[fix] handle incoming requests from HTTP/2 (#3572)

* strip out HTTP/2 headers in getRequest

* remove workaround forcing Vite to use HTTP/1 for dev mode

* add changeset

Author: Conduitry

.changeset/eight-readers-thank.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix handling an incoming request from HTTP/2

packages/kit/src/core/dev/index.js

@@ -85,14 +85,6 @@ export async function dev({ cwd, port, host, https, config }) {
 		merged_config.server.https = https;
 	}
 
-	// by default, when enabling HTTPS in Vite, it also enables HTTP/2
-	// however, node-fetch's Request implementation does not like the HTTP/2 headers
-	// we set a no-op proxy config to force Vite to downgrade to TLS-only
-	// see https://vitejs.dev/config/#server-https
-	if (merged_config.server.https && !merged_config.server.proxy) {
-		merged_config.server.proxy = {};
-	}
-
 	if (port) {
 		merged_config.server.port = port;
 	}

packages/kit/src/node.js

@@ -52,9 +52,19 @@ function get_raw_body(req) {
 
 /** @type {import('@sveltejs/kit/node').GetRequest} */
 export async function getRequest(base, req) {
+	let headers = /** @type {Record<string, string>} */ (req.headers);
+	if (req.httpVersionMajor === 2) {
+		// we need to strip out the HTTP/2 pseudo-headers because node-fetch's
+		// Request implementation doesn't like them
+		headers = Object.assign({}, headers);
+		delete headers[':method'];
+		delete headers[':path'];
+		delete headers[':authority'];
+		delete headers[':scheme'];
+	}
 	return new Request(base + req.url, {
 		method: req.method,
-		headers: /** @type {Record<string, string>} */ (req.headers),
+		headers,
 		body: await get_raw_body(req) // TODO stream rather than buffer
 	});
 }