Fix fatal error when parsing URLs in Node adapter (#802)

* fix parsing url in node adapter

* add changeset

* simplify vercel url parsing

* add changelog

.changeset/silver-elephants-tap.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-node': patch
+---
+
+Fix fatal error when trying to parse URLs of incoming requests

.changeset/witty-eyes-relax.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-vercel': patch
+---
+
+Simplify parsing of URLS of incoming requests

packages/adapter-node/src/server.js

@@ -31,7 +31,7 @@ const assets_handler = sirv(join(__dirname, '/assets'), {
 
 polka()
 	.use(compression({ threshold: 0 }), assets_handler, prerendered_handler, async (req, res) => {
-		const parsed = new URL(req.url || '');
+		const parsed = new URL(req.url || '', 'http://localhost');
 		const rendered = await app.render({
 			method: req.method,
 			headers: req.headers, // TODO: what about repeated headers, i.e. string[]

packages/adapter-vercel/src/entry.js

@@ -3,8 +3,7 @@ import { URL } from 'url';
 import { get_body } from '@sveltejs/kit/http';
 
 export default async (req, res) => {
-	const host = `${req.headers['x-forwarded-proto']}://${req.headers.host}`;
-	const { pathname, searchParams } = new URL(req.url || '', host);
+	const { pathname, searchParams } = new URL(req.url || '', 'http://localhost');
 
 	const { render } = await import('./server/app.mjs');