E2E Test Generation

Generate comprehensive end-to-end tests for critical user flows.

Table of Contents

1. Supported Frameworks
2. Workflow
3. Playwright with Page Object Model
4. REST Assured (Java)
5. Critical User Flows Checklist
6. Flaky Test Management
7. Best Practices
8. CI/CD Integration
9. Configuration
10. Artifact Management

Supported Frameworks

React/Vue/Angular (Playwright - Recommended)

# Install
npm init playwright@latest

# Run tests
npx playwright test
npx playwright test --ui
npx playwright codegen localhost:3000

# Debug
npx playwright test --debug
npx playwright show-report

Java API (REST Assured + Testcontainers)

mvn test -Dtest=*E2ETest

Workflow

1. Identify Flow

What user journey needs testing? Examples:

• User registration → Email verification → Login
• Product search → Add to cart → Checkout → Payment
• Admin: Create item → Edit → Delete

2. Define Steps

List all user actions and expected outcomes:

1. Navigate to /register
2. Fill form (valid data)
3. Submit
4. Verify redirect to /verify-email
5. Check email sent (mock)
6. Click verification link
7. Verify redirect to /dashboard

3. Write Test

Playwright with Page Object Model

// pages/RegisterPage.ts
export class RegisterPage {
  constructor(page) {
    this.page = page
    this.email = page.locator('[data-testid="email"]')
    this.password = page.locator('[data-testid="password"]')
    this.submit = page.locator('[data-testid="submit"]')
  }
  
  async goto() {
    await this.page.goto('/register')
  }
  
  async register(email, password) {
    await this.email.fill(email)
    await this.password.fill(password)
    await this.submit.click()
  }
}

// tests/auth/register.spec.ts
import { test, expect } from '@playwright/test'
import { RegisterPage } from '../pages/RegisterPage'

test.describe('User Registration', () => {
  test('should register with valid data', async ({ page }) => {
    const registerPage = new RegisterPage(page)
    
    // Arrange
    await registerPage.goto()
    
    // Act
    await registerPage.register('test@example.com', 'SecurePass123!')
    
    // Assert
    await expect(page).toHaveURL('/verify-email')
    await expect(page.locator('[data-testid="success"]')).toBeVisible()
    
    // Artifact
    await page.screenshot({ path: 'artifacts/register-success.png' })
  })
})

REST Assured (Java)

@Testcontainers
class UserE2ETest {
    
    @Container
    static PostgreSQLContainer<?> postgres = 
        new PostgreSQLContainer<>("postgres:16");
    
    @Test
    void fullUserLifecycle() {
        // 1. Create user
        String userId = given()
            .contentType(ContentType.JSON)
            .body("{\"email\":\"test@example.com\",\"name\":\"Test\"}")
            .post("/api/users")
            .then()
            .statusCode(201)
            .extract().jsonPath().getString("id");
        
        // 2. Verify created
        given()
            .get("/api/users/" + userId)
            .then()
            .statusCode(200)
            .body("email", equalTo("test@example.com"));
        
        // 3. Update user
        given()
            .contentType(ContentType.JSON)
            .body("{\"name\":\"Updated\"}")
            .put("/api/users/" + userId)
            .then()
            .statusCode(200);
        
        // 4. Delete user
        given()
            .delete("/api/users/" + userId)
            .then()
            .statusCode(204);
        
        // 5. Verify deleted
        given()
            .get("/api/users/" + userId)
            .then()
            .statusCode(404);
    }
}

4. Run & Verify

# Run all tests
npx playwright test

# Run with trace for debugging
npx playwright test --trace on

# Run specific test
npx playwright test tests/auth/register.spec.ts

Critical User Flows Checklist

Authentication

• User registration (happy path)
• Registration validation errors
• Login with valid credentials
• Login with invalid credentials
• Password reset flow
• Logout

Core Features

• Main CRUD operations (Create, Read, Update, Delete)
• Search functionality
• Filtering and sorting
• Pagination
• File uploads

Payment (if applicable)

• Add payment method
• Process payment
• Handle payment failure
• Refund flow

Error Handling

• 404 page
• 500 error handling
• Network failure recovery
• Form validation errors

Edge Cases

• Empty states (no data)
• Long text inputs
• Special characters
• Mobile responsiveness

Flaky Test Management

Identify Flaky Tests

# Run test multiple times
npx playwright test --repeat-each=10

# Run with retries
npx playwright test --retries=3

Common Causes & Fixes

Race Conditions

// ❌ FLAKY
await page.click('[data-testid="button"]')

// ✅ STABLE (auto-wait)
await page.locator('[data-testid="button"]').click()

Network Timing

// ❌ FLAKY
await page.waitForTimeout(5000)

// ✅ STABLE
await page.waitForResponse(resp => 
  resp.url().includes('/api/users') && resp.status() === 200
)

Dynamic Content

// ❌ FLAKY
await expect(page.locator('[data-testid="result"]')).toBeVisible()

// ✅ STABLE
await page.locator('[data-testid="result"]').waitFor({ state: 'visible' })
await expect(page.locator('[data-testid="result"]')).toBeVisible()

Quarantine Pattern

// Mark as flaky
test('complex search query', async () => {
  test.fixme(true, 'Flaky - Issue #123')
  // test code
})

// Or skip in CI
test('complex search query', async () => {
  test.skip(process.env.CI, 'Flaky in CI - Issue #123')
  // test code
})

Best Practices

Selectors

• ✅ Use data-testid attributes (stable, semantic)
• ✅ Use semantic roles: page.getByRole('button', { name: 'Submit' })
• ❌ Avoid CSS classes (change with styling)
• ❌ Avoid XPath (brittle)

Test Data

• Use unique data per test (timestamps, UUIDs)
• Reset database state before/after tests
• Use fixtures for reusable test data

Test Independence

• Each test must pass independently
• No shared state between tests
• Clean up in afterEach

Performance

• Keep tests under 30 seconds
• Use parallel execution where safe
• Mock slow external services

CI/CD Integration

GitHub Actions Example

name: E2E Tests

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      
      - uses: actions/setup-node@v3
        with:
          node-version: 18
          
      - name: Install dependencies
        run: npm ci
        
      - name: Install Playwright
        run: npx playwright install --with-deps
        
      - name: Run E2E tests
        run: npx playwright test
        
      - name: Upload artifacts
        if: always()
        uses: actions/upload-artifact@v3
        with:
          name: playwright-report
          path: |
            playwright-report/
            test-results/
          retention-days: 30

Playwright Configuration

// playwright.config.ts
export default defineConfig({
  testDir: './tests/e2e',
  fullyParallel: true,
  forbidOnly: !!process.env.CI,
  retries: process.env.CI ? 2 : 0,
  workers: process.env.CI ? 1 : undefined,
  reporter: [
    ['html'],
    ['junit', { outputFile: 'results.xml' }]
  ],
  use: {
    baseURL: process.env.BASE_URL || 'http://localhost:3000',
    trace: 'on-first-retry',
    screenshot: 'only-on-failure',
    video: 'retain-on-failure',
  },
  projects: [
    { name: 'chromium', use: { ...devices['Desktop Chrome'] } },
    { name: 'firefox', use: { ...devices['Desktop Firefox'] } },
    { name: 'mobile', use: { ...devices['Pixel 5'] } },
  ],
  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:3000',
    reuseExistingServer: !process.env.CI,
  },
})

Artifact Management

Artifact	When to Capture	Configuration
Screenshot	On failure	screenshot: 'only-on-failure'
Video	On failure	video: 'retain-on-failure'
Trace	Always	trace: 'on-first-retry'

View trace: npx playwright show-trace trace.zip

Output Format

## E2E Test Results

**Status:** ❌ FAILING (2 failed, 1 flaky)
**Duration:** 3m 45s

### Summary
| Suite | Total | Passed | Failed | Flaky |
|-------|-------|--------|--------|-------|
| Auth | 5 | 4 | 1 | 0 |
| Markets | 8 | 6 | 1 | 1 |
| Wallet | 3 | 3 | 0 | 0 |

### Failed Tests

#### 1. Auth - Password Reset
**File:** `tests/auth/reset.spec.ts:42`
**Error:** Element not found: [data-testid="reset-email"]
**Screenshot:** test-results/reset-failed.png
**Trace:** test-results/trace.zip

**Steps:**
1. Navigate to /reset-password
2. Fill email
3. Click submit
4. ❌ Element [data-testid="reset-email"] not found

**Fix:** Update selector to match actual element

#### 2. Markets - Search Results
**File:** `tests/markets/search.spec.ts:28`
**Error:** Expected 5 results, got 0
**Issue:** Search API returning empty array

### Flaky Tests

#### 1. Markets - Filter by Category
**File:** `tests/markets/filter.spec.ts:15`
**Flakiness:** 30% (3/10 runs failed)
**Action:** Quarantined - Issue #456

### Next Steps
- [ ] Fix Auth selector issue
- [ ] Investigate Markets search API
- [ ] Address flaky filter test

Commands Reference

# Run tests
npx playwright test

# Run with UI
npx playwright test --ui

# Debug
npx playwright test --debug

# Generate test code
npx playwright codegen http://localhost:3000

# Show report
npx playwright show-report

# Update snapshots
npx playwright test --update-snapshots