Revert "Undici (#5117)"

This reverts commit 7ed3c95.

documentation/docs/01-web-standards.md

@@ -45,10 +45,6 @@ export function get(event) {
 }
 ```
 
-### Stream APIs
-
-Most of the time, your endpoints will return complete data, as in the `userAgent` example above. Sometimes, you may need to return a response that's too large to fit in memory in one go, or is delivered in chunks, and for this the platform provides [streams](https://developer.mozilla.org/en-US/docs/Web/API/Streams_API) — [ReadableStream](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream), [WritableStream](https://developer.mozilla.org/en-US/docs/Web/API/WritableStream) and [TransformStream](https://developer.mozilla.org/en-US/docs/Web/API/TransformStream).
-
 ### URL APIs
 
 URLs are represented by the [`URL`](https://developer.mozilla.org/en-US/docs/Web/API/URL) interface, which includes useful properties like `origin` and `pathname` (and, in the browser, `hash`). This interface shows up in various places — `event.url` in [hooks](/docs/hooks) and [endpoints](/docs/routing#endpoints), [`$page.url`](/docs/modules#$app-stores) in [pages](/docs/routing#pages), `from` and `to` in [`beforeNavigate` and `afterNavigate`](/docs/modules#$app-navigation) and so on.

packages/kit/package.json

@@ -33,6 +33,7 @@
 		"locate-character": "^2.0.5",
 		"marked": "^4.0.16",
 		"mime": "^3.0.0",
+		"node-fetch": "^3.2.4",
 		"port-authority": "^1.2.0",
 		"rollup": "^2.75.3",
 		"selfsigned": "^2.0.1",
@@ -44,7 +45,6 @@
 		"svelte2tsx": "~0.5.10",
 		"tiny-glob": "^0.2.9",
 		"typescript": "^4.7.2",
-		"undici": "^5.4.0",
 		"uvu": "^0.5.3"
 	},
 	"peerDependencies": {

packages/kit/src/node/index.js

@@ -1,3 +1,4 @@
+import { Readable } from 'stream';
 import * as set_cookie_parser from 'set-cookie-parser';
 
 /** @param {import('http').IncomingMessage} req */
@@ -63,7 +64,6 @@ export async function getRequest(base, req) {
 		delete headers[':authority'];
 		delete headers[':scheme'];
 	}
-
 	return new Request(base + req.url, {
 		method: req.method,
 		headers,
@@ -85,38 +85,13 @@ export async function setResponse(res, response) {
 
 	res.writeHead(response.status, headers);
 
-	if (response.body) {
-		let cancelled = false;
-
-		const reader = response.body.getReader();
-
-		res.on('close', () => {
-			reader.cancel();
-			cancelled = true;
-		});
-
-		const next = async () => {
-			const { done, value } = await reader.read();
-
-			if (cancelled) return;
-
-			if (done) {
-				res.end();
-				return;
-			}
-
-			res.write(Buffer.from(value), (error) => {
-				if (error) {
-					console.error('Error writing stream', error);
-					res.end();
-				} else {
-					next();
-				}
-			});
-		};
-
-		next();
+	if (response.body instanceof Readable) {
+		response.body.pipe(res);
 	} else {
+		if (response.body) {
+			res.write(new Uint8Array(await response.arrayBuffer()));
+		}
+
 		res.end();
 	}
 }

packages/kit/src/node/polyfills.js

@@ -1,5 +1,4 @@
-import { fetch, Response, Request, Headers } from 'undici';
-import { ReadableStream, TransformStream, WritableStream } from 'stream/web';
+import fetch, { Response, Request, Headers } from 'node-fetch';
 import { webcrypto as crypto } from 'crypto';
 
 /** @type {Record<string, any>} */
@@ -8,17 +7,13 @@ const globals = {
 	fetch,
 	Response,
 	Request,
-	Headers,
-	ReadableStream,
-	TransformStream,
-	WritableStream
+	Headers
 };
 
 // exported for dev/preview and node environments
 export function installPolyfills() {
 	for (const name in globals) {
-		if (name in globalThis) continue;
-
+		// TODO use built-in fetch once https://github.com/nodejs/undici/issues/1262 is resolved
 		Object.defineProperty(globalThis, name, {
 			enumerable: true,
 			configurable: true,

packages/kit/src/runtime/server/endpoint.js

@@ -21,8 +21,6 @@ const text_types = new Set([
 	'multipart/form-data'
 ]);
 
-const bodyless_status_codes = new Set([101, 204, 205, 304]);
-
 /**
  * Decides how the body should be parsed based on its mime type
  *
@@ -126,11 +124,8 @@ export async function render_endpoint(event, mod) {
 		}
 	}
 
-	return new Response(
-		method !== 'head' && !bodyless_status_codes.has(status) ? normalized_body : undefined,
-		{
-			status,
-			headers
-		}
-	);
+	return new Response(method !== 'head' ? normalized_body : undefined, {
+		status,
+		headers
+	});
 }

packages/kit/src/runtime/server/page/load_node.js

@@ -250,11 +250,6 @@ export async function load_node({
 						if (cookie) opts.headers.set('cookie', cookie);
 					}
 
-					// we need to delete the connection header, as explained here:
-					// https://github.com/nodejs/undici/issues/1470#issuecomment-1140798467
-					// TODO this may be a case for being selective about which headers we let through
-					opts.headers.delete('connection');
-
 					const external_request = new Request(requested, /** @type {RequestInit} */ (opts));
 					response = await options.hooks.externalFetch.call(null, external_request);
 				}

packages/kit/src/runtime/server/utils.js

@@ -39,13 +39,9 @@ export function is_pojo(body) {
 	if (body) {
 		if (body instanceof Uint8Array) return false;
 
-		// if body is a node Readable, throw an error
-		// TODO remove this for 1.0
-		if (body._readableState && typeof body.pipe === 'function') {
-			throw new Error('Node streams are no longer supported — use a ReadableStream instead');
-		}
-
-		if (body instanceof ReadableStream) return false;
+		// body could be a node Readable, but we don't want to import
+		// node built-ins, so we use duck typing
+		if (body._readableState && typeof body.pipe === 'function') return false;
 
 		// similarly, it could be a web ReadableStream
 		if (typeof ReadableStream !== 'undefined' && body instanceof ReadableStream) return false;

packages/kit/src/utils/http.spec.js

@@ -1,9 +1,7 @@
 import { test } from 'uvu';
 import * as assert from 'uvu/assert';
 import { to_headers } from './http.js';
-import { Headers } from 'undici';
-
-// @ts-ignore
+import { Headers } from 'node-fetch';
 globalThis.Headers = Headers;
 
 test('handle header string value', () => {

packages/kit/test/apps/basics/src/routes/load/large-response/index.svelte → packages/kit/test/apps/basics/src/routes/load/large-response.svelte

@@ -1,7 +1,7 @@
 <script context="module">
 	/** @type {import('@sveltejs/kit').Load} */
-	export async function load({ fetch }) {
-		const res = await fetch('/load/large-response/text.txt');
+	export async function load({ url, fetch }) {
+		const res = await fetch(`http://localhost:${url.searchParams.get('port')}/large-response.json`);
 		const text = await res.text();
 
 		return {

packages/kit/test/apps/basics/test/test.js

@@ -1360,8 +1360,45 @@ test.describe.parallel('Load', () => {
 	test('handles large responses', async ({ page }) => {
 		await page.goto('/load');
 
-		await page.goto('/load/large-response');
-		expect(await page.textContent('h1')).toBe('text.length is 5000000');
+		const chunk_size = 50000;
+		const chunk_count = 100;
+		const total_size = chunk_size * chunk_count;
+
+		let chunk = '';
+		for (let i = 0; i < chunk_size; i += 1) {
+			chunk += String(i % 10);
+		}
+
+		let times_responded = 0;
+
+		const { port, server } = await start_server(async (req, res) => {
+			if (req.url === '/large-response.json') {
+				times_responded += 1;
+
+				res.writeHead(200, {
+					'Access-Control-Allow-Origin': '*'
+				});
+
+				for (let i = 0; i < chunk_count; i += 1) {
+					if (!res.write(chunk)) {
+						await new Promise((fulfil) => {
+							res.once('drain', () => {
+								fulfil(undefined);
+							});
+						});
+					}
+				}
+
+				res.end();
+			}
+		});
+
+		await page.goto(`/load/large-response?port=${port}`);
+		expect(await page.textContent('h1')).toBe(`text.length is ${total_size}`);
+
+		expect(times_responded).toBe(1);
+
+		server.close();
 	});
 
 	test('handles external api', async ({ page }) => {

packages/kit/test/typings/endpoint.test.ts

@@ -51,6 +51,14 @@ export const readable_stream_body: RequestHandler = () => {
 	};
 };
 
+// valid - body instance of stream.Readable should be allowed
+export const stream_readable_body: RequestHandler = async () => {
+	const { Readable } = await import('stream');
+	return {
+		body: new Readable()
+	};
+};
+
 // valid - different header pairs should be allowed
 export const differential_headers_assignment: RequestHandler = () => {
 	if (Math.random() < 0.5) {
@@ -185,11 +193,3 @@ export const error_nested_instances: RequestHandler = () => {
 		body: { typed: new Uint8Array() }
 	};
 };
-
-// @ts-expect-error - instances cannot be nested
-export const stream_readable_body: RequestHandler = async () => {
-	const { Readable } = await import('stream');
-	return {
-		body: new Readable()
-	};
-};

packages/kit/types/index.d.ts

@@ -268,7 +268,7 @@ export interface ResolveOptions {
 	transformPage?: ({ html }: { html: string }) => MaybePromise<string>;
 }
 
-export type ResponseBody = JSONValue | Uint8Array | ReadableStream;
+export type ResponseBody = JSONValue | Uint8Array | ReadableStream | import('stream').Readable;
 
 export class Server {
 	constructor(manifest: SSRManifest);