fix #5308

packages/kit/src/vite/build/build_server.js

@@ -1,7 +1,7 @@
 import fs from 'fs';
 import path from 'path';
 import { mkdirp, posixify } from '../../utils/filesystem.js';
-import { merge_vite_configs, resolve_entry } from '../utils.js';
+import { get_vite_config, merge_vite_configs, resolve_entry } from '../utils.js';
 import { load_template } from '../../core/config/index.js';
 import { get_runtime_path } from '../../core/utils.js';
 import { create_build, find_deps, get_default_config, remove_svelte_kit } from './utils.js';
@@ -104,7 +104,6 @@ export class Server {
 `;
 
 /**
- * @param {import('vite').UserConfig} vite_config
  * @param {{
  *   cwd: string;
  *   config: import('types').ValidatedConfig
@@ -115,7 +114,7 @@ export class Server {
  * }} options
  * @param {{ vite_manifest: import('vite').Manifest, assets: import('rollup').OutputAsset[] }} client
  */
-export async function build_server(vite_config, options, client) {
+export async function build_server(options, client) {
 	const { cwd, config, manifest_data, build_dir, output_dir, service_worker_entry_file } = options;
 
 	let hooks_file = resolve_entry(config.kit.files.hooks);
@@ -175,27 +174,11 @@ export async function build_server(vite_config, options, client) {
 		})
 	);
 
-	const default_config = {
-		build: {
-			target: 'node14.8'
-		},
-		ssr: {
-			// when developing against the Kit src code, we want to ensure that
-			// our dependencies are bundled so that apps don't need to install
-			// them as peerDependencies
-			noExternal: process.env.BUNDLED
-				? []
-				: Object.keys(
-						JSON.parse(fs.readFileSync(new URL('../../../package.json', import.meta.url), 'utf-8'))
-							.devDependencies
-				  )
-		}
-	};
+	const vite_config = await get_vite_config();
 
 	const merged_config = merge_vite_configs(
-		default_config,
-		vite_config,
-		get_default_config({ config, input, ssr: true, outDir: `${output_dir}/server` })
+		get_default_config({ config, input, ssr: true, outDir: `${output_dir}/server` }),
+		vite_config
 	);
 
 	remove_svelte_kit(merged_config);

packages/kit/src/vite/build/build_service_worker.js

@@ -1,12 +1,11 @@
 import fs from 'fs';
 import * as vite from 'vite';
 import { s } from '../../utils/misc.js';
-import { merge_vite_configs } from '../utils.js';
+import { get_vite_config, merge_vite_configs } from '../utils.js';
 import { normalize_path } from '../../utils/url.js';
 import { assets_base, remove_svelte_kit } from './utils.js';
 
 /**
- * @param {import('vite').UserConfig} vite_config
  * @param {{
  *   config: import('types').ValidatedConfig;
  *   manifest_data: import('types').ManifestData;
@@ -17,7 +16,6 @@ import { assets_base, remove_svelte_kit } from './utils.js';
  * @param {import('vite').Manifest} client_manifest
  */
 export async function build_service_worker(
-	vite_config,
 	{ config, manifest_data, output_dir, service_worker_entry_file },
 	prerendered,
 	client_manifest
@@ -67,6 +65,7 @@ export async function build_service_worker(
 			.trim()
 	);
 
+	const vite_config = await get_vite_config();
 	const merged_config = merge_vite_configs(vite_config, {
 		base: assets_base(config.kit),
 		build: {
@@ -83,6 +82,8 @@ export async function build_service_worker(
 			outDir: `${output_dir}/client`,
 			emptyOutDir: false
 		},
+		// @ts-expect-error
+		configFile: false,
 		resolve: {
 			alias: {
 				'$service-worker': service_worker,

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

@@ -1,3 +1,4 @@
+import fs from 'fs';
 import * as vite from 'vite';
 import { get_aliases } from '../utils.js';
 
@@ -77,13 +78,26 @@ export const get_default_config = function ({ config, input, ssr, outDir }) {
 				},
 				preserveEntrySignatures: 'strict'
 			},
-			ssr
+			ssr,
+			target: ssr ? 'node14.8' : undefined
 		},
 		// prevent Vite copying the contents of `config.kit.files.assets`,
 		// if it happens to be 'public' instead of 'static'
 		publicDir: false,
 		resolve: {
 			alias: get_aliases(config.kit)
+		},
+		// @ts-expect-error
+		ssr: {
+			// when developing against the Kit src code, we want to ensure that
+			// our dependencies are bundled so that apps don't need to install
+			// them as peerDependencies
+			noExternal: process.env.BUNDLED
+				? []
+				: Object.keys(
+						JSON.parse(fs.readFileSync(new URL('../../../package.json', import.meta.url), 'utf-8'))
+							.devDependencies
+				  )
 		}
 	};
 };

packages/kit/src/vite/index.js

@@ -84,6 +84,33 @@ function kit() {
 	 */
 	let paths;
 
+	function create_client_config() {
+		/** @type {Record<string, string>} */
+		const input = {
+			start: `${get_runtime_path(svelte_config.kit)}/client/start.js`
+		};
+
+		// This step is optional — Vite/Rollup will create the necessary chunks
+		// for everything regardless — but it means that entry chunks reflect
+		// their location in the source code, which is helpful for debugging
+		manifest_data.components.forEach((file) => {
+			const resolved = path.resolve(cwd, file);
+			const relative = path.relative(svelte_config.kit.files.routes, resolved);
+
+			const name = relative.startsWith('..')
+				? path.basename(file)
+				: posixify(path.join('pages', relative));
+			input[name] = resolved;
+		});
+
+		return get_default_config({
+			config: svelte_config,
+			input,
+			ssr: false,
+			outDir: `${paths.client_out_dir}/immutable`
+		});
+	}
+
 	return {
 		name: 'vite-plugin-svelte-kit',
 
@@ -104,33 +131,11 @@ function kit() {
 
 				manifest_data = sync.all(svelte_config).manifest_data;
 
-				/** @type {Record<string, string>} */
-				const input = {
-					start: `${get_runtime_path(svelte_config.kit)}/client/start.js`
-				};
-
-				// This step is optional — Vite/Rollup will create the necessary chunks
-				// for everything regardless — but it means that entry chunks reflect
-				// their location in the source code, which is helpful for debugging
-				manifest_data.components.forEach((file) => {
-					const resolved = path.resolve(cwd, file);
-					const relative = path.relative(svelte_config.kit.files.routes, resolved);
-
-					const name = relative.startsWith('..')
-						? path.basename(file)
-						: posixify(path.join('pages', relative));
-					input[name] = resolved;
-				});
-
-				const result = get_default_config({
-					config: svelte_config,
-					input,
-					ssr: false,
-					outDir: `${paths.client_out_dir}/immutable`
-				});
-
-				warn_overridden_config(config, result);
-				return result;
+				const new_config = create_client_config();
+
+				warn_overridden_config(config, new_config);
+
+				return new_config;
 			}
 
 			// dev and preview config can be shared
@@ -242,7 +247,7 @@ function kit() {
 
 			log.info('Building server');
 
-			const server = await build_server(vite_config, options, client);
+			const server = await build_server(options, client);
 
 			process.env.SVELTEKIT_SERVER_BUILD_COMPLETED = 'true';
 
@@ -255,12 +260,14 @@ function kit() {
 				server
 			};
 
-			const manifest = `export const manifest = ${generate_manifest({
-				build_data,
-				relative_path: '.',
-				routes: manifest_data.routes
-			})};\n`;
-			fs.writeFileSync(`${paths.output_dir}/server/manifest.js`, manifest);
+			fs.writeFileSync(
+				`${paths.output_dir}/server/manifest.js`,
+				`export const manifest = ${generate_manifest({
+					build_data,
+					relative_path: '.',
+					routes: manifest_data.routes
+				})};\n`
+			);
 
 			const static_files = manifest_data.assets.map((asset) => posixify(asset.file));
 
@@ -295,7 +302,7 @@ function kit() {
 
 				log.info('Building service worker');
 
-				await build_service_worker(vite_config, options, prerendered, client.vite_manifest);
+				await build_service_worker(options, prerendered, client.vite_manifest);
 			}
 
 			console.log(

packages/kit/src/vite/utils.js

@@ -1,7 +1,21 @@
 import fs from 'fs';
 import path from 'path';
+import { pathToFileURL } from 'url';
 import { get_runtime_path } from '../core/utils.js';
 
+/**
+ * @return {Promise<import('vite').UserConfig>}
+ */
+export async function get_vite_config() {
+	for (const file of ['vite.config.js', 'vite.config.mjs', 'vite.config.cjs']) {
+		if (fs.existsSync(file)) {
+			const config = await import(pathToFileURL(file).toString());
+			return config.default || config;
+		}
+	}
+	throw new Error('Could not find vite.config.js');
+}
+
 /**
  * @param {...import('vite').UserConfig} configs
  * @returns {import('vite').UserConfig}