From 532162d2b5b0e05c1bca3d08e30c4e2b9387ac04 Mon Sep 17 00:00:00 2001
From: marekharanczyk <48673767+marekharanczyk@users.noreply.github.com>
Date: Thu, 15 Sep 2022 18:33:08 +0200
Subject: [PATCH] fix: EventEmitter is missing properties in sandbox preload
 script. (#35522)

---
 package.json                                 |  1 +
 spec/api-browser-window-spec.ts              | 20 ++++++++++++++++++++
 spec/fixtures/module/preload-eventemitter.js | 11 +++++++++++
 3 files changed, 32 insertions(+)
 create mode 100644 spec/fixtures/module/preload-eventemitter.js

diff --git a/package.json b/package.json
index cbeee0af1e81..aedaa5ba0ebd 100644
--- a/package.json
+++ b/package.json
@@ -45,6 +45,7 @@
     "eslint-plugin-node": "^11.1.0",
     "eslint-plugin-standard": "^4.0.1",
     "eslint-plugin-typescript": "^0.14.0",
+    "events": "^3.2.0",
     "express": "^4.16.4",
     "folder-hash": "^2.1.1",
     "fs-extra": "^9.0.1",
diff --git a/spec/api-browser-window-spec.ts b/spec/api-browser-window-spec.ts
index a925e6bf066d..de2330b92326 100644
--- a/spec/api-browser-window-spec.ts
+++ b/spec/api-browser-window-spec.ts
@@ -2970,6 +2970,26 @@ describe('BrowserWindow module', () => {
         expect(url).to.equal(expectedUrl);
       });
 
+      it('exposes full EventEmitter object to preload script', async () => {
+        const w = new BrowserWindow({
+          show: false,
+          webPreferences: {
+            sandbox: true,
+            preload: path.join(fixtures, 'module', 'preload-eventemitter.js')
+          }
+        });
+        w.loadURL('about:blank');
+        const [, rendererEventEmitterProperties] = await emittedOnce(ipcMain, 'answer');
+        const { EventEmitter } = require('events');
+        const emitter = new EventEmitter();
+        const browserEventEmitterProperties = [];
+        let currentObj = emitter;
+        do {
+          browserEventEmitterProperties.push(...Object.getOwnPropertyNames(currentObj));
+        } while ((currentObj = Object.getPrototypeOf(currentObj)));
+        expect(rendererEventEmitterProperties).to.deep.equal(browserEventEmitterProperties);
+      });
+
       it('should open windows in same domain with cross-scripting enabled', async () => {
         const w = new BrowserWindow({
           show: true,
diff --git a/spec/fixtures/module/preload-eventemitter.js b/spec/fixtures/module/preload-eventemitter.js
new file mode 100644
index 000000000000..26b5760de0a4
--- /dev/null
+++ b/spec/fixtures/module/preload-eventemitter.js
@@ -0,0 +1,11 @@
+(function () {
+  const { EventEmitter } = require('events');
+  const emitter = new EventEmitter();
+  const rendererEventEmitterProperties = [];
+  let currentObj = emitter;
+  do {
+    rendererEventEmitterProperties.push(...Object.getOwnPropertyNames(currentObj));
+  } while ((currentObj = Object.getPrototypeOf(currentObj)));
+  const { ipcRenderer } = require('electron');
+  ipcRenderer.send('answer', rendererEventEmitterProperties);
+})();