Electron Driver

Electron Driver Skill

The standard tool for End-to-End (E2E) Verification of Electron Applications.

Use this skill when you need to:

• Verify UI functionality (clicking buttons, checking text, form submission).
• Run automated regression tests on a packaged or local Electron app.
• Drive the application to reproduce bugs or set up state.
• Inspect the DOM and console of a running Electron process.

Supports two robust modes: Launch (Clean E2E Test) and Attach (Live Debugging).

• Launch: Start a new Electron instance with a controlled environment.
• Attach: Connect to an existing process via CDP (requires --remote-debugging-port).
• Inspect: Smartly find the main window (ignoring DevTools).
• Interact: Click, type, and verify using modern Playwright Locators.

Integration with e2e and tdd

electron-driver is the Electron-specific execution backend in the testing stack:

1. $tdd validates core logic and IPC units first.
2. $e2e defines end-user journey scenarios.
3. $electron-driver executes those scenarios against real Electron runtime windows/processes.

Use this skill when $e2e detects Electron context or when desktop-runtime debugging is required.

Prerequisites

1. Playwright: npm install playwright-core (locally preferred) or npm install -g playwright-core.
2. Electron Executable:
   • For Launch: Path to the Electron executable (e.g., node_modules/.bin/electron or the packaged app).
   • For Attach: The target app MUST be running with --remote-debugging-port=<port>.

Strategy Selection

Usage

1. Launch Mode (Recommended)

Create a script that launches the app.

File: test-driver.cjs (Use .cjs to avoid ESM/CJS issues)

const { _electron: electron } = require('playwright-core');

(async () => {
  // Launch the app
  // args: pointing to main.js or the packaged app executable
  const app = await electron.launch({
    args: ['.'], // Or path to executable
    env: { ...process.env, NODE_ENV: 'development' }
  });

  try {
    // Smart Window Find (ignoring DevTools)
    const page = await app.firstWindow();
    if (page.url().startsWith('devtools://')) {
       // Loop to find real window if first one is devtools
       // (Logic typically handled by waiting for first non-devtools window)
    }
    
    console.log(`Title: ${await page.title()}`);

    // --- ACTION LOGIC ---
    // Modern Locator API
    await page.getByRole('button', { name: 'Login' }).click();
    await expect(page.getByText('Welcome')).toBeVisible(); // requires @playwright/test runner or stand-alone expect
    
    // Simple wait (if not using expect)
    await page.locator('.status').waitFor();
    // --------------------

  } catch (err) {
    console.error(err);
  } finally {
    // Close app
    await app.close();
  }
})();

2. Attach Mode (Debugging)

Pre-check: Ensure app is running with --remote-debugging-port=9222 (or check console for actual port).

File: attach-driver.cjs

const { chromium } = require('playwright-core');

(async () => {
  try {
    // Connect to CDP
    const browser = await chromium.connectOverCDP('http://localhost:9222');
    
    // Find the right page (Filter out DevTools)
    const context = browser.contexts()[0];
    const pages = context.pages();
    const page = pages.find(p => !p.url().startsWith('devtools://'));

    if (!page) throw new Error('No valid app window found');

    // --- ACTION LOGIC ---
    await page.locator('#submit-btn').click();
    // --------------------

    await browser.close(); // Disconnects (does not kill app)
  } catch (e) {
    console.error(e);
  }
})();

Playwright Modern Cheatsheet

• Locators (Preferred):
  • page.getByRole('button', { name: 'Save' })
  • page.getByText('Hello World')
  • page.getByPlaceholder('Email')
  • page.locator('.css-class')
• Actions:
  • await locator.click()
  • await locator.fill('text')
• Waiting:
  • ❌ await page.waitForSelector(...) (Old)
  • ✅ await locator.waitFor() (Explicit)
  • ✅ await locator.click() (Auto-waits)

Troubleshooting

• ESM Error: SyntaxError: Cannot use import statement... -> Save file as .mjs or change project type. Recommendation: Always save temp scripts as .cjs and use require.
• DevTools Window: If the script interacts with the inspector instead of the app, check the window filtering logic.
• Port Conflict: If 9222 is busy, try a different port in Launch args or Attach URL.