testing-electron

Testing Electron Applications

Extends core/rules/testing.mdc with Electron-specific testing patterns.

---

Main Process Testing

• Mock Electron APIs (app, BrowserWindow, ipcMain) for unit tests
• Test window creation, lifecycle, and configuration in isolation
• Test IPC handler registration and message routing
• Mock file system operations and native modules
• Test app lifecycle events (ready, window-all-closed, etc.)

Example:

import { BrowserWindow } from 'electron';

jest.mock('electron', () => ({
  BrowserWindow: jest.fn(),
  app: {
    on: jest.fn(),
    quit: jest.fn(),
  },
}));

---

Renderer Process Testing

• Mock window.electronAPI or contextBridge exports
• Avoid real Electron APIs in unit tests
• Test components independently of IPC
• Mock preload script exports
• Use JSDOM or similar for DOM testing

Example:

// Mock window.electronAPI
global.window.electronAPI = {
  send: jest.fn(),
  on: jest.fn(),
};

---

IPC Testing

• Handler validation: Test that IPC handlers validate input types and shapes
• Return values: Assert handlers return expected data structures
• Error handling: Test error scenarios and ensure proper error messages
• Bidirectional: Test both ipcMain.handle and ipcRenderer.invoke paths
• Security: Verify handlers check permissions before performing sensitive operations

Example:

// Test IPC handler
const result = await ipcMain.handlers.get('get-user')(event, userId);
expect(result).toMatchObject({ id: userId, name: expect.any(String) });

---

React + Electron Testing

• Custom hooks: Use @testing-library/react-hooks with renderHook and act
• Context providers: Wrap components under test with Electron context providers
• Electron APIs in hooks: Mock Electron APIs before invoking hooks that call them
• Event listeners: Test cleanup of IPC event listeners on unmount

Example:

import { renderHook } from '@testing-library/react-hooks';

const { result } = renderHook(() => useElectronStore(), {
  wrapper: ElectronProvider,
});