fix(vite-8): remove deprecated Rollup config options for Vite 8/Rolldown

packages/vinext/src/cli.ts

@@ -13,7 +13,11 @@
  * needed for most Next.js apps.
  */
 
-import vinext, { clientOutputConfig, clientTreeshakeConfig } from "./index.js";
+import vinext, {
+  getClientOutputConfig,
+  getClientTreeshakeConfig,
+  getViteMajorVersion,
+} from "./index.js";
 import { printBuildReport } from "./build/report.js";
 import path from "node:path";
 import fs from "node:fs";
@@ -350,6 +354,7 @@ async function buildApp() {
   console.log(`\n  vinext build  (Vite ${getViteVersion()})\n`);
 
   const isApp = hasAppDir();
+  const viteMajorVersion = getViteMajorVersion();
   // In verbose mode, skip the custom logger so raw Vite/Rollup output is shown.
   const logger = parsed.verbose
     ? vite.createLogger("info", { allowClearScreen: false })
@@ -387,8 +392,8 @@ async function buildApp() {
             ssrManifest: true,
             rollupOptions: {
               input: "virtual:vinext-client-entry",
-              output: clientOutputConfig,
-              treeshake: clientTreeshakeConfig,
+              output: getClientOutputConfig(viteMajorVersion),
+              treeshake: getClientTreeshakeConfig(viteMajorVersion),
             },
           },
         },

packages/vinext/src/index.ts

@@ -241,7 +241,7 @@ function extractStaticValue(node: any): unknown {
  * by a project that has Vite 8 — so we resolve from cwd, not from
  * the plugin's own location.
  */
-function getViteMajorVersion(): number {
+export function getViteMajorVersion(): number {
   try {
     const require = createRequire(path.join(process.cwd(), "package.json"));
     const vitePkg = require("vite/package.json");
@@ -525,6 +525,41 @@ const clientTreeshakeConfig = {
   moduleSideEffects: "no-external" as const,
 };
 
+/**
+ * Get Rollup-compatible output config for client builds.
+ * Returns config without Vite 8/Rolldown-incompatible options.
+ */
+function getClientOutputConfig(
+  viteVersion: number,
+): typeof clientOutputConfig | { manualChunks: typeof clientManualChunks } {
+  if (viteVersion >= 8) {
+    // Vite 8+ uses Rolldown which doesn't support experimentalMinChunkSize
+    return {
+      manualChunks: clientManualChunks,
+    };
+  }
+  // Vite 7 uses Rollup with experimentalMinChunkSize support
+  return clientOutputConfig;
+}
+
+/**
+ * Get Rollup-compatible treeshake config for client builds.
+ * Returns config without Vite 8/Rolldown-incompatible options.
+ */
+function getClientTreeshakeConfig(
+  viteVersion: number,
+): typeof clientTreeshakeConfig | { moduleSideEffects: "no-external" } {
+  if (viteVersion >= 8) {
+    // Vite 8+ uses Rolldown which doesn't support `preset` option
+    // moduleSideEffects is still supported in Rolldown
+    return {
+      moduleSideEffects: "no-external" as const,
+    };
+  }
+  // Vite 7 uses Rollup with preset support
+  return clientTreeshakeConfig;
+}
+
 type BuildManifestChunk = {
   file: string;
   isEntry?: boolean;
@@ -1232,15 +1267,17 @@ export default function vinext(options: VinextOptions = {}): PluginOption[] {
               // avoid leaking into RSC/SSR environments where
               // moduleSideEffects: 'no-external' could drop server packages
               // that rely on module-level side effects.
-              ...(!isSSR && !isMultiEnv ? { treeshake: clientTreeshakeConfig } : {}),
+              ...(!isSSR && !isMultiEnv
+                ? { treeshake: getClientTreeshakeConfig(viteMajorVersion) }
+                : {}),
               // Code-split client bundles: separate framework (React/ReactDOM),
               // vinext runtime (shims), and vendor packages into their own
               // chunks so pages only load the JS they need.
               // Only apply globally for standalone client builds (CLI Pages
               // Router). For multi-environment builds (App Router, Cloudflare),
               // manualChunks is set per-environment on the client env below
               // to avoid leaking into RSC/SSR environments.
-              ...(!isSSR && !isMultiEnv ? { output: clientOutputConfig } : {}),
+              ...(!isSSR && !isMultiEnv ? { output: getClientOutputConfig(viteMajorVersion) } : {}),
             },
           },
           // Let OPTIONS requests pass through Vite's CORS middleware to our
@@ -1444,8 +1481,8 @@ export default function vinext(options: VinextOptions = {}): PluginOption[] {
                 ...(hasCloudflarePlugin ? { manifest: true } : {}),
                 rollupOptions: {
                   input: { index: VIRTUAL_APP_BROWSER_ENTRY },
-                  output: clientOutputConfig,
-                  treeshake: clientTreeshakeConfig,
+                  output: getClientOutputConfig(viteMajorVersion),
+                  treeshake: getClientTreeshakeConfig(viteMajorVersion),
                 },
               },
             },
@@ -1463,8 +1500,8 @@ export default function vinext(options: VinextOptions = {}): PluginOption[] {
                 ssrManifest: true,
                 rollupOptions: {
                   input: { index: VIRTUAL_CLIENT_ENTRY },
-                  output: clientOutputConfig,
-                  treeshake: clientTreeshakeConfig,
+                  output: getClientOutputConfig(viteMajorVersion),
+                  treeshake: getClientTreeshakeConfig(viteMajorVersion),
                 },
               },
             },
@@ -3752,7 +3789,14 @@ export type {
 export type { NextConfig } from "./config/next-config.js";
 
 // Exported for CLI and testing
-export { clientManualChunks, clientOutputConfig, clientTreeshakeConfig, computeLazyChunks };
+export {
+  clientManualChunks,
+  clientOutputConfig,
+  clientTreeshakeConfig,
+  computeLazyChunks,
+  getClientOutputConfig,
+  getClientTreeshakeConfig,
+};
 export { augmentSsrManifestFromBundle as _augmentSsrManifestFromBundle };
 export { resolvePostcssStringPlugins as _resolvePostcssStringPlugins };
 export { _postcssCache };

tests/build-optimization.test.ts

@@ -8,11 +8,14 @@
 import { describe, it, expect, beforeEach, afterEach } from "vitest";
 import {
   clientManualChunks,
+  clientOutputConfig,
   clientTreeshakeConfig,
   computeLazyChunks,
   _augmentSsrManifestFromBundle,
   _stripServerExports,
   _asyncHooksStubPlugin,
+  getClientOutputConfig,
+  getClientTreeshakeConfig,
 } from "../packages/vinext/src/index.js";
 
 // The vinext config hook mutates process.env.NODE_ENV as a side effect (matching
@@ -47,6 +50,50 @@ describe("clientTreeshakeConfig", () => {
   });
 });
 
+// ─── getClientOutputConfig / getClientTreeshakeConfig ────────────────────────
+
+describe("getClientOutputConfig", () => {
+  it("returns full config with experimentalMinChunkSize for Vite 7", () => {
+    const result = getClientOutputConfig(7);
+    expect(result).toEqual(clientOutputConfig);
+    expect((result as any).experimentalMinChunkSize).toBe(10_000);
+    expect(result.manualChunks).toBe(clientManualChunks);
+  });
+
+  it("returns config without experimentalMinChunkSize for Vite 8", () => {
+    const result = getClientOutputConfig(8);
+    expect(result).toEqual({ manualChunks: clientManualChunks });
+    expect(result).not.toHaveProperty("experimentalMinChunkSize");
+  });
+
+  it("returns config without experimentalMinChunkSize for Vite 9", () => {
+    const result = getClientOutputConfig(9);
+    expect(result).toEqual({ manualChunks: clientManualChunks });
+    expect(result).not.toHaveProperty("experimentalMinChunkSize");
+  });
+});
+
+describe("getClientTreeshakeConfig", () => {
+  it("returns full config with preset for Vite 7", () => {
+    const result = getClientTreeshakeConfig(7);
+    expect(result).toEqual(clientTreeshakeConfig);
+    expect((result as any).preset).toBe("recommended");
+    expect(result.moduleSideEffects).toBe("no-external");
+  });
+
+  it("returns config without preset for Vite 8", () => {
+    const result = getClientTreeshakeConfig(8);
+    expect(result).toEqual({ moduleSideEffects: "no-external" });
+    expect(result).not.toHaveProperty("preset");
+  });
+
+  it("returns config without preset for Vite 9", () => {
+    const result = getClientTreeshakeConfig(9);
+    expect(result).toEqual({ moduleSideEffects: "no-external" });
+    expect(result).not.toHaveProperty("preset");
+  });
+});
+
 // ─── clientManualChunks ───────────────────────────────────────────────────────
 
 describe("clientManualChunks", () => {