feat: support Cloudflare Workers

README.md

@@ -7,14 +7,51 @@ designed for Deno CLI, Deno Deploy and Bun.
 
 ## Usage
 
-### Under Deno CLI or Deploy
+### Under Deno runtime or Deploy
 
-You need to import the package into your code:
+Add the package to your project:
+
+```
+deno add @oak/acorn
+```
+
+### Under Node.js and Cloudflare Workers
+
+Install the package using your chosen package manager:
+
+#### npm
+
+```
+npx jsr add @oak/acorn
+```
+
+#### Yarn
+
+```
+yarn dlx jsr add @oak/acorn
+```
+
+#### pnpm
+
+```
+pnpm dlx jsr add @oak/acorn
+```
+
+### Under Bun
+
+```
+bunx jsr add @oak/acorn
+```
+
+### Listening
+
+For Deno, Node.js, and Bun the router needs to be configured and then start
+listening for requests:
 
 ```ts
-import { Router } from "jsr:@oak/acorn/router";
+import { Router } from "@oak/acorn";
 
-const BOOKS: Record<string, { id: number; title: string }> = {
+const BOOKS = {
   "1": { id: 1, title: "The Hound of the Baskervilles" },
   "2": { id: 2, title: "It" },
 };
@@ -27,20 +64,15 @@ router.get("/books/:id", (ctx) => BOOKS[ctx.params.id]);
 router.listen({ port: 5000 });
 ```
 
-### Under Bun
-
-You need to add the package to your project:
-
-```
-bunx jsr add @oak/acorn
-```
+### Fetch handlers
 
-Then you need to import the package into your code:
+For Cloudflare Workers the router needs to be configured and the router's fetch
+handler needs to be exported:
 
 ```ts
-import { Router } from "@oak/acorn/router";
+import { Router } from "@oak/acorn";
 
-const BOOKS: Record<string, { id: number; title: string }> = {
+const BOOKS = {
   "1": { id: 1, title: "The Hound of the Baskervilles" },
   "2": { id: 2, title: "It" },
 };
@@ -51,6 +83,8 @@ router.get("/", () => ({ hello: "world" }));
 router.get("/books/:id", (ctx) => BOOKS[ctx.params.id]);
 
 router.listen({ port: 5000 });
+
+export default { fetch: router.fetch };
 ```
 
 ## Philosophy

deno.json

@@ -1,6 +1,6 @@
 {
   "name": "@oak/acorn",
-  "version": "0.6.0",
+  "version": "0.7.0-alpha.1",
   "exports": {
     ".": "./mod.ts",
     "./context": "./context.ts",

request_event_cloudflare.ts

@@ -0,0 +1,62 @@
+// Copyright 2022-2024 the oak authors. All rights reserved.
+
+import type {
+  Addr,
+  CloudflareExecutionContext,
+  RequestEvent as _RequestEvent,
+} from "./types_internal.ts";
+import { createPromiseWithResolvers } from "./util.ts";
+
+export class RequestEvent<
+  Env extends Record<string, string> = Record<string, string>,
+> implements _RequestEvent {
+  #addr?: Addr;
+  //deno-lint-ignore no-explicit-any
+  #reject: (reason?: any) => void;
+  #request: Request;
+  #resolve: (value: Response | PromiseLike<Response>) => void;
+  #resolved = false;
+  #response: Promise<Response>;
+
+  get addr(): Addr {
+    if (!this.#addr) {
+      const hostname = this.#request.headers.get("CF-Connecting-IP") ??
+        "localhost";
+      this.#addr = { hostname, port: 80, transport: "tcp" };
+    }
+    return this.#addr;
+  }
+
+  get request(): Request {
+    return this.#request;
+  }
+
+  get response(): Promise<Response> {
+    return this.#response;
+  }
+
+  constructor(request: Request, _env: Env, _ctx: CloudflareExecutionContext) {
+    this.#request = request;
+    const { resolve, reject, promise } = createPromiseWithResolvers<Response>();
+    this.#resolve = resolve;
+    this.#reject = reject;
+    this.#response = promise;
+  }
+
+  //deno-lint-ignore no-explicit-any
+  error(reason?: any): void {
+    if (this.#resolved) {
+      throw new Error("Request already responded to.");
+    }
+    this.#resolved = true;
+    this.#reject(reason);
+  }
+
+  respond(response: Response | PromiseLike<Response>): void {
+    if (this.#resolved) {
+      throw new Error("Request already responded to.");
+    }
+    this.#resolved = true;
+    this.#resolve(response);
+  }
+}

router.ts

@@ -38,9 +38,12 @@ import {
   SecureCookieMap,
   Status,
 } from "./deps.ts";
+import type { RequestEvent as CloudFlareRequestEvent } from "./request_event_cloudflare.ts";
 import type { Deserializer, KeyRing, Serializer } from "./types.ts";
 import type {
   Addr,
+  CloudflareExecutionContext,
+  CloudflareFetchHandler,
   Destroyable,
   Listener,
   RequestEvent,
@@ -184,6 +187,8 @@ const HTTP_VERBS = [
 
 const HANDLE_START = "handle start";
 
+let RequestEventCtor: typeof CloudFlareRequestEvent | undefined;
+
 type HTTPVerbs = typeof HTTP_VERBS[number];
 
 /** A string that represents a range of HTTP response {@linkcode Status} codes:
@@ -1461,6 +1466,40 @@ export class Router extends EventTarget {
     return promise;
   }
 
+  /**
+   * A method that is compatible with the Cloudflare Worker
+   * [Fetch Handler](https://developers.cloudflare.com/workers/runtime-apis/handlers/fetch/)
+   * and can be exported to handle Cloudflare Worker fetch requests.
+   *
+   * @example
+   *
+   * ```ts
+   * import { Router } from "@oak/acorn";
+   *
+   * const router = new Router();
+   * router.get("/", (ctx) => {
+   *   ctx.response.body = "hello world!";
+   * });
+   *
+   * export default { fetch: router.fetch };
+   * ```
+   */
+  fetch: CloudflareFetchHandler = async <
+    Env extends Record<string, string> = Record<string, string>,
+  >(
+    request: Request,
+    env: Env,
+    ctx: CloudflareExecutionContext,
+  ): Promise<Response> => {
+    if (!RequestEventCtor) {
+      RequestEventCtor =
+        (await import("./request_event_cloudflare.ts")).RequestEvent;
+    }
+    const requestEvent = new RequestEventCtor(request, env, ctx);
+    this.#handle(requestEvent);
+    return requestEvent.response;
+  };
+
   /** Open a server to listen for requests and handle them by matching against
    * registered routes.
    *

types_internal.ts

@@ -1,3 +1,37 @@
+// Copyright 2022-2024 the oak authors. All rights reserved.
+
+export interface CloudflareExecutionContext {
+  waitUntil(promise: Promise<unknown>): void;
+  passThroughOnException(): void;
+}
+
+export interface CloudflareFetchHandler<
+  Env extends Record<string, string> = Record<string, string>,
+> {
+  /** A method that is compatible with the Cloudflare Worker
+   * [Fetch Handler](https://developers.cloudflare.com/workers/runtime-apis/handlers/fetch/)
+   * and can be exported to handle Cloudflare Worker fetch requests.
+   *
+   * # Example
+   *
+   * ```ts
+   * import { Application } from "@oak/oak";
+   *
+   * const app = new Application();
+   * app.use((ctx) => {
+   *   ctx.response.body = "hello world!";
+   * });
+   *
+   * export default { fetch: app.fetch };
+   * ```
+   */
+  (
+    request: Request,
+    env: Env,
+    ctx: CloudflareExecutionContext,
+  ): Promise<Response>;
+}
+
 export interface RequestEvent {
   readonly addr: Addr;
   readonly request: Request;