[Fix] broken assets path

packages/kit/src/core/config/index.spec.js

@@ -121,6 +121,7 @@ const get_defaults = (prefix = '') => ({
 			pages: undefined
 		},
 		protocol: undefined,
+		relativeAssets: false,
 		router: undefined,
 		routes: undefined,
 		ssr: undefined,

packages/kit/src/core/config/options.js

@@ -304,6 +304,8 @@ const options = object(
 					`${keypath} has been removed. See https://github.com/sveltejs/kit/pull/3384 for details`
 			),
 
+			relativeAssets: boolean(false),
+
 			// TODO remove for 1.0
 			router: error((keypath) => `${keypath} has been moved to config.kit.browser.router`),
 

packages/kit/src/exports/vite/build/utils.js

@@ -110,7 +110,7 @@ export function get_default_build_config({ config, input, ssr, outDir }) {
 
 	return {
 		appType: 'custom',
-		base: ssr ? assets_base(config.kit) : './',
+		base: ssr ? assets_base(config.kit) : config.kit.relativeAssets === false ? '/' : './',
 		build: {
 			cssCodeSplit: true,
 			// don't use the default name to avoid collisions with 'static/manifest.json'
@@ -165,7 +165,7 @@ export function get_default_build_config({ config, input, ssr, outDir }) {
  * @returns {string}
  */
 export function assets_base(config) {
-	return (config.paths.assets || config.paths.base || '.') + '/';
+	return (config.paths.assets || config.paths.base) + (config.relativeAssets === false ? '/' : '.');
 }
 
 const method_names = new Set(['GET', 'HEAD', 'PUT', 'POST', 'DELETE', 'PATCH']);

packages/kit/types/index.d.ts

@@ -217,6 +217,7 @@ export interface KitConfig {
 		onError?: PrerenderOnErrorValue;
 		origin?: string;
 	};
+	relativeAssets?: boolean;
 	serviceWorker?: {
 		register?: boolean;
 		files?: (filepath: string) => boolean;