"fix: Vite 7/Rolldown compatibility - convert shared/remote modules t…

…o ESM"

- Changed virtual modules from CJS (require + module.exports) to ESM
(await import + export)
- Changed file extensions from .js to .mjs to ensure ESM treatment by
bundlers
- This fixes the 'await is only valid in async functions' syntax error
when Rolldown
  wraps CJS modules in a function wrapper

Fixes #320"

src/virtualModules/virtualRemotes.ts

@@ -7,7 +7,8 @@ const cacheRemoteMap: {
 export const LOAD_REMOTE_TAG = '__loadRemote__';
 export function getRemoteVirtualModule(remote: string, command: string) {
   if (!cacheRemoteMap[remote]) {
-    cacheRemoteMap[remote] = new VirtualModule(remote, LOAD_REMOTE_TAG, '.js');
+    // Use .mjs extension to ensure ESM treatment by bundlers
+    cacheRemoteMap[remote] = new VirtualModule(remote, LOAD_REMOTE_TAG, '.mjs');
     cacheRemoteMap[remote].writeSync(generateRemotes(remote, command));
   }
   const virtual = cacheRemoteMap[remote];
@@ -24,10 +25,16 @@ export function getUsedRemotesMap() {
   return usedRemotesMap;
 }
 export function generateRemotes(id: string, command: string) {
+  // Generate ESM-compatible code to fix Vite 7/Rolldown compatibility
+  // The previous CJS code (require + module.exports + top-level await) caused syntax errors
+  // because Rolldown wraps CJS in a function where top-level await is invalid
   return `
-    const {initPromise} = require("${virtualRuntimeInitStatus.getImportId()}")
+    // Use dynamic import instead of require for ESM compatibility
+    const runtimeModule = await import("${virtualRuntimeInitStatus.getImportId()}")
+    const {initPromise} = runtimeModule
     const res = initPromise.then(runtime => runtime.loadRemote(${JSON.stringify(id)}))
     const exportModule = ${command !== 'build' ? '/*mf top-level-await placeholder replacement mf*/' : 'await '}initPromise.then(_ => res)
-    module.exports = exportModule
+    // Use ESM export instead of module.exports to avoid CJS wrapper issues
+    export default exportModule
   `;
 }

src/virtualModules/virtualRuntimeInitStatus.ts

@@ -1,8 +1,11 @@
 import VirtualModule from '../utils/VirtualModule';
-export const virtualRuntimeInitStatus = new VirtualModule('runtimeInit');
+// Use .mjs extension to ensure ESM treatment by bundlers
+export const virtualRuntimeInitStatus = new VirtualModule('runtimeInit', '__mf_v__', '.mjs');
 export function writeRuntimeInitStatus() {
   // Use globalThis singleton to ensure only one initPromise exists
   const globalKey = `__mf_init__${virtualRuntimeInitStatus.getImportId()}__`;
+  // Generate ESM-compatible code to fix Vite 7/Rolldown compatibility
+  // Use named ESM exports instead of module.exports for proper dynamic import support
   virtualRuntimeInitStatus.writeSync(`
     const globalKey = ${JSON.stringify(globalKey)}
     if (!globalThis[globalKey]) {
@@ -17,6 +20,9 @@ export function writeRuntimeInitStatus() {
         initReject
       }
     }
-    module.exports = globalThis[globalKey]
+    // Use ESM named exports instead of module.exports for compatibility with dynamic import()
+    export const initPromise = globalThis[globalKey].initPromise
+    export const initResolve = globalThis[globalKey].initResolve
+    export const initReject = globalThis[globalKey].initReject
     `);
 }

src/virtualModules/virtualShared_preBuild.ts

@@ -32,16 +32,22 @@ export const LOAD_SHARE_TAG = '__loadShare__';
 const loadShareCacheMap: Record<string, VirtualModule> = {};
 export function getLoadShareModulePath(pkg: string): string {
   if (!loadShareCacheMap[pkg])
-    loadShareCacheMap[pkg] = new VirtualModule(pkg, LOAD_SHARE_TAG, '.js');
+    // Use .mjs extension to ensure ESM treatment by bundlers
+    loadShareCacheMap[pkg] = new VirtualModule(pkg, LOAD_SHARE_TAG, '.mjs');
   const filepath = loadShareCacheMap[pkg].getPath();
   return filepath;
 }
 export function writeLoadShareModule(pkg: string, shareItem: ShareItem, command: string) {
+  // Generate ESM-compatible code to fix Vite 7/Rolldown compatibility
+  // The previous CJS code (require + module.exports + top-level await) caused syntax errors
+  // because Rolldown wraps CJS in a function where top-level await is invalid
   loadShareCacheMap[pkg].writeSync(`
     ;() => import(${JSON.stringify(getPreBuildLibImportId(pkg))}).catch(() => {});
     // dev uses dynamic import to separate chunks
     ${command !== 'build' ? `;() => import(${JSON.stringify(pkg)}).catch(() => {});` : ''}
-    const {initPromise} = require("${virtualRuntimeInitStatus.getImportId()}")
+    // Use dynamic import instead of require for ESM compatibility
+    const runtimeModule = await import("${virtualRuntimeInitStatus.getImportId()}")
+    const {initPromise} = runtimeModule
     const res = initPromise.then(runtime => runtime.loadShare(${JSON.stringify(pkg)}, {
       customShareInfo: {shareConfig:{
         singleton: ${shareItem.shareConfig.singleton},
@@ -50,6 +56,7 @@ export function writeLoadShareModule(pkg: string, shareItem: ShareItem, command:
       }}
     }))
     const exportModule = ${command !== 'build' ? '/*mf top-level-await placeholder replacement mf*/' : 'await '}res.then(factory => factory())
-    module.exports = exportModule
+    // Use ESM export instead of module.exports to avoid CJS wrapper issues
+    export default exportModule
   `);
 }