fix: build not working in Es modules projects

src/node/build.ts

@@ -36,6 +36,7 @@ export async function build(cliOptions: Partial<ViteSSGOptions> = {}) {
     mock = false,
     entry = await detectEntry(root),
     formatting = null,
+    buildCjs = false,
     includedRoutes = DefaultIncludedRoutes,
     onBeforePageRender,
     onPageRendered,
@@ -72,10 +73,18 @@ export async function build(cliOptions: Partial<ViteSSGOptions> = {}) {
     mode: config.mode,
   })
 
+  let outputFile = join(ssgOut, 'main.js')
+  // rename to cjs extension
+  if (buildCjs === true) {
+    let pos = outputFile.lastIndexOf('.');
+    outputFile = outputFile.substr(0, pos < 0 ? outputFile.length : pos) + '.cjs';
+    await fs.rename(join(ssgOut, 'main.js'), outputFile);
+  }
+
   const ssrManifest: Manifest = JSON.parse(await fs.readFile(join(out, 'ssr-manifest.json'), 'utf-8'))
 
   // eslint-disable-next-line @typescript-eslint/no-var-requires
-  const { createApp } = require(join(ssgOut, 'main.js')) as { createApp: CreateAppFactory }
+  const { createApp } = require(outputFile) as { createApp: CreateAppFactory }
 
   let indexHTML = await fs.readFile(join(out, 'index.html'), 'utf-8')
 

src/types.ts

@@ -36,6 +36,15 @@ export interface ViteSSGOptions {
    */
   mode?: string
 
+  /**
+   * Uses .cjs file extension for temporary build file.
+   * This should be set to true for es-module environments
+   * with type: "module" set in package.json.
+   *
+   * @default false
+   */
+  buildCjs?: boolean
+
   /**
    * Custom functions to modified the routes to do the SSG.
    *