Playwright Setup Skill

This skill covers Playwright end-to-end testing setup for React applications.

When to Use

Use this skill when:

• Setting up E2E testing
• Configuring cross-browser testing
• Implementing CI/CD testing
• Creating Page Object Models

Core Principle

TEST USER JOURNEYS - E2E tests verify complete user flows. Focus on critical paths that matter to users.

Installation

npm init playwright@latest

Or manually:

npm install -D @playwright/test
npx playwright install

Configuration

// playwright.config.ts
import { defineConfig, devices } from '@playwright/test';

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'],
    ['json', { outputFile: 'test-results/results.json' }],
    ['list'],
  ],
  use: {
    baseURL: 'http://localhost:3000',
    trace: 'on-first-retry',
    screenshot: 'only-on-failure',
    video: 'on-first-retry',
  },
  projects: [
    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
    },
    {
      name: 'firefox',
      use: { ...devices['Desktop Firefox'] },
    },
    {
      name: 'webkit',
      use: { ...devices['Desktop Safari'] },
    },
    {
      name: 'Mobile Chrome',
      use: { ...devices['Pixel 5'] },
    },
    {
      name: 'Mobile Safari',
      use: { ...devices['iPhone 12'] },
    },
  ],
  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:3000',
    reuseExistingServer: !process.env.CI,
    timeout: 120 * 1000,
  },
});

Project Structure

tests/
├── e2e/
│   ├── pages/              # Page Objects
│   │   ├── LoginPage.ts
│   │   ├── DashboardPage.ts
│   │   └── BasePage.ts
│   ├── fixtures/           # Custom fixtures
│   │   └── index.ts
│   ├── auth.spec.ts
│   ├── dashboard.spec.ts
│   └── checkout.spec.ts
└── playwright.config.ts

Basic Test

import { test, expect } from '@playwright/test';

test.describe('Home Page', () => {
  test('displays welcome message', async ({ page }) => {
    await page.goto('/');

    await expect(page.getByRole('heading', { name: 'Welcome' })).toBeVisible();
  });

  test('navigates to about page', async ({ page }) => {
    await page.goto('/');

    await page.getByRole('link', { name: 'About' }).click();

    await expect(page).toHaveURL('/about');
  });
});

Page Object Model

Base Page

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

export class BasePage {
  readonly page: Page;
  readonly header: Locator;
  readonly footer: Locator;

  constructor(page: Page) {
    this.page = page;
    this.header = page.getByRole('banner');
    this.footer = page.getByRole('contentinfo');
  }

  async navigate(path: string): Promise<void> {
    await this.page.goto(path);
  }

  async waitForPageLoad(): Promise<void> {
    await this.page.waitForLoadState('networkidle');
  }
}

Login Page

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

export class LoginPage extends BasePage {
  readonly emailInput: Locator;
  readonly passwordInput: Locator;
  readonly submitButton: Locator;
  readonly errorMessage: Locator;

  constructor(page: Page) {
    super(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(): Promise<void> {
    await this.navigate('/login');
  }

  async login(email: string, password: string): Promise<void> {
    await this.emailInput.fill(email);
    await this.passwordInput.fill(password);
    await this.submitButton.click();
  }

  async expectError(message: string): Promise<void> {
    await expect(this.errorMessage).toContainText(message);
  }

  async expectLoggedIn(): Promise<void> {
    await expect(this.page).toHaveURL('/dashboard');
  }
}

Using Page Objects

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

test.describe('Authentication', () => {
  test('logs in with valid credentials', async ({ page }) => {
    const loginPage = new LoginPage(page);

    await loginPage.goto();
    await loginPage.login('user@example.com', 'password123');
    await loginPage.expectLoggedIn();
  });

  test('shows error with invalid credentials', async ({ page }) => {
    const loginPage = new LoginPage(page);

    await loginPage.goto();
    await loginPage.login('user@example.com', 'wrongpassword');
    await loginPage.expectError('Invalid credentials');
  });
});

Fixtures

// tests/e2e/fixtures/index.ts
import { test as base } from '@playwright/test';
import { LoginPage } from '../pages/LoginPage';
import { DashboardPage } from '../pages/DashboardPage';

interface Pages {
  loginPage: LoginPage;
  dashboardPage: DashboardPage;
}

interface TestFixtures {
  authenticatedPage: void;
}

export const test = base.extend<Pages & TestFixtures>({
  loginPage: async ({ page }, use) => {
    await use(new LoginPage(page));
  },

  dashboardPage: async ({ page }, use) => {
    await use(new DashboardPage(page));
  },

  authenticatedPage: async ({ page }, use) => {
    // Setup: Login before test
    await page.goto('/login');
    await page.getByLabel('Email').fill('test@example.com');
    await page.getByLabel('Password').fill('password123');
    await page.getByRole('button', { name: 'Sign in' }).click();
    await page.waitForURL('/dashboard');

    // Run the test
    await use();

    // Teardown: Logout after test (if needed)
  },
});

export { expect } from '@playwright/test';

// Usage
import { test, expect } from '../fixtures';

test.describe('Dashboard', () => {
  test('shows user info when authenticated', async ({ page, authenticatedPage }) => {
    await expect(page.getByText('Welcome back')).toBeVisible();
  });
});

Authentication State

Saving Auth State

// tests/e2e/auth.setup.ts
import { test as setup, expect } from '@playwright/test';

const authFile = 'tests/.auth/user.json';

setup('authenticate', async ({ page }) => {
  await page.goto('/login');
  await page.getByLabel('Email').fill('test@example.com');
  await page.getByLabel('Password').fill('password123');
  await page.getByRole('button', { name: 'Sign in' }).click();

  await page.waitForURL('/dashboard');

  await page.context().storageState({ path: authFile });
});

Using Auth State

// playwright.config.ts
export default defineConfig({
  projects: [
    { name: 'setup', testMatch: /.*\.setup\.ts/ },
    {
      name: 'chromium',
      use: {
        ...devices['Desktop Chrome'],
        storageState: 'tests/.auth/user.json',
      },
      dependencies: ['setup'],
    },
  ],
});

API Mocking

test('displays mocked data', async ({ page }) => {
  await page.route('**/api/users', async (route) => {
    await route.fulfill({
      status: 200,
      contentType: 'application/json',
      body: JSON.stringify([{ id: 1, name: 'Mock User' }]),
    });
  });

  await page.goto('/users');

  await expect(page.getByText('Mock User')).toBeVisible();
});

Commands

# Run all tests
npx playwright test

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

# Run with UI mode
npx playwright test --ui

# Run in headed mode
npx playwright test --headed

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

# Debug mode
npx playwright test --debug

# Show report
npx playwright show-report

# Update snapshots
npx playwright test --update-snapshots

CI Configuration

# .github/workflows/e2e.yml
name: E2E Tests

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-node@v4
        with:
          node-version: '22'

      - name: Install dependencies
        run: npm ci

      - name: Install Playwright browsers
        run: npx playwright install --with-deps

      - name: Run tests
        run: npx playwright test

      - name: Upload report
        uses: actions/upload-artifact@v4
        if: always()
        with:
          name: playwright-report
          path: playwright-report/

Best Practices

1. Use locators - Prefer role, label, text over CSS selectors
2. Wait for elements - Use auto-waiting, avoid fixed sleeps
3. Independent tests - No test should depend on another
4. Page Object Model - Encapsulate page interactions
5. CI-specific config - Different retries, workers for CI
6. Auth state reuse - Save and restore auth state

Notes

• Playwright auto-waits for elements
• Use --debug to step through tests
• Traces help debug flaky tests
• Run in parallel for speed