Playwright Testing

# Playwright E2E Testing Skill


For end-to-end testing of web applications with Playwright - cross-browser, fast, reliable.

**Sources:** [Playwright Best Practices](https://playwright.dev/docs/best-practices) | [Playwright Docs](https://playwright.dev/docs/intro) | [Better Stack Guide](https://betterstack.com/community/guides/testing/playwright-best-practices/)

---

## Setup

### Installation

```bash
# New project
npm init playwright@latest

# Existing project
npm install -D @playwright/test
npx playwright install
```

### Configuration

```typescript
// playwright.config.ts
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'],
    ['list'],
    process.env.CI ? ['github'] : ['line'],
  ],

  use: {
    baseURL: process.env.BASE_URL || 'http://localhost:3000',
    trace: 'on-first-retry',
    screenshot: 'only-on-failure',
    video: 'retain-on-failure',
  },

  projects: [
    // Auth setup - runs once before all tests
    { name: 'setup', testMatch: /.*\.setup\.ts/ },

    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
      dependencies: ['setup'],
    },
    {
      name: 'firefox',
      use: { ...devices['Desktop Firefox'] },
      dependencies: ['setup'],
    },
    {
      name: 'webkit',
      use: { ...devices['Desktop Safari'] },
      dependencies: ['setup'],
    },
    // Mobile viewports
    {
      name: 'mobile-chrome',
      use: { ...devices['Pixel 5'] },
      dependencies: ['setup'],
    },
    {
      name: 'mobile-safari',
      use: { ...devices['iPhone 12'] },
      dependencies: ['setup'],
    },
  ],

  // Start dev server before tests
  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:3000',
    reuseExistingServer: !process.env.CI,
    timeout: 120 * 1000,
  },
});
```

---

## Project Structure

```
project/
├── e2e/
│   ├── fixtures/
│   │   ├── auth.fixture.ts      # Auth fixtures
│   │   └── test.fixture.ts      # Extended test with fixtures
│   ├── pages/
│   │   ├── base.page.ts         # Base page object
│   │   ├── login.page.ts        # Login page object
│   │   ├── dashboard.page.ts    # Dashboard page object
│   │   └── index.ts             # Export all pages
│   ├── tests/
│   │   ├── auth.spec.ts         # Auth tests
│   │   ├── dashboard.spec.ts    # Dashboard tests
│   │   └── checkout.spec.ts     # Checkout flow tests
│   ├── utils/
│   │   ├── helpers.ts           # Test helpers
│   │   └── test-data.ts         # Test data factories
│   └── auth.setup.ts            # Global auth setup
├── playwright.config.ts
└── .auth/                        # Stored auth state (gitignored)
```

---

## Locator Strategy (Priority Order)

Use locators that mirror how users interact with the page:

```typescript
// ✅ BEST: Role-based (accessible, resilient)
page.getByRole('button', { name: 'Submit' })
page.getByRole('textbox', { name: 'Email' })
page.getByRole('link', { name: 'Sign up' })
page.getByRole('heading', { name: 'Welcome' })

// ✅ GOOD: User-facing text
page.getByLabel('Email address')
page.getByPlaceholder('Enter your email')
page.getByText('Welcome back')
page.getByTitle('Profile settings')

// ✅ GOOD: Test IDs (stable, explicit)
page.getByTestId('submit-button')
page.getByTestId('user-avatar')

// ⚠️ AVOID: CSS selectors (brittle)
page.locator('.btn-primary')
page.locator('#submit')

// ❌ NEVER: XPath (extremely brittle)
page.locator('//div[@class="container"]/button[1]')
```

### Chaining Locators

```typescript
// Narrow down to specific se