Include code cache for preload bundle

Co-authored-by: Scott Nonnenberg <scott@signal.org>

ts/scripts/generate-preload-cache.preload.ts

@@ -0,0 +1,29 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { Module } from 'node:module';
+import { readFile, writeFile } from 'node:fs/promises';
+import { join } from 'node:path';
+import { Script } from 'node:vm';
+import { ipcRenderer } from 'electron';
+
+ipcRenderer.on('compile', async () => {
+  try {
+    const sourceFile = join(__dirname, '..', '..', 'preload.bundle.js');
+    const outFile = sourceFile.replace(/\.js$/, '');
+
+    const source = await readFile(sourceFile, 'utf8');
+    const script = new Script(Module.wrap(source), {
+      filename: 'preload.bundle.js',
+      produceCachedData: true,
+    });
+    if (!script.cachedDataProduced || !script.cachedData) {
+      throw new Error('Cached data not produced');
+    }
+
+    await writeFile(`${outFile}.cache`, script.cachedData);
+    await ipcRenderer.invoke('done');
+  } catch (error) {
+    await ipcRenderer.invoke('error', error);
+  }
+});