fix: don't send "Vary: Accept-Encoding" header when precompress=false (sveltejs#15182)

* Disable sirv compression checks when precompress=false

* Add changeset

* Update .changeset/sweet-spoons-study.md

---------

Co-authored-by: Elliott Johnson <hello@ell.iott.dev>

Author: 2 people

.changeset/sweet-spoons-study.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-node': patch
+---
+
+fix: disable gzip and brotli when precompress=false

packages/adapter-node/index.d.ts

@@ -3,6 +3,7 @@ import './ambient.js';
 
 declare global {
 	const ENV_PREFIX: string;
+	const PRECOMPRESS: boolean;
 }
 
 interface AdapterOptions {

packages/adapter-node/index.js

@@ -104,7 +104,8 @@ export default function (opts = {}) {
 					MANIFEST: './server/manifest.js',
 					SERVER: './server/index.js',
 					SHIMS: './shims.js',
-					ENV_PREFIX: JSON.stringify(envPrefix)
+					ENV_PREFIX: JSON.stringify(envPrefix),
+					PRECOMPRESS: JSON.stringify(precompress)
 				}
 			});
 

packages/adapter-node/src/handler.js

@@ -12,6 +12,7 @@ import { env } from 'ENV';
 import { parse_as_bytes } from '../utils.js';
 
 /* global ENV_PREFIX */
+/* global PRECOMPRESS */
 
 const server = new Server(manifest);
 
@@ -47,8 +48,8 @@ function serve(path, client = false) {
 	return fs.existsSync(path)
 		? sirv(path, {
 				etag: true,
-				gzip: true,
-				brotli: true,
+				gzip: PRECOMPRESS,
+				brotli: PRECOMPRESS,
 				setHeaders: client
 					? (res, pathname) => {
 							// only apply to build directory, not e.g. version.json