Jest E2E Testing Framework

A powerful Jest + Puppeteer E2E testing framework with built-in device automation, data builders, and CLI.

🚀 Features

• Easy Setup: Get started with E2E testing in minutes
• Device Automation: Built-in browser automation with simple API
• Data Builders: Flexible test data generation with inheritance
• CLI Tool: Comprehensive command-line interface
• Step Logging: Real-time test step tracking
• Single Test Enforcement: One test per file for better organization
• ES6 Module Support: Modern JavaScript syntax
• Headless & Visible Modes: Perfect for CI/CD and local development

📦 Installation

Global Installation (Recommended)

npm install -g jest-e2e@latest

Project Installation

npm install jest-e2e@latest
npx jest-e2e --help

🏃‍♂️ Quick Start

1. Install and Initialize

mkdir my-e2e-tests
cd my-e2e-tests
npm init -y
npm install jest-e2e@latest

# Just run it - auto-initializes with examples on first run
npx jest-e2e

2. That's it! 🎉

The framework automatically:

• ✅ Detects it's your first run
• ✅ Updates your package.json with ES module support and Jest configuration
• ✅ Adds helpful npm scripts (npm run jest-e2e, npm run jest-e2e:visible, etc.)
• ✅ Creates __tests__/, databuilders/, and config/ directories
• ✅ Copies example tests and configuration files
• ✅ Sets up global access to Jest E2E functions
• ✅ Installs required dependencies automatically
• ✅ Runs the example tests to show you it works

3. Use the New npm Scripts

After initialization, you can use these convenient scripts:

# Run all E2E tests (headless)
npm run jest-e2e

# Run with visible browser for debugging  
npm run jest-e2e:visible

# Run in watch mode
npm run jest-e2e:watch

# Or use the CLI directly with more options
npx jest-e2e --repl

4. Customize for Your App

Edit the example tests in __tests__/:

// __tests__/my-login-test-e2e.js
test('User can login successfully', async () => {
  const { device } = await E2ESetup();
  const { userEmail, userPassword } = getTestData();

  await device.navigate('https://your-app.com/login');  // 👈 Change URL
  await device.fill('#email', userEmail);              // 👈 Update selectors
  await device.fill('#password', userPassword);
  await device.click('#login-button');

  await device.waitForSelector('.dashboard');
  expect(await device.getInnerText('.welcome')).toContain('Welcome');
});

🎯 CLI Usage

jest-e2e [test_name] [options]

Options

• --useLocalBrowser true - Run with visible browser
• --repl - Keep browser open after test completion
• --debug - Enable debug mode
• --watch - Watch mode for development
• --verbose - Detailed output
• --timeout <ms> - Custom timeout (default: 30000)
• --slowmo <ms> - Add delay between actions
• --screenshot - Take screenshots on failure
• --silent - No step logging
• --help - Show help

Examples

# Run all tests in headless mode
jest-e2e

# Run specific test with visible browser
jest-e2e login-success --useLocalBrowser true

# Debug mode with step logging
jest-e2e payment-flow --debug --verbose

# Keep browser open for inspection
jest-e2e checkout-process --repl

# Slow motion for demonstrations
jest-e2e user-journey --slowmo 500 --useLocalBrowser true

🔧 API Reference

E2ESetup()

Main setup function that configures test environment with data builders and devices:

const { getTestData, getDevices } = E2ESetup({
  databuilder: AgentTestDataBuilder(),
  devices: {
    device: createChromeE2EApi({}),
  },
});

// Use in your tests
const { device } = getDevices();
const { userEmail, userPassword } = getTestData();

Device API

Built-in browser automation methods:

// Navigation
await device.navigate(url);
await device.goBack();
await device.refresh();

// Interactions
await device.click(selector);
await device.fill(selector, value);
await device.select(selector, value);
await device.hover(selector);

// Waiting
await device.waitForSelector(selector);
await device.waitForTimeout(ms);

// Information
const text = await device.getInnerText(selector);
const value = await device.getValue(selector);
const isVisible = await device.isVisible(selector);

Data Builders

Generate test data with inheritance:

// Import in your test files
import { AgentTestDataBuilder } from '../databuilders/agent-test-data-builder.js';

// Get test data (available globally in tests)
const { userEmail, userPassword } = getTestData();

// Custom data builder
export function myCustomDataBuilder() {
  return {
    ...baseDataBuilder(),
    customField: 'custom value',
    genImp() { return 'custom-implementation'; },
    getVersion() { return '1.0.0'; }
  };
}

Step Logging

Track test progress (available globally):

logStep('Navigating to login page');
logStep('Filling user credentials');
logStep('Submitting login form');

📁 Project Structure

After running npx jest-e2e for the first time, your project will have:

your-project/
├── __tests__/                     # Your E2E tests (auto-created with examples)
│   ├── example-login-success-e2e.js
│   ├── example-login-invalid-e2e.js
│   └── example-form-validation-e2e.js
├── databuilders/                  # Test data builders (auto-created)
│   ├── base-data-builder.js
│   └── agent-test-data-builder.js
├── config/                        # Configuration files (auto-created)
│   └── test-setup.js              # Global Jest E2E setup
├── jest-puppeteer.config.js       # Puppeteer configuration (auto-created)
└── package.json                   # Updated with ES modules & Jest config

Auto-Generated Files: The framework automatically creates all necessary files:

• Example Tests: Three example tests showing different patterns
• Data Builders: Base and example data builders for test data generation
• Configuration: Jest setup and Puppeteer configuration
• Package Configuration: Your package.json gets updated with proper ES module and Jest settings

🏗️ Custom Configuration

Automatic Package.json Updates

When you run npx jest-e2e for the first time, the framework automatically updates your package.json with:

{
  "type": "module",                    // Enables ES6 imports
  "scripts": {
    "test": "NODE_OPTIONS='--experimental-vm-modules --no-warnings' jest",
    "jest-e2e": "jest-e2e",                // Convenient E2E scripts
    "jest-e2e:visible": "jest-e2e --useLocalBrowser true",
    "jest-e2e:watch": "jest-e2e --watch"
  },
  "jest": {                            // Jest configuration for E2E
    "preset": "jest-puppeteer",
    "testMatch": ["**/*-e2e.js"],
    "testTimeout": 30000,
    "setupFilesAfterEnv": ["./config/test-setup.js"]
  },
  "devDependencies": {                 // Required testing dependencies
    "jest": "^29.7.0",
    "puppeteer": "^24.9.0",
    "jest-puppeteer": "^11.0.0"
  }
}

This automatic configuration eliminates the need for manual setup and ensures everything works out of the box!

Custom Puppeteer Configuration

Create jest-puppeteer.config.js:

export default {
  launch: {
    headless: process.env.CI === 'true',
    defaultViewport: { width: 1280, height: 720 },
    args: ['--no-sandbox', '--disable-setuid-sandbox']
  },
  server: {
    command: 'npm start',
    port: 3000,
    launchTimeout: 10000
  }
};

🎯 Writing Tests

Basic Test Structure

Since Jest E2E functions are globally available, you can write tests without imports:

/* eslint-disable no-undef */
"use strict";

// Import your specific data builders
import { AgentTestDataBuilder } from '../databuilders/agent-test-data-builder.js';

const { getTestData, getDevices } = E2ESetup({
  databuilder: AgentTestDataBuilder(),
  devices: {
    device: createChromeE2EApi({}),
  },
});

test("User can complete checkout", async () => {
  const { device } = getDevices();
  const { userEmail, userPassword } = getTestData();

  logStep('Navigate to login page');
  await device.navigate("https://your-app.com/login");

  logStep('Fill login credentials');
  await device.type("#email", userEmail);
  await device.type("#password", userPassword);

  logStep('Submit login form');
  await device.click("#login-button");

  // Verify success
  await device.expect("body").toContain("Dashboard");
});

Single Test Rule

Each test file must contain exactly one test function:

// ✅ Good - one test per file
test('User can complete checkout', async () => {
  // test implementation
});

// ❌ Bad - multiple tests in one file
test('Test 1', async () => {});
test('Test 2', async () => {}); // This will throw an error

Test File Naming

Use -e2e.js suffix for test files:

• login-success-e2e.js
• user-registration-e2e.js
• payment-flow-e2e.js

Data Builder Pattern

// databuilders/user-data-builder.js
export function userDataBuilder() {
  return {
    ...baseDataBuilder(), // Available globally
    userEmail: 'test@example.com',
    userPassword: 'password123',
    userFullName: 'Test User',

    genImp() {
      return 'user-builder-v1';
    },

    getVersion() {
      return '1.0.0';
    }
  };
}

🎯 Best Practices

1. Use Descriptive Test Names

test('User can login with valid credentials and access dashboard', async () => {
  // test implementation
});

2. Implement Page Object Pattern

class LoginPage {
  constructor(device) {
    this.device = device;
  }

  async login(email, password) {
    await this.device.type('#email', email);
    await this.device.type('#password', password);
    await this.device.click('#login-button');
  }
}

3. Use Step Logging

test('Complete user journey', async () => {
  const { device } = await E2ESetup();

  logStep('Navigate to homepage');
  await device.navigate('https://example.com');

  logStep('Click sign up button');
  await device.click('#signup');

  logStep('Fill registration form');
  // form filling...
});

🐛 Debugging

Visual Debugging

# Run with visible browser
jest-e2e my-test --useLocalBrowser true

# Keep browser open for inspection
jest-e2e my-test --repl

# Slow motion for better visibility
jest-e2e my-test --slowmo 1000 --useLocalBrowser true

Debug Mode

# Enable debug output
jest-e2e my-test --debug --verbose

Screenshots

# Take screenshots on failure
jest-e2e my-test --screenshot

📊 CI/CD Integration

GitHub Actions

name: E2E Tests
on: [push, pull_request]
jobs:
  e2e:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-node@v3
        with:
          node-version: '18'
      - run: npm install
      - run: npx jest-e2e --silent

GitLab CI

e2e_tests:
  image: node:18
  script:
    - npm install
    - npx jest-e2e --silent

🤝 Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📄 License

MIT License - see LICENSE file for details.

🆘 Support

• GitHub Issues
• Documentation
• CLI Reference
• Example Tests Guide

Made with ❤️ for the testing community