From d753c50088d2c492af678cb8aa68bb3ce3187819 Mon Sep 17 00:00:00 2001
From: Moti Zilberman <moti@meta.com>
Date: Mon, 2 Jun 2025 11:31:53 -0700
Subject: [PATCH] Bring RNDT shell to front when paused on breakpoint

Summary:
Changelog: [Internal]

Implements the first RNDT shell-specific feature based on https://github.com/facebook/react-native-devtools-frontend/pull/168 - namely, the ability for RNDT to foreground itself when certain events occur. This is most noticeable when pausing on a breakpoint.

Differential Revision: D75795689
---
 .../src/electron/MainInstanceEntryPoint.js    | 16 +++++++-
 .../debugger-shell/src/electron/preload.js    | 41 +++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 packages/debugger-shell/src/electron/preload.js

diff --git a/packages/debugger-shell/src/electron/MainInstanceEntryPoint.js b/packages/debugger-shell/src/electron/MainInstanceEntryPoint.js
index dcbecc8db3f3..9fe927e2ff20 100644
--- a/packages/debugger-shell/src/electron/MainInstanceEntryPoint.js
+++ b/packages/debugger-shell/src/electron/MainInstanceEntryPoint.js
@@ -9,7 +9,7 @@
  */
 
 // $FlowFixMe[unclear-type] We have no Flow types for the Electron API.
-const {BrowserWindow, app, shell} = require('electron') as any;
+const {BrowserWindow, app, shell, ipcMain} = require('electron') as any;
 const util = require('util');
 
 const windowMetadata = new WeakMap<
@@ -66,6 +66,7 @@ function handleLaunchArgs(argv: string[]) {
     height: 600,
     webPreferences: {
       partition: 'persist:react-native-devtools',
+      preload: require.resolve('./preload.js'),
     },
   });
 
@@ -102,3 +103,16 @@ app.whenReady().then(() => {
 app.on('window-all-closed', function () {
   app.quit();
 });
+
+ipcMain.on('bringToFront', (event, title) => {
+  const webContents = event.sender;
+  const win = BrowserWindow.fromWebContents(webContents);
+  if (win) {
+    win.focus();
+  }
+  if (process.platform === 'darwin') {
+    app.focus({
+      steal: true,
+    });
+  }
+});
diff --git a/packages/debugger-shell/src/electron/preload.js b/packages/debugger-shell/src/electron/preload.js
new file mode 100644
index 000000000000..22c4e0bbff8f
--- /dev/null
+++ b/packages/debugger-shell/src/electron/preload.js
@@ -0,0 +1,41 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+const {contextBridge, ipcRenderer} = require('electron');
+
+contextBridge.executeInMainWorld({
+  func: ipcDevTools => {
+    let didDecorateInspectorFrontendHostInstance = false;
+    // reactNativeDecorateInspectorFrontendHostInstance was introduced in
+    // https://github.com/facebook/react-native-devtools-frontend/pull/168
+    globalThis.reactNativeDecorateInspectorFrontendHostInstance =
+      InspectorFrontendHostInstance => {
+        didDecorateInspectorFrontendHostInstance = true;
+        InspectorFrontendHostInstance.bringToFront = () => {
+          ipcDevTools.bringToFront();
+        };
+      };
+
+    document.addEventListener('DOMContentLoaded', () => {
+      if (!didDecorateInspectorFrontendHostInstance) {
+        console.error(
+          'reactNativeDecorateInspectorFrontendHostInstance was not called at startup. ' +
+            'This version of the DevTools frontend may not be compatible with @react-native/debugger-shell.',
+        );
+      }
+    });
+  },
+  args: [
+    {
+      bringToFront() {
+        ipcRenderer.send('bringToFront');
+      },
+    },
+  ],
+});