Using miniflare for Cloudflare Worker KV in Astro

get_kv.ts

import { getRuntime } from "@astrojs/cloudflare/runtime";
import type { KVNamespace } from "@cloudflare/workers-types";

/** The KV key (eg, env["KV"]) */
const KV_KEY = "KV" as const;

/**
 * Returns a Cloudflare Worker KV store.
 * In dev, it returns a mock one based on Miniflare.
 */

export async function getKV(request: Request): Promise<KVNamespace> {
  if (import.meta.env.DEV) return getMockKV();

  const kv = getRuntimeKV(request);
  if (kv) return kv;

  throw "No KV provider available";
}

type Env = {
  [key in typeof KV_KEY]: KVNamespace;
}

export async function getRuntimeKV(request: Request): Promise<KVNamespace> {
  const runtime = getRuntime<Env>(request);
  // runtime: { env: { KV: KVNamespace {}, ASSETS: Fetcher {} }, name: 'cloudflare' }
  const kv = runtime?.env[KV_KEY];
  return kv;
}

export async function getMockKV(): Promise<KVNamespace> {
  (global as any).miniflare ??= await (async () => {
    const { Miniflare } = await import("miniflare");
    return new Miniflare({
      kvNamespaces: [KV_KEY],
      script: '',
    });
  })();

  return (global as any).miniflare.getKVNamespace(KV_KEY);
}

index.ts

// Example: using miniflare for Cloudflare Worker KV in Astro
//
// Running astro in development mode (`astro dev`) won't allow you to
// use Cloudflare features like KV. To get around this, we can use
// `miniflare`.

import { getKV } from "./get_kv";

// instead of using `getRuntime(request).env.KV` to get the KV instance,
// use this:
const kv = getKV();

kv.put("hello", "world");
kv.delete("hello");