fix: update from rolldown-vite to vite-8 beta

.changeset/nine-lizards-design.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/vite-plugin-svelte': patch
+---
+
+Update experimental support for rolldown-vite to vite 8 beta

.github/workflows/ci.yml

@@ -94,10 +94,10 @@ jobs:
             os: ubuntu-latest
             vite: 'baseline'
             svelte: 'baseline'
-          # future test with rolldown-vite
+          # future test with vite-8-beta
           - node: 24
             os: ubuntu-latest
-            vite: 'rolldown-vite'
+            vite: '8-beta'
             svelte: 'current'
     steps:
       - uses: actions/checkout@v5
@@ -128,17 +128,17 @@ jobs:
         run: |
           pnpm update -r --no-save svelte@5.0.0
           pnpm ls svelte
-      - name: update vite to rolldown-vite
-        if: matrix.vite == 'rolldown-vite'
+      - name: update vite to vite-8-beta
+        if: matrix.vite == '8-beta'
         run: |
-          pnpm update -r --no-save vite@npm:rolldown-vite@latest
-          pnpm ls rolldown-vite
+          pnpm update -r --no-save vite@^8.0.0-beta.0
+          pnpm ls vite
       - name: install playwright chromium
         run: pnpm playwright install chromium
       - name: run tests
         run: pnpm test
-      - name: check-types with rolldown-vite
-        if: matrix.vite == 'rolldown-vite'
+      - name: check-types with vite-8-beta
+        if: matrix.vite == '8-beta'
         run: pnpm check:types
       - name: archive tests temp directory
         if: failure()

packages/e2e-tests/_test_dependencies/svelte-simple/src/components/Dependency.svelte

@@ -1,7 +1,9 @@
 <script>
-	const label = 'dependency-import';
 	import * as cjsOnly from 'e2e-test-dep-cjs-only';
+	const label = 'dependency-import';
 	const { cjs } = cjsOnly;
+	// moving the following script close tag to column 0 triggers a bug in svelte sourcemap creation that prevents rolldown optimizer from processing the sourcemap
+	// TODO: move it back after fixed in svelte see https://github.com/sveltejs/svelte/pull/17167
 </script>
 
 <div id="dependency-import"><span class="label">{label}</span></div>

packages/e2e-tests/scan-deps/__tests__/scan-deps.spec.ts

@@ -1,15 +1,9 @@
-import { e2eServer, getText } from '~utils';
+import { getServerErrors, getText } from '~utils';
 import { describe, expect, it } from 'vitest';
 describe('vite import scan', () => {
 	it('should not fail to discover dependencies exported from script module', async () => {
 		// vite logs an error if scan fails but continues, so validate no errors logged
-		const errorLogs = e2eServer.logs.server.err.filter(
-			(line) =>
-				![
-					'Support for rolldown-vite in vite-plugin-svelte is experimental',
-					'See https://github.com/sveltejs/vite-plugin-svelte/issues/1143 for a list of known issues'
-				].some((ignore) => line.includes(ignore))
-		);
+		const errorLogs = getServerErrors();
 		expect(errorLogs.length, `unexpected errors:\n${errorLogs.join('\n')}`).toBe(0);
 	});
 	it('should work with exports from module context', async () => {

packages/e2e-tests/testUtils.ts

@@ -373,7 +373,7 @@ function filterMessages(arr) {
 	const excludes = [];
 	if (isRolldownVite) {
 		excludes.push(
-			'Support for rolldown-vite in vite-plugin-svelte is experimental',
+			'Support for vite 8 beta in vite-plugin-svelte is experimental',
 			'See https://github.com/sveltejs/vite-plugin-svelte/issues/1143'
 		);
 	}

packages/vite-plugin-svelte/src/plugins/configure.js

@@ -24,7 +24,7 @@ const { version: viteVersion, rolldownVersion } = vite;
 export function configure(api, inlineOptions) {
 	if (rolldownVersion) {
 		log.warn.once(
-			`!!! Support for rolldown-vite in vite-plugin-svelte is experimental (rolldown: ${rolldownVersion}, vite: ${viteVersion}) !!!
+			`!!! Support for vite 8 beta in vite-plugin-svelte is experimental (rolldown: ${rolldownVersion}, vite: ${viteVersion}) !!!
 			See https://github.com/sveltejs/vite-plugin-svelte/issues/1143 for a list of known issues and to report feedback.`.replace(
 				/\t+/g,
 				'\t'

packages/vite-plugin-svelte/src/plugins/setup-optimizer.js

@@ -43,7 +43,7 @@ export function setupOptimizer(api) {
 			// the added plugins are patched in configResolved below
 			if (rolldownVersion) {
 				//@ts-ignore rolldown types not finished
-				optimizeDeps.rollupOptions = {
+				optimizeDeps.rolldownOptions = {
 					plugins: [
 						placeholderRolldownOptimizerPlugin(optimizeSveltePluginName),
 						placeholderRolldownOptimizerPlugin(optimizeSvelteModulePluginName)
@@ -65,7 +65,7 @@ export function setupOptimizer(api) {
 			if (rolldownVersion) {
 				const plugins =
 					// @ts-expect-error not typed
-					optimizeDeps.rollupOptions?.plugins?.filter((p) =>
+					optimizeDeps.rolldownOptions?.plugins?.filter((p) =>
 						[optimizeSveltePluginName, optimizeSvelteModulePluginName].includes(p.name)
 					) ?? [];
 				for (const plugin of plugins) {

packages/vite-plugin-svelte/src/types/compile.d.ts

@@ -21,7 +21,7 @@ export interface Code {
 	map?: any;
 	dependencies?: any[];
 	hasGlobal?: boolean;
-	moduleType?: string; //rolldown-vite
+	moduleType?: string; //vite-8 beta
 	meta?: {
 		vite?: CustomPluginOptionsVite;
 	};

packages/vite-plugin-svelte/src/utils/options.js

@@ -423,9 +423,9 @@ function validateViteConfig(extraViteConfig, config, options) {
 	if (rolldownVersion && isBuild) {
 		// read user config inlineConst value
 		const inlineConst =
-			//@ts-ignore optimization only exists in rolldown-vite
+			//@ts-ignore optimization only exists in vite-8 beta
 			config.build?.rolldownOptions?.optimization?.inlineConst ??
-			//@ts-ignore optimization only exists in rolldown-vite
+			//@ts-ignore optimization only exists in vite-8 beta
 			config.build?.rollupOptions?.optimization?.inlineConst;
 
 		if (inlineConst === false) {