Testing E2e Playwright Recommended

# Install Playwright
npm init playwright@latest

# This will create:
# - playwright.config.ts
# - tests/ directory
# - tests-examples/ directory

import { defineConfig, devices } from '@playwright/test'

export default defineConfig({
  testDir: './e2e',
  fullyParallel: true,
  forbidOnly: !!process.env.CI,
  retries: process.env.CI ? 2 : 0,
  workers: process.env.CI ? 1 : undefined,
  reporter: 'html',

  use: {
    // Base URL for navigation
    baseURL: 'http://localhost:5173',
    // Capture trace on first retry
    trace: 'on-first-retry',
    // Screenshot on failure
    screenshot: 'only-on-failure',
  },

  projects: [
    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
    },
    {
      name: 'firefox',
      use: { ...devices['Desktop Firefox'] },
    },
    {
      name: 'webkit',
      use: { ...devices['Desktop Safari'] },
    },
    // Mobile viewports
    {
      name: 'Mobile Chrome',
      use: { ...devices['Pixel 5'] },
    },
  ],

  // Run local dev server before tests
  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:5173',
    reuseExistingServer: !process.env.CI,
  },
})

// e2e/user-flow.spec.ts
import { test, expect } from '@playwright/test'

test.describe('User Authentication', () => {
  test('user can log in and see dashboard', async ({ page }) => {
    // Navigate to login
    await page.goto('/login')

    // Fill login form
    await page.getByLabel('Email').fill('user@example.com')
    await page.getByLabel('Password').fill('password123')
    await page.getByRole('button', { name: 'Sign In' }).click()

    // Verify redirect to dashboard
    await expect(page).toHaveURL('/dashboard')
    await expect(page.getByRole('heading', { name: 'Welcome' })).toBeVisible()
  })

  test('shows error for invalid credentials', async ({ page }) => {
    await page.goto('/login')

    await page.getByLabel('Email').fill('wrong@example.com')
    await page.getByLabel('Password').fill('wrongpassword')
    await page.getByRole('button', { name: 'Sign In' }).click()

    await expect(page.getByRole('alert')).toContainText('Invalid credentials')
    await expect(page).toHaveURL('/login')
  })
})

// e2e/product-list.spec.ts
import { test, expect } from '@playwright/test'

test('user can add product to cart', async ({ page }) => {
  await page.goto('/products')

  // Use data-testid for reliable selectors
  await page.getByTestId('product-card').first().click()

  // Verify product detail page
  await expect(page.getByTestId('product-title')).toBeVisible()

  // Add to cart
  await page.getByTestId('add-to-cart-button').click()

  // Verify cart updated
  await expect(page.getByTestId('cart-count')).toHaveText('1')
})

// e2e/pages/LoginPage.ts
import { Page, Locator } from '@playwright/test'

export class LoginPage {
  readonly page: Page
  readonly emailInput: Locator
  readonly passwordInput: Locator
  readonly submitButton: Locator
  readonly errorMessage: Locator

  constructor(page: Page) {
    this.page = page
    this.emailInput = page.getByLabel('Email')
    this.passwordInput = page.getByLabel('Password')
    this.submitButton = page.getByRole('button', { name: 'Sign In' })
    this.errorMessage = page.getByRole('alert')
  }

  async goto() {
    await this.page.goto('/login')
  }

  async login(email: string, password: string) {
    await this.emailInput.fill(email)
    await this.passwordInput.fill(password)
    await this.submitButton.click()
  }
}

// e2e/auth.spec.ts
import { test, expect } from '@playwright/test'
import { LoginPage } from './pages/LoginPage'

test('successful login', async ({ page }) => {
  const loginPage = new LoginPage(page)
  await loginPage.goto()
  await loginPage.login('user@example.com', 'password123')

  await expect(page).toHaveURL('/dashboard')
})

test('homepage visual regression', async ({ page }) => {
  await page.goto('/')

  // Full page screenshot comparison
  await expect(page).toHaveScreenshot('homepage.png')

  // Element-specific screenshot
  await expect(page.getByTestId('hero-section')).toHaveScreenshot('hero.png')
})

# Run all tests
npx playwright test

# Run in headed mode (see browser)
npx playwright test --headed

# Run specific file
npx playwright test e2e/auth.spec.ts

# Run in specific browser
npx playwright test --project=chromium

# Debug mode
npx playwright test --debug

# Generate test from actions
npx playwright codegen localhost:5173