feat(ratelimit): Cloudflare Worker Ratelimit Adapter (#1212)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added Cloudflare as a new ratelimit adapter option with example usage.

* **Documentation**
* Updated adapter docs to include the Cloudflare ratelimit adapter
alongside existing adapters.

* **Tests**
* Added unit tests covering the Cloudflare ratelimit adapter's behavior
and delegation.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: unnoq

apps/content/docs/helpers/ratelimit.md

@@ -72,7 +72,7 @@ const limiter = new RedisRatelimiter({
 You can use any Redis client that supports Lua script evaluation by providing an `eval` function.
 :::
 
-### Upstash Adapter
+### Upstash Ratelimit Adapter
 
 Adapter for [@upstash/ratelimit](https://www.npmjs.com/package/@upstash/ratelimit), optimized for serverless environments like Vercel Edge and Cloudflare Workers.
 
@@ -103,6 +103,22 @@ const limiter = new UpstashRatelimiter(ratelimit, {
 
 :::
 
+### Cloudflare Ratelimit Adapter
+
+Adapter for [Cloudflare Workers Ratelimit](https://developers.cloudflare.com/workers/runtime-apis/bindings/rate-limit/).
+
+```ts
+import { CloudflareRatelimiter } from '@orpc/experimental-ratelimit/cloudflare-ratelimit'
+
+export default {
+  async fetch(request, env) {
+    const limiter = new CloudflareRatelimiter(env.MY_RATE_LIMITER)
+
+    return new Response(`Hello World!`)
+  }
+}
+```
+
 ## Blocking Mode
 
 Some adapters support blocking mode, which waits for the rate limit to reset instead of immediately rejecting requests.

packages/ratelimit/package.json

@@ -34,14 +34,20 @@
         "types": "./dist/adapters/upstash-ratelimit.d.mts",
         "import": "./dist/adapters/upstash-ratelimit.mjs",
         "default": "./dist/adapters/upstash-ratelimit.mjs"
+      },
+      "./cloudflare-ratelimit": {
+        "types": "./dist/adapters/cloudflare-ratelimit.d.mts",
+        "import": "./dist/adapters/cloudflare-ratelimit.mjs",
+        "default": "./dist/adapters/cloudflare-ratelimit.mjs"
       }
     }
   },
   "exports": {
     ".": "./src/index.ts",
     "./memory": "./src/adapters/memory.ts",
     "./redis": "./src/adapters/redis.ts",
-    "./upstash-ratelimit": "./src/adapters/upstash-ratelimit.ts"
+    "./upstash-ratelimit": "./src/adapters/upstash-ratelimit.ts",
+    "./cloudflare-ratelimit": "./src/adapters/cloudflare-ratelimit.ts"
   },
   "files": [
     "dist"

packages/ratelimit/src/adapters/cloudflare-ratelimit.test.ts

@@ -0,0 +1,17 @@
+import { CloudflareRatelimiter } from './cloudflare-ratelimit'
+
+it('cloudflareRatelimiter', async () => {
+  const ratelimit = {
+    limit: vi.fn(() => Promise.resolve({ success: true })),
+  }
+
+  const ratelimiter = new CloudflareRatelimiter(ratelimit)
+
+  const result = ratelimiter.limit('test-key')
+
+  expect(ratelimit.limit).toHaveBeenCalledTimes(1)
+  expect(ratelimit.limit).toHaveBeenCalledWith({ key: 'test-key' })
+  expect(result).toBe(ratelimit.limit.mock.results[0]!.value)
+
+  expect(await result).toEqual({ success: true })
+})

packages/ratelimit/src/adapters/cloudflare-ratelimit.ts

@@ -0,0 +1,13 @@
+import type { Ratelimiter, RatelimiterLimitResult } from '../types'
+
+export class CloudflareRatelimiter implements Ratelimiter {
+  constructor(
+    private readonly ratelimit: {
+      limit: (options: { key: string }) => Promise<RatelimiterLimitResult>
+    },
+  ) {}
+
+  limit(key: string): Promise<RatelimiterLimitResult> {
+    return this.ratelimit.limit({ key })
+  }
+}