Create a post bundle script for preview-api

To workaround vercel/next.js#57962

cc @ndelangen. Not sure we want to merge this but it gets us through the demo for now.

code/lib/preview-api/package.json

@@ -70,7 +70,8 @@
   "bundler": {
     "entries": [
       "./src/index.ts"
-    ]
+    ],
+    "post": "./rewrite-modules.ts"
   },
   "gitHead": "e6a7fd8a655c69780bc20b9749c2699e44beae17"
 }

code/lib/preview-api/rewrite-modules.ts

@@ -0,0 +1,30 @@
+/// <reference types="node" />
+
+// rewrite code from dist that triggers this bug: https://github.com/vercel/next.js/issues/57962
+import { join, relative } from 'path';
+import { cwd } from 'process';
+import { promises } from 'fs';
+
+const DIST = relative(cwd(), './dist');
+
+async function go() {
+  const filenames = await promises.readdir(DIST);
+
+  await Promise.all(
+    filenames.map(async (filename) => {
+      if (filename.endsWith('.mjs')) {
+        const fullFilename = join(DIST, filename);
+
+        const content = await promises.readFile(fullFilename, 'utf-8');
+
+        const newContent = content
+          .replace(/\(exports, module\)/g, '(exports, mod)')
+          .replace(/module.exports = /g, 'mod.exports = ');
+
+        await promises.writeFile(fullFilename, newContent);
+      }
+    })
+  );
+}
+
+go();