Common Issues

These are some common issues which others have encountered whilst using the service. For debugging tools and features, see the Debugging guide.

CDP bridge cannot be initialized: EnableNodeCliInspectArguments fuse is disabled

This warning appears when your Electron app has the EnableNodeCliInspectArguments fuse explicitly disabled. The CDP (Chrome DevTools Protocol) bridge relies on the --inspect flag to connect to Electron's main process, so when this fuse is disabled, the service cannot provide access to the main process APIs.

Impact

When this fuse is disabled:

❌ browser.electron.execute() - main process API access will not work
❌ browser.electron.mock() - mocking main process APIs will not work
❌ Main process log capture will not work (see Debugging - Log Capture Requirements)
✅ Renderer process testing continues to work normally
✅ Renderer process log capture continues to work (uses Puppeteer, not CDP bridge)
✅ Service initialization continues normally - no crashes or failures
✅ Clear error messages when attempting to use disabled APIs

Solution

Enable the fuse in your test builds. If you're disabling this fuse for production (which is good security practice), use conditional configuration:

import { flipFuses, FuseVersion, FuseV1Options } from '@electron/fuses';

await flipFuses(require('electron'), {
  version: FuseVersion.V1,
  [FuseV1Options.EnableNodeCliInspectArguments]: process.env.BUILD_FOR_TESTS === 'true',
  // ... other fuses
});

Then build with the environment variable, e.g.:

BUILD_FOR_TESTS=true npm run build  # for testing
npm run build                       # for production

See: Electron Fuses Documentation

DevToolsActivePort file doesn't exist

This is a Chromium error which may appear when using Docker or CI. Most of the "fixes" discussed online are based around passing different combinations of args to Chromium - you can set these via appArgs, though in most cases using xvfb has proven to be more effective; the service itself uses xvfb when running E2Es on Linux CI.

See this WDIO documentation page for instructions on how to set up xvfb.

Note: WebdriverIO 9.19.1+ is required for automatic Xvfb support via the autoXvfb configuration option. For legacy WDIO versions, you'll need to use external tools like xvfb-maybe or manually set up Xvfb.

Failed to create session. session not created: probably user data directory is already in use, please specify a unique value for --user-data-dir argument, or don't use --user-data-dir

This is another obscure Chromium error which, despite the message, is usually not fixed by providing a unique --user-data-dir value. In the Electron context this usually occurs when the Electron app crashes during or shortly after initialization. WDIO / ChromeDriver attempts to reconnect, starting a new electron instance, which attempts to use the same user-data-dir path. Whilst there may be other causes, on Linux this is often fixed with xvfb.

See this WDIO documentation page for instructions on how to set up xvfb.

All versions of Electron fail to open on Ubuntu 24.04+

See this issue for more details. This is caused by AppArmor restrictions on unprivileged user namespaces.

Alternative Solution

Manual AppArmor workaround: Run sysctl -w kernel.apparmor_restrict_unprivileged_userns=0 before running your tests. This command requires root privileges; if necessary, run it as the root user or use the sudo command.

TypeError: logger is not a function

Still applies in v10. The package was renamed from wdio-electron-service to @wdio/electron-service, but the import-time initialization order didn't change — the same workaround is needed.

This error occurs when importing the browser object directly at the top level of test files:

// ❌ This may cause "TypeError: logger is not a function"
import { browser } from "@wdio/electron-service";

describe("My Tests", () => {
  it("should work", async () => {
    await browser.electron.execute(/* ... */);
  });
});

The service's internal logger and other dependencies aren't fully initialized when the browser object is imported during the test file loading phase, before WebDriverIO services have completed their initialization.

The solution is to use dynamic import within a before hook to ensure the service is fully initialized:

// ✅ Correct approach - dynamic import in before hook
import type { Mock } from "@vitest/spy";
import { $, expect } from "@wdio/globals";
import type { browser as WdioBrowser } from "@wdio/electron-service";

let browser: typeof WdioBrowser;

describe("My Tests", () => {
  before(async () => {
    ({ browser } = await import("@wdio/electron-service"));
  });

  it("should work", async () => {
    await browser.electron.execute(/* ... */);
  });
});

Note for Service Contributors: If you're working within the desktop-mobile repository itself, you can use pnpm overrides to link to the workspace version:

{
  "pnpm": {
    "overrides": {
      "@wdio/electron-service": "workspace:*"
    }
  }
}

This allows direct imports to work reliably within the service's own repository, but this approach only applies when developing the service itself.

CDP bridge cannot be initialized: EnableNodeCliInspectArguments fuse is disabled​

Impact​

Solution​

DevToolsActivePort file doesn't exist​

Failed to create session. session not created: probably user data directory is already in use, please specify a unique value for --user-data-dir argument, or don't use --user-data-dir​

All versions of Electron fail to open on Ubuntu 24.04+​

Recommended Solution: Automatic AppArmor Profile​

Alternative Solution​

TypeError: logger is not a function​