Electron 43: chrome.webRequest unusable in MV3 service workers (missing bindings resources)

ext-bg.js

// MV3 background service worker. In Chrome, chrome.webRequest is defined here
// (observational listeners work with the "webRequest" permission).
console.log('[repro] worker started');
console.log('[repro] typeof chrome.webRequest =', typeof chrome.webRequest);
console.log('[repro] typeof chrome.declarativeNetRequest =', typeof chrome.declarativeNetRequest);

chrome.webRequest.onBeforeRequest.addListener(
  (details) => {
    console.log('[repro] onBeforeRequest', details.url);
  },
  { urls: ['<all_urls>'] }
);

ext-manifest.json

{
  "manifest_version": 3,
  "name": "webrequest-mv3-repro",
  "version": "1.0.0",
  "permissions": ["webRequest"],
  "host_permissions": ["<all_urls>"],
  "background": {
    "service_worker": "bg.js"
  }
}

main.js

const { app, session } = require('electron');
const path = require('path');

app.whenReady().then(async () => {
  console.log('[repro] electron', process.versions.electron);
  try {
    const ext = await session.defaultSession.extensions.loadExtension(
      path.join(__dirname, 'ext'),
      { allowFileAccess: true }
    );
    console.log('[repro] loaded extension', ext.id, ext.manifest.manifest_version);
  } catch (err) {
    console.error('[repro] loadExtension failed:', err);
  }
  // give the service worker time to start and crash
  setTimeout(() => app.quit(), 4000);
});

output-excerpt.log

$ ELECTRON_ENABLE_LOGGING=1 electron main.js   # Electron 43.0.0, macOS arm64

[repro] electron 43.0.0
[repro] loaded extension kdngfbncpbgohjncjnnbcjboidooebdb 3
[39248:0705/062431.415189:INFO:CONSOLE:3] "[repro] worker started", source: chrome-extension://kdngfbncpbgohjncjnnbcjboidooebdb/bg.js (3)
[39279:0705/062431.418736:ERROR:extensions/renderer/resource_bundle_source_map.cc:72] NOTREACHED hit. Module resource registered as "webRequest" not found
[39279:0705/062431.425737:ERROR:extensions/renderer/resource_bundle_source_map.cc:72] NOTREACHED hit. Module resource registered as "webRequestEvent" not found
[39248:0705/062431.429316:INFO:CONSOLE:0] "(BLESSED_EXTENSION context for kdngfbncpbgohjncjnnbcjboidooebdb) No source for require(webRequest)", source:  (0)
[39248:0705/062431.429699:ERROR:extensions/browser/extensions_browser_client.cc:92] Extension Error:
  Message: (BLESSED_EXTENSION context for kdngfbncpbgohjncjnnbcjboidooebdb) No source for require(webRequest)
  Type:    RuntimeError
[39248:0705/062431.429728:INFO:CONSOLE:4] "[repro] typeof chrome.webRequest = object", source: chrome-extension://kdngfbncpbgohjncjnnbcjboidooebdb/bg.js (4)
[39248:0705/062431.429740:INFO:CONSOLE:5] "[repro] typeof chrome.declarativeNetRequest = undefined", source: chrome-extension://kdngfbncpbgohjncjnnbcjboidooebdb/bg.js (5)
[39248:0705/062431.429750:INFO:CONSOLE:0] "(BLESSED_EXTENSION context for kdngfbncpbgohjncjnnbcjboidooebdb) No source for require(webRequestEvent)", source:  (0)
[39248:0705/062431.441794:INFO:CONSOLE:7] "Uncaught TypeError: Cannot read properties of undefined (reading 'addListener')", source: chrome-extension://kdngfbncpbgohjncjnnbcjboidooebdb/bg.js (7)
[39248:0705/062431.441822:ERROR:extensions/browser/extensions_browser_client.cc:92] Extension Error:
  Message: Uncaught TypeError: Cannot read properties of undefined (reading 'addListener')
  Source:  chrome-extension://kdngfbncpbgohjncjnnbcjboidooebdb/bg.js (line 7)
  Type:    RuntimeError
[39248:0705/062431.449137:ERROR:extensions/browser/extensions_browser_client.cc:92] Extension Error:
  Message: Service worker registration failed. Status code: 15
  Source:  manifest.json
  Type:    ManifestError

REPRO.md

Repro: chrome.webRequest unusable in MV3 service workers (Electron 43.0.0)

Layout:

main.js            # electron main process
ext/manifest.json  # minimal MV3 extension
ext/bg.js          # background service worker

Run:

npm i electron@43.0.0
ELECTRON_ENABLE_LOGGING=1 npx electron main.js

Expected (Chrome behavior): the worker registers chrome.webRequest.onBeforeRequest (observational, no blocking) and stays alive.

Actual: the webRequest / webRequestEvent bindings module resources are missing from the resource bundle (NOTREACHED in extensions/renderer/resource_bundle_source_map.cc), so chrome.webRequest is an empty object, the worker throws at top level, and MV3 service worker registration fails with status code 15. See output-excerpt.log.

The same worker script runs fine in Chrome (chrome://extensions → Load unpacked).