electron-development

name	electron-development
description	"condition: Código não disponível para análise"

Electron Development

You are a senior Electron engineer specializing in secure, production-grade desktop application architecture. You have deep expertise in Electron's multi-process model, IPC security patterns, native OS integration, application packaging, code signing, and auto-update strategies.

Use this skill when

• Building new Electron desktop applications from scratch
• Securing an Electron app (contextIsolation, sandbox, CSP, nodeIntegration)
• Setting up IPC communication between main, renderer, and preload processes
• Packaging and distributing Electron apps with electron-builder or electron-forge
• Implementing auto-update with electron-updater
• Debugging main process issues or renderer crashes
• Managing multiple windows and application lifecycle
• Integrating native OS features (menus, tray, notifications, file system dialogs)
• Optimizing Electron app performance and bundle size

Do not use this skill when

• Building web-only applications without desktop distribution → use react-patterns, nextjs-best-practices
• Building Tauri apps (Rust-based desktop alternative) → use tauri-development if available
• Building Chrome extensions → use chrome-extension-developer
• Implementing deep backend/server logic → use nodejs-backend-patterns
• Building mobile apps → use react-native-architecture or flutter-expert

Instructions

1. Analyze the project structure and identify process boundaries.
2. Enforce security defaults: contextIsolation: true, nodeIntegration: false, sandbox: true.
3. Design IPC channels with explicit whitelisting in the preload script.
4. Implement, test, and build with appropriate tooling.
5. Validate against the Production Security Checklist before shipping.

---

Core Expertise Areas

1. Project Structure & Architecture

Recommended project layout:

my-electron-app/
├── package.json
├── electron-builder.yml        # or forge.config.ts
├── src/
│   ├── main/
│   │   ├── main.ts             # Main process entry
│   │   ├── ipc-handlers.ts     # IPC channel handlers
│   │   ├── menu.ts             # Application menu
│   │   ├── tray.ts             # System tray
│   │   └── updater.ts          # Auto-update logic
│   ├── preload/
│   │   └── preload.ts          # Bridge between main ↔ renderer
│   ├── renderer/
│   │   ├── index.html          # Entry HTML
│   │   ├── App.tsx             # UI root (React/Vue/Svelte/vanilla)
│   │   ├── components/
│   │   └── styles/
│   └── shared/
│       ├── constants.ts        # IPC channel names, shared enums
│       └── types.ts            # Shared TypeScript interfaces
├── resources/
│   ├── icon.png                # App icon (1024x1024)
│   └── entitlements.mac.plist  # macOS entitlements
├── tests/
│   ├── unit/
│   └── e2e/
└── tsconfig.json

Key architectural principles:

• Separate entry points: Main, preload, and renderer each have their own build configuration.
• Shared types, not shared modules: The shared/ directory contains only types, constants, and enums — never executable code imported across process boundaries.
• Keep main process lean: Main should orchestrate windows, handle IPC, and manage app lifecycle. Business logic belongs in the renderer or dedicated worker processes.

---

2. Process Model (Main / Renderer / Preload / Utility)

Electron runs multiple processes that are isolated by design:

Process	Role	Node.js Access	DOM Access
Main	App lifecycle, windows, native APIs, IPC hub	✅ Full	❌ None
Renderer	UI rendering, user interaction	❌ None (by default)	✅ Full
Preload	Secure bridge between main and renderer	✅ Limited (via contextBridge)	✅ Before page loads
Utility	CPU-intensive tasks, background work	✅ Full	❌ None

BrowserWindow with security defaults (MANDATORY):

import { BrowserWindow } from 'electron';
import path from 'node:path';

function createMainWindow(): BrowserWindow {
  const win = new BrowserWindow({
    width: 1200,
    height: 800,
    webPreferences: {
      // ── SECURITY DEFAULTS (NEVER CHANGE THESE) ──
      contextIsolation: true,     // Isolates preload from renderer context
      nodeIntegration: false,     // Prevents require() in renderer
      sandbox: true,              // OS-level process sandboxing
      
      // ── PRELOAD SCRIPT ──
      preload: path.join(__dirname, '../preload/preload.js'),
      
      // ── ADDITIONAL HARDENING ──
      webSecurity: true,          // Enforce same-origin policy
      allowRunningInsecureContent: false,
      experimentalFeatures: false,
    },
  });

  // Content Security Policy
  win.webContents.session.webRequest.onHeadersReceived((details, callback) => {
    ({
      : {
        ...details.,
        : [
          
        ],
      },
    });
  });

   win;
}

⚠️ CRITICAL: Never set nodeIntegration: true or contextIsolation: false in production. These settings expose the renderer to remote code execution (RCE) attacks through XSS vulnerabilities.

---

3. Secure IPC Communication

IPC is the only safe channel for communication between main and renderer processes. All IPC must flow through the preload script.

Preload script (contextBridge + explicit whitelisting):

// src/preload/preload.ts
import { contextBridge, ipcRenderer } from 'electron';

// ── WHITELIST: Only expose specific channels ──
const ALLOWED_SEND_CHANNELS = [
  'file:save',
  'file:open',
  'app:get-version',
  'dialog:show-open',
] as const;

const ALLOWED_RECEIVE_CHANNELS = [
  'file:saved',
  'file:opened',
  'app:version',
  'update:available',
  'update:progress',
  'update:downloaded',
  'update:error',
] as const;

type SendChannel = typeof ALLOWED_SEND_CHANNELS[number];
type ReceiveChannel = typeof ALLOWED_RECEIVE_CHANNELS[number];

contextBridge.exposeInMainWorld('electronAPI', {
  // One-way: renderer → main
  send: (channel: SendChannel, ...args: unknown[]) => {
    if (ALLOWED_SEND_CHANNELS.includes(channel)) {
      ipcRenderer.send(channel, ...args);
    }
  },

  
  :  {
     (.(channel)) {
       ipcRenderer.(channel, ...args);
    }
     .( ());
  },

  
  :  {
     (.(channel)) {
        = () => (...args);
      ipcRenderer.(channel, listener);
        ipcRenderer.(channel, listener);
    }
      {};
  },
});

Main process IPC handlers:

// src/main/ipc-handlers.ts
import { ipcMain, dialog, BrowserWindow } from 'electron';
import { readFile, writeFile } from 'node:fs/promises';

export function registerIpcHandlers(): void {
  // invoke() pattern: returns a value to the renderer
  ipcMain.handle('file:open', async () => {
    const { canceled, filePaths } = await dialog.showOpenDialog({
      properties: ['openFile'],
      filters: [{ name: 'Text Files', extensions: ['txt', 'md'] }],
    });
    
    if (canceled || filePaths.length === 0) return null;
    
    const content = await readFile(filePaths[0], 'utf-8');
    return { path: filePaths[0], content };
  });

  ipcMain.handle('file:save', async (_event, filePath: string, content: string) => {
    // VALIDATE INPUTS — never trust renderer data blindly
     ( filePath !==  ||  content !== ) {
        ();
    }
     (filePath, content, );
     { :  };
  });

  ipcMain.(,  {
     process..;
  });
}

Renderer usage (type-safe):

// src/renderer/App.tsx — or any renderer code
// The electronAPI is globally available via contextBridge

declare global {
  interface Window {
    electronAPI: {
      send: (channel: string, ...args: unknown[]) => void;
      invoke: (channel: string, ...args: unknown[]) => Promise<unknown>;
      on: (channel: string, callback: (...args: unknown[]) => void) => () => void;
    };
  }
}

// Open a file via IPC
async function openFile() {
  const result = await window.electronAPI.invoke('file:open');
  if (result) {
    console.log('File content:', result.content);
  }
}

// Subscribe to updates from main process
const unsubscribe = window..(,  {
  .(, version);
});

IPC Pattern Summary:

Pattern	Method	Use Case
Fire-and-forget	ipcRenderer.send() → ipcMain.on()	Logging, telemetry, non-critical notifications
Request/Response	ipcRenderer.invoke() → ipcMain.handle()	File operations, dialogs, data queries
Push to renderer	webContents.send() → ipcRenderer.on()	Progress updates, download status, auto-update

⚠️ Never use ipcRenderer.sendSync() in production — it blocks the renderer's event loop and freezes the UI.

---

4. Security Hardening

Production Security Checklist

── MANDATORY ──
[ ] contextIsolation: true
[ ] nodeIntegration: false
[ ] sandbox: true
[ ] webSecurity: true
[ ] allowRunningInsecureContent: false

── IPC ──
[ ] Preload uses contextBridge with explicit channel whitelisting
[ ] All IPC inputs are validated in the main process
[ ] No raw ipcRenderer exposed to renderer context
[ ] No use of ipcRenderer.sendSync()

── CONTENT ──
[ ] Content Security Policy (CSP) headers set on all windows
[ ] No use of eval(), new Function(), or innerHTML with untrusted data
[ ] Remote content (if any) loaded in separate BrowserView with restricted permissions
[ ] protocol.registerSchemesAsPrivileged() uses minimal permissions

── NAVIGATION ──
[ ] webContents 'will-navigate' event intercepted — block unexpected URLs
[ ] webContents 'new-window' event intercepted — prevent pop-up exploitation
[ ] No shell.openExternal() with unsanitized URLs

── PACKAGING ──
[ ] ASAR archive enabled (protects source from casual inspection)
[ ] No sensitive credentials or API keys bundled in the app
[ ] Code signing configured for both Windows and macOS
[ ] Auto-update uses HTTPS and verifies signatures

Preventing Navigation Hijacking:

// In main process, after creating a BrowserWindow
win.webContents.on('will-navigate', (event, url) => {
  const parsedUrl = new URL(url);
  // Only allow navigation within your app
  if (parsedUrl.origin !== 'http://localhost:5173') { // dev server
    event.preventDefault();
    console.warn(`Blocked navigation to: ${url}`);
  }
});

// Prevent new windows from being opened
win.webContents.setWindowOpenHandler(({ url }) => {
  try {
    const externalUrl = new URL(url);
    const allowedHosts = new Set(['example.com', 'docs.example.com']);

    // Never forward raw renderer-controlled URLs to the OS.
    // Unvalidated links can enable phishing or abuse platform URL handlers.
    if (externalUrl.protocol === 'https:' && allowedHosts.has(externalUrl.hostname)) {
      require('electron').shell.openExternal(externalUrl.toString());
    } else {
      .();
    }
  }  {
    .();
  }

   { :  }; 
});

Custom Protocol Registration (secure):

import { protocol } from 'electron';
import path from 'node:path';
import { readFile } from 'node:fs/promises';
import { URL } from 'node:url';

// Register a custom protocol for loading local assets securely
protocol.registerSchemesAsPrivileged([
  { scheme: 'app', privileges: { standard: true, secure: true, supportFetchAPI: true } },
]);

app.whenReady().then(() => {
  protocol.handle('app', async (request) => {
    const url = new URL(request.url);
    const baseDir = path.resolve(__dirname, '../renderer');
    // Strip the leading slash so path.resolve keeps baseDir as the root.
    const relativePath = path.normalize(decodeURIComponent(url.pathname).replace(/^[/\\]+/, ''));
    const filePath = path.resolve(baseDir, relativePath);

    if (!filePath.startsWith(baseDir)) {
        (, { :  });
    }

     data =  (filePath);
      (data);
  });
});

---

5. State Management Across Processes

Strategy 1: Main process as single source of truth (recommended for most apps)

// src/main/store.ts
import { app } from 'electron';
import { readFileSync, writeFileSync } from 'node:fs';
import path from 'node:path';

interface AppState {
  theme: 'light' | 'dark';
  recentFiles: string[];
  windowBounds: { x: number; y: number; width: number; height: number };
}

const DEFAULTS: AppState = {
  theme: 'light',
  recentFiles: [],
  windowBounds: { x: 0, y: 0, width: 1200, height: 800 },
};

class Store {
  private data: AppState;
  private filePath: string;

  constructor() {
    this.filePath = path.join(app.getPath(), );
    . = .();
  }

   ():  {
     {
       raw = (., );
       { ..., ....(raw) };
    }  {
       { ... };
    }
  }

  get<K  keyof >(: K): [K] {
     .[key];
  }

  set<K  keyof >(: K, : [K]):  {
    .[key] = value;
    (., .(., , ));
  }
}

  store =  ();

Strategy 2: electron-store (lightweight persistent storage)

import Store from 'electron-store';

const store = new Store({
  schema: {
    theme: { type: 'string', enum: ['light', 'dark'], default: 'light' },
    windowBounds: {
      type: 'object',
      properties: {
        width: { type: 'number', default: 1200 },
        height: { type: 'number', default: 800 },
      },
    },
  },
});

// Usage
store.set('theme', 'dark');
console.log(store.get('theme')); // 'dark'

Multi-window state synchronization:

// Main process: broadcast state changes to all windows
import { BrowserWindow } from 'electron';

function broadcastToAllWindows(channel: string, data: unknown): void {
  for (const win of BrowserWindow.getAllWindows()) {
    if (!win.isDestroyed()) {
      win.webContents.send(channel, data);
    }
  }
}

// When theme changes:
ipcMain.handle('settings:set-theme', (_event, theme: 'light' | 'dark') => {
  store.set('theme', theme);
  broadcastToAllWindows('settings:theme-changed', theme);
});

---

6. Build, Signing & Distribution

electron-builder Configuration

# electron-builder.yml
appId: com.mycompany.myapp
productName: My App
directories:
  output: dist
  buildResources: resources

files:
  - "out/**/*"       # compiled main + preload
  - "renderer/**/*"  # built renderer assets
  - "package.json"

asar: true
compression: maximum

# ── macOS ──
mac:
  category: public.app-category.developer-tools
  hardenedRuntime: true
  gatekeeperAssess: false
  entitlements: resources/entitlements.mac.plist
  entitlementsInherit: resources/entitlements.mac.plist
  target:
    - target: dmg
      arch: [x64, arm64]
    - target: zip
      arch: [x64, arm64]

# ── Windows ──
win:
  target:
    - target: 
       [, ]
   []


   
   
   



  
      
      
   
   



   
   
   

Code Signing

# macOS: requires Apple Developer certificate
# Set environment variables before building:
export CSC_LINK="path/to/Developer_ID_Application.p12"
export CSC_KEY_PASSWORD="your-password"

# Windows: requires EV or standard code signing certificate
# Set environment variables:
export WIN_CSC_LINK="path/to/code-signing.pfx"
export WIN_CSC_KEY_PASSWORD="your-password"

# Build signed app
npx electron-builder --mac --win --publish never

Auto-Update with electron-updater

// src/main/updater.ts
import { autoUpdater } from 'electron-updater';
import { BrowserWindow } from 'electron';
import log from 'electron-log';

export function setupAutoUpdater(mainWindow: BrowserWindow): void {
  autoUpdater.logger = log;
  autoUpdater.autoDownload = false; // Let user decide
  autoUpdater.autoInstallOnAppQuit = true;

  autoUpdater.on('update-available', (info) => {
    mainWindow.webContents.send('update:available', {
      version: info.version,
      releaseNotes: info.releaseNotes,
    });
  });

  autoUpdater.on('download-progress', (progress) => {
    mainWindow.webContents.send('update:progress', {
      percent: Math.round(progress.percent),
      bytesPerSecond: progress.bytesPerSecond,
    });
  });

  autoUpdater.on(,  {
    mainWindow..();
  });

  autoUpdater.(,  {
    log.(, err);
    mainWindow..(, err.);
  });

  
  ( autoUpdater.(),  *  *  * );
  autoUpdater.();
}


ipcMain.(,  autoUpdater.());
ipcMain.(,  autoUpdater.());

Bundle Size Optimization

• ✅ Use asar: true to package sources into a single archive
• ✅ Set compression: maximum in electron-builder config
• ✅ Exclude dev dependencies: "files" pattern should only include compiled output
• ✅ Use a bundler (Vite, webpack, esbuild) to tree-shake the renderer
• ✅ Audit node_modules shipped with the app — use electron-builder's files exclude patterns
• ✅ Consider @electron/rebuild for native modules instead of shipping prebuilt for all platforms
• ❌ Do NOT bundle the entire node_modules — only production dependencies

---

7. Developer Experience & Debugging

Development Setup with Hot Reload

// package.json scripts
{
  "scripts": {
    "dev": "concurrently \"npm run dev:renderer\" \"npm run dev:main\"",
    "dev:renderer": "vite",
    "dev:main": "electron-vite dev",
    "build": "electron-vite build",
    "start": "electron ."
  }
}

Recommended toolchain:

• electron-vite or electron-forge with Vite plugin — modern, fast HMR for renderer
• tsx or ts-node — for running TypeScript in main process during development
• concurrently — run renderer dev server + Electron simultaneously

Debugging the Main Process

// .vscode/launch.json
{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Debug Main Process",
      "type": "node",
      "request": "launch",
      "cwd": "${workspaceFolder}",
      "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron",
      "args": [".", "--remote-debugging-port=9223"],
      "sourceMaps": true,
      "outFiles": ["${workspaceFolder}/out/**/*.js"],
      "env": {
        "NODE_ENV": "development"
      }
    
  

Other debugging techniques:

// Enable DevTools only in development
if (process.env.NODE_ENV === 'development') {
  win.webContents.openDevTools({ mode: 'detach' });
}

// Inspect specific renderer processes from command line:
// electron . --inspect=5858 --remote-debugging-port=9223

Testing Strategy

Unit testing (Vitest / Jest):

// tests/unit/store.test.ts
import { describe, it, expect, vi } from 'vitest';

// Mock Electron modules for unit tests
vi.mock('electron', () => ({
  app: { getPath: () => '/tmp/test' },
}));

describe('Store', () => {
  it('returns default values for missing keys', () => {
    // Test store logic without Electron runtime
  });
});

E2E testing (Playwright + Electron):

// tests/e2e/app.spec.ts
import { test, expect, _electron as electron } from '@playwright/test';

test('app launches and shows main window', async () => {
  const app = await electron.launch({ args: ['.'] });
  const window = await app.firstWindow();

  // Wait for the app to fully load
  await window.waitForLoadState('domcontentloaded');

  const title = await window.title();
  expect(title).toBe('My App');

  // Take a screenshot for visual regression
  await window.screenshot({ path: 'tests/screenshots/main-window.png' });

  await app.close();
});

test('file open dialog works via IPC', async () => {
  const app = await electron.launch({ args: ['.'] });
  const window = await app.firstWindow();

  
   version =  .( () => {
     ..();
  });

  (version).();
   app.();
});

Playwright config for Electron:

// playwright.config.ts
import { defineConfig } from '@playwright/test';

export default defineConfig({
  testDir: './tests/e2e',
  timeout: 30_000,
  retries: 1,
  use: {
    trace: 'on-first-retry',
    screenshot: 'only-on-failure',
  },
});

---

Application Lifecycle Management

// src/main/main.ts
import { app, BrowserWindow } from 'electron';
import { registerIpcHandlers } from './ipc-handlers';
import { setupAutoUpdater } from './updater';
import { store } from './store';

let mainWindow: BrowserWindow | null = null;

app.whenReady().then(() => {
  registerIpcHandlers();
  mainWindow = createMainWindow();

  // Restore window bounds
  const bounds = store.get('windowBounds');
  if (bounds) mainWindow.setBounds(bounds);

  // Save window bounds on close
  mainWindow.on('close', () => {
    if (mainWindow) store.set('windowBounds', mainWindow.getBounds());
  });

  // Auto-update (only in production)
  if (app.isPackaged) {
    setupAutoUpdater(mainWindow);
  }

  // macOS: re-create window when dock icon is clicked
  app.on('activate', () => {
    if (BrowserWindow.(). === ) {
      mainWindow = ();
    }
  });
});


app.(,  {
   (process. !== ) {
    app.();
  }
});


app.(,  {
  contents.(,  {
    event.(); 
  });
});

---

Common Issue Diagnostics

White Screen on Launch

Symptoms: App starts but renderer shows a blank/white page Root causes: Incorrect loadFile/loadURL path, build output missing, CSP blocking scripts Solutions: Verify the path passed to win.loadFile() or win.loadURL() exists relative to the packaged app. Check DevTools console for CSP violations. In development, ensure the Vite/webpack dev server is running before Electron starts.

IPC Messages Not Received

Symptoms: invoke() hangs or send() has no effect Root causes: Channel name mismatch, preload not loaded, contextBridge not exposing the channel Solutions: Verify channel names match exactly between preload, main, and renderer. Confirm preload path is correct in webPreferences. Check that the channel is in the whitelist array.

Native Module Crashes

Symptoms: App crashes on startup with MODULE_NOT_FOUND or invalid ELF header Root causes: Native module compiled for wrong Electron/Node ABI version Solutions: Run npx @electron/rebuild after installing native modules. Ensure electron-builder is configured with the correct Electron version for rebuilding.

App Not Updating

Symptoms: autoUpdater.checkForUpdates() returns nothing or errors Root causes: Missing publish config, unsigned app (macOS), incorrect GitHub release assets Solutions: Verify publish section in electron-builder.yml. On macOS, app must be code-signed and notarized. Ensure the GitHub release contains the -mac.zip and latest-mac.yml (or equivalent Windows files).

Large Bundle Size (>200MB)

Symptoms: Built application is excessively large Root causes: Dev dependencies bundled, no tree-shaking, duplicate Electron binaries Solutions: Audit files patterns in electron-builder.yml. Use a bundler (Vite/esbuild) for the renderer. Check that devDependencies are not in dependencies. Use compression: maximum.

---

Best Practices

• ✅ Always set contextIsolation: true and nodeIntegration: false
• ✅ Always use contextBridge in preload with an explicit channel whitelist
• ✅ Always validate IPC inputs in the main process — treat renderer as untrusted
• ✅ Always use ipcMain.handle() / ipcRenderer.invoke() for request/response IPC
• ✅ Always configure Content Security Policy headers
• ✅ Always sanitize URLs before passing to shell.openExternal()
• ✅ Always code-sign your production builds
• ✅ Use Playwright with @playwright/test's Electron support for E2E tests
• ✅ Store user data in app.getPath('userData'), never in the app directory
• ❌ Never set nodeIntegration: true — this is the #1 Electron security vulnerability
• ❌ Never expose raw ipcRenderer or require() to the renderer context
• ❌ Never use remote module (deprecated and insecure)
• ❌ Never use ipcRenderer.sendSync() — it blocks the renderer event loop
• ❌ Never disable webSecurity in production
• ❌ Never load remote/untrusted content without a strict CSP and sandboxing

Limitations

• Electron bundles Chromium + Node.js, resulting in a minimum ~150MB app size — this is a fundamental trade-off of the framework
• Not suitable for apps where minimal install size is critical (consider Tauri instead)
• Single-window apps are simpler to architect; multi-window state synchronization requires careful IPC design
• Auto-update on Linux requires distributing via Snap, Flatpak, or custom mechanisms — electron-updater has limited Linux support
• macOS notarization requires an Apple Developer account ($99/year) and is mandatory for distribution outside the Mac App Store
• Debugging main process issues requires VS Code or Chrome DevTools via --inspect flag — there is no integrated debugger in Electron itself

Related Skills

• chrome-extension-developer — When building browser extensions instead of desktop apps (shares multi-process model concepts)
• docker-expert — When containerizing Electron's build pipeline or CI/CD
• react-patterns / react-best-practices — When using React for the renderer UI
• typescript-pro — When setting up advanced TypeScript configurations for multi-target builds
• nodejs-backend-patterns — When the main process needs complex backend logic
• github-actions-templates — When setting up CI/CD for cross-platform Electron builds

Diff History

• v00.33.0: Ingested from antigravity-awesome-skills community repo

---

Why This Skill Exists

Implement —

When to Use

Use this skill when the task requires electron development capabilities.

What If Fails

• condition: Código não disponível para análise