Electron Dev

Electron Development Guide

This skill provides guidelines, patterns, and best practices for building production-grade Electron applications using Electron Vite and Electron Builder.

Quick Start

1. Core Rules: For detailed Electron development patterns and guidelines, refer to references/patterns.md within this skill.
2. Security: Always enable contextIsolation, sandbox, and disable nodeIntegration.
3. Architecture: Main process handles Node.js operations; renderer focuses on UI; preload bridges them securely.

Process Architecture

Main Process (Node.js Context)

The main process handles:

• Window creation and lifecycle
• File system and database operations
• IPC message handling
• Application-level events

Key guidelines:

• Use app.isReady() before creating windows
• Clean up resources on window.destroyed event
• Handle graceful shutdown with app.on('before-quit')

Renderer Process (Frontend Context)

The renderer process:

• Renders UI using web technologies (React, Vue, etc.)
• Communicates with main process via IPC only
• Never has direct access to Node.js APIs

Preload Script (Security Layer)

The preload script is the only bridge between renderer and main:

typescriptCopy code
import { contextBridge, ipcRenderer } from "electron";

contextBridge.exposeInMainWorld("electronAPI", {
  invoke: (channel: string, args?: unknown) => {
    const validChannels = ["db:query", "file:save", "app:close"];
    if (validChannels.includes(channel)) {
      return ipcRenderer.invoke(channel, args);
    }
    throw new Error(`Invalid IPC channel: ${channel}`);
  },
});

Security Checklist

Always configure webPreferences with these settings:

typescriptCopy code
webPreferences: {
  preload: path.join(__dirname, 'preload.js'),
  contextIsolation: true,        // REQUIRED
  enableRemoteModule: false,     // REQUIRED
  sandbox: true,                 // REQUIRED
  nodeIntegration: false,        // REQUIRED
  webSecurity: true,
}

IPC Communication

Main Process Handler

typescriptCopy code
ipcMain.handle("db:insert", async (event, data: unknown) => {
  if (!isValidInsertData(data)) {
    throw new Error("Invalid data");
  }
  return db.insert(data);
});

Security Rules

• Whitelist all IPC channels in preload script
• Validate all arguments in main process handlers
• Never trust user input from renderer
• Keep secrets in main process only

Configuration

electron-vite.config.ts

typescriptCopy code
import { defineConfig } from "electron-vite";

export default defineConfig({
  main: {
    build: {
      outDir: "dist/main",
      rollupOptions: {
        external: ["better-sqlite3", "native-module-name"],
      },
    },
  },
  preload: {
    build: { outDir: "dist/preload" },
  },
  renderer: {
    build: {
      outDir: "dist/renderer",
      rollupOptions: {
        output: {
          manualChunks: {
            vendor: ["react", "react-dom"],
          },
        },
      },
    },
  },
});

Native Modules

For native modules like better-sqlite3:

1. Exclude from rollup in electron-vite config
2. Include in extraResources in Electron Builder config
3. Use dynamic imports in main process
4. Rebuild for Electron using @electron/rebuild

Common Pitfalls

Never Do This

typescriptCopy code
// Exposing entire Node.js API
contextBridge.exposeInMainWorld("require", require);

// Not validating IPC messages
ipcMain.handle("dangerous", (event, data) => {
  fs.writeFileSync(data.path, data.content);
});

// Using __dirname in renderer
const imagePath = `${__dirname}/images/logo.png`;

Do This Instead

typescriptCopy code
// Whitelist specific channels
contextBridge.exposeInMainWorld("electronAPI", {
  invoke: (channel: string, args: unknown) => {
    if (!["safe:channel"].includes(channel)) throw new Error("Invalid");
    return ipcRenderer.invoke(channel, args);
  },
});

// Validate all arguments
ipcMain.handle("file:write", async (event, { path, content }) => {
  if (typeof path !== "string" || typeof content !== "string") {
    throw new TypeError("Invalid arguments");
  }
  // Safe to use
});

Validation Checklist

Before finishing a task involving Electron:

• Security settings enabled (contextIsolation, sandbox, no nodeIntegration)
• IPC channels whitelisted in preload script
• All IPC arguments validated in main process
• Native modules excluded from bundler and included in extraResources
• Secrets kept in main process only (not exposed to renderer)
• Run type checks (pnpm run typecheck) and tests (pnpm run test)

Troubleshooting

For detailed configuration examples and additional patterns, consult references/patterns.md.