Standalone Mode

You can also use the service without the WDIO testrunner, e.g. in a normal Node.js script.

The startWdioSession method accepts ElectronServiceCapabilities, which are the capabilities specified in a regular WDIO configuration.

The method creates a new WDIO session using your configuration and returns the WebdriverIO browser object:

import { startWdioSession } from '@wdio/electron-service';

const browser = await startWdioSession([{
  'browserName': 'electron', // you need to specify browserName
  'browserVersion': '33.2.1',
  'wdio:electronServiceOptions': {
    appBinaryPath: '/path/to/binary',
  },
  'goog:chromeOptions': {
    args: ['--disable-dev-shm-usage', '--disable-gpu', '--headless'],
  },
  'wdio:chromedriverOptions': {
    binary: '/path/to/chromedriver',
  },
}]);

const appName = await browser.electron.execute((electron) => electron.app.getName());

You can also use the createElectronCapabilities helper to build capabilities programmatically:

import { startWdioSession, createElectronCapabilities } from '@wdio/electron-service';

const caps = createElectronCapabilities({
  appBinaryPath: '/path/to/binary',
  appArgs: ['--disable-dev-shm-usage', '--disable-gpu', '--headless'],
});

const browser = await startWdioSession([caps]);

rootDir can be specified in the second (optional) ElectronServiceGlobalOptions parameter, which also accepts mocking preferences for the session:

const browser = await startWdioSession([
  { ... },
  {
    rootDir: '/path/to/dir',
    clearMocks: false,
    resetMocks: false,
    restoreMocks: true,
  }
]);

Log Capture in Standalone Mode

Standalone mode supports capturing console logs from both main and renderer processes. Unlike test runner mode where logs are forwarded to WDIO's logger, standalone mode writes logs to timestamped files.

Basic Log Capture

import { startWdioSession, cleanupWdioSession } from '@wdio/electron-service';

const browser = await startWdioSession([{
  browserName: 'electron',
  'wdio:electronServiceOptions': {
    appBinaryPath: '/path/to/binary',
    captureMainProcessLogs: true,
    captureRendererLogs: true,
    mainProcessLogLevel: 'info',
    rendererLogLevel: 'info',
    logDir: './test-logs'  // Required for standalone mode
  }
}]);

// Execute code in the main process - logs will be captured with [Electron:MainProcess] prefix
await browser.electron.execute((electron) => {
  console.log('Application initialized');
  console.info('App name:', electron.app.getName());
  console.warn('Using deprecated API in production build');
});

// Execute code in the renderer process - logs will be captured with [Electron:Renderer] prefix
await browser.execute(() => {
  console.log('Page loaded successfully');
  console.debug('Window dimensions:', window.innerWidth, window.innerHeight);
  console.error('Failed to fetch user data from API');
});

// Cleanup - closes log file
await cleanupWdioSession(browser);

Log File Output

Logs are written to {logDir}/wdio-{timestamp}.log:

2025-12-29T19:07:00.123Z INFO electron-service:service: [Electron:MainProcess] Application initialized
2025-12-29T19:07:00.234Z INFO electron-service:service: [Electron:MainProcess] App name: MyElectronApp
2025-12-29T19:07:00.456Z WARN electron-service:service: [Electron:MainProcess] Using deprecated API in production build
2025-12-29T19:07:01.123Z INFO electron-service:service: [Electron:Renderer] Page loaded successfully
2025-12-29T19:07:01.234Z DEBUG electron-service:service: [Electron:Renderer] Window dimensions: 1920 1080
2025-12-29T19:07:01.456Z ERROR electron-service:service: [Electron:Renderer] Failed to fetch user data from API

Log Level Filtering

Control which logs are captured by setting minimum log levels:

const browser = await startWdioSession([{
  browserName: 'electron',
  'wdio:electronServiceOptions': {
    appBinaryPath: '/path/to/binary',
    captureMainProcessLogs: true,
    mainProcessLogLevel: 'warn',  // Only warn and error
    captureRendererLogs: true,
    rendererLogLevel: 'debug',    // Debug, info, warn, and error
    logDir: './logs'
  }
}]);

Reading Logs Programmatically

import { readFileSync, readdirSync } from 'node:fs';
import { join } from 'node:path';

// After test execution
const logDir = './test-logs';
const logFiles = readdirSync(logDir).filter(f => f.startsWith('wdio-'));
const latestLog = logFiles.sort().reverse()[0];
const logContent = readFileSync(join(logDir, latestLog), 'utf-8');

// Parse or analyze logs
const mainProcessLogs = logContent
  .split('\n')
  .filter(line => line.includes('[Electron:MainProcess]'));

Important Notes

• logDir is required: Logs cannot be captured in standalone mode without specifying logDir
• Automatic cleanup: Call cleanupWdioSession() to ensure log files are properly closed
• CDP requirements:
  • Main process logs: Require the EnableNodeCliInspectArguments fuse to be enabled
  • Renderer process logs: Work independently via Puppeteer, no fuse requirement
  • If the CDP bridge is unavailable, only main process logs will be disabled (renderer logs continue to work)
• No WDIO logger: In standalone mode, logs are written to files, not forwarded to WDIO's logger