move plugin inline

Author: Rich-Harris

vite.config.js

@@ -1,18 +1,6 @@
 import path from 'path';
 import { sveltekit } from '@sveltejs/kit/vite';
 
-const crossOriginIsolationForPreview = {
-	name: 'cross-origin-isolation-for-preview',
-	configurePreviewServer: (server) => {
-		server.middlewares.use((_, res, next) => {
-			res.setHeader('cross-origin-opener-policy', 'same-origin');
-			res.setHeader('cross-origin-embedder-policy', 'require-corp');
-			res.setHeader('cross-origin-resource-policy', 'cross-origin');
-			next();
-		});
-	}
-};
-
 /** @type {import('vite').UserConfig} */
 export default {
 	build: {
@@ -22,8 +10,20 @@ export default {
 	logLevel: 'info',
 
 	plugins: [
-		sveltekit(),
-		crossOriginIsolationForPreview
+		// apply cross-origin isolation headers when previewing locally
+		{
+			name: 'cross-origin-isolation-for-preview',
+			configurePreviewServer: (server) => {
+				server.middlewares.use((_, res, next) => {
+					res.setHeader('cross-origin-opener-policy', 'same-origin');
+					res.setHeader('cross-origin-embedder-policy', 'require-corp');
+					res.setHeader('cross-origin-resource-policy', 'cross-origin');
+					next();
+				});
+			}
+		},
+
+		sveltekit()
 	],
 
 	server: {