Iterate manually over response.body

I'm honestly not sure if there is a problem in Node itself or in undici, but I'm seeing issues with the stream reader not releasing its lock properly when using `for await...of` to iterate over `response.body` in `sendResponse`. In any case, there may be a variety of `Response` implementations that people eventually want to use with this, and async iterators are hard to get right, so dropping down to the lower-level `getReader()` API for stream iteration seems like a prudent move.

packages/node-fetch-server/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 This is the changelog for [`node-fetch-server`](https://github.com/mjackson/remix-the-web/tree/main/packages/node-fetch-server). It follows [semantic versioning](https://semver.org/).
 
+## HEAD
+
+- Iterate manually over response bodies in `sendResponse` instead of using `for await...of`. This seems to avoid an issue where the iterator tries to read from a stream after the lock has been released.
+
 ## v0.5.0 (2024-12-09)
 
 - Expose `createHeaders(req: http.IncomingMessage): Headers` API for creating headers from the headers of incoming request objects.

packages/node-fetch-server/src/lib/read-stream.ts

@@ -0,0 +1,9 @@
+export async function* readStream(stream: ReadableStream<Uint8Array>): AsyncIterable<Uint8Array> {
+  let reader = stream.getReader();
+
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    yield value;
+  }
+}

packages/node-fetch-server/src/lib/request-listener.ts

@@ -1,6 +1,7 @@
 import type * as http from 'node:http';
 
 import { type ClientAddress, type ErrorHandler, type FetchHandler } from './fetch-handler.ts';
+import { readStream } from './read-stream.ts';
 
 export interface RequestListenerOptions {
   /**
@@ -204,7 +205,7 @@ export async function sendResponse(res: http.ServerResponse, response: Response)
   res.writeHead(response.status, headers);
 
   if (response.body != null && res.req.method !== 'HEAD') {
-    for await (let chunk of response.body) {
+    for await (let chunk of readStream(response.body)) {
       res.write(chunk);
     }
   }