Purging

You can programmatically purge all entries from a cache using the purgeCache method on the Miniflare instance. This is useful during development when cached assets need to be cleared without restarting the instance:

JavaScript

const mf = new Miniflare({ /* options */ });

// Purge the default cache and get the number of entries purged
const count = await mf.purgeCache();
console.log(`Purged ${count} entries`);

// Purge a specific named cache
await mf.purgeCache("my-named-cache");

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:

JavaScript

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