Playwright E2e Tester Agent Skill

Playwright E2E Tester

Overview

Expert in end-to-end testing with Playwright, the modern cross-browser testing framework. Specializes in test generation, page object patterns, visual regression testing, and CI/CD integration. Handles complex testing scenarios including authentication flows, API mocking, and mobile emulation.

When to Use

• Setting up Playwright in a new or existing project
• Writing E2E tests for critical user flows
• Debugging flaky tests or test failures
• Implementing visual regression testing
• Configuring Playwright for CI/CD pipelines
• Migrating from Cypress, Selenium, or Puppeteer
• Testing authenticated flows with session management
• Cross-browser testing (Chromium, Firefox, WebKit)

Capabilities

Test Generation & Writing

• Generate Playwright tests from user stories or acceptance criteria
• Write tests using best practices (locators, assertions, waits)
• Implement Page Object Model (POM) patterns
• Create reusable test fixtures and utilities
• Handle dynamic content and race conditions

Configuration & Setup

• Configure playwright.config.ts for different environments
• Set up projects for multiple browsers and viewports
• Configure base URL, timeouts, and retries
• Implement global setup/teardown for auth
• Set up test reporters (HTML, JSON, JUnit)

Advanced Patterns

• API mocking with route() and fulfill()
• Network interception and request validation
• Visual regression with toHaveScreenshot()
• Accessibility testing with @axe-core/playwright
• Mobile emulation and device testing
• Geolocation and permissions mocking

CI/CD Integration

• GitHub Actions workflow configuration
• Parallel test execution with sharding
• Artifact collection (traces, screenshots, videos)
• Flaky test detection and retry strategies
• Test result reporting and notifications

Debugging & Maintenance

• Use Playwright Inspector and Trace Viewer
• Debug with page.pause() and headed mode
• Analyze test traces for failures
• Reduce test flakiness with proper waits
• Maintain test stability over time

Dependencies

Works well with:

• vitest-testing-patterns - Unit test patterns that complement E2E
• github-actions-pipeline-builder - CI/CD pipeline setup
• accessibility-auditor - Extended accessibility testing
• api-architect - API contract testing alongside E2E

Examples

Basic Test Structure

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

test.describe('User Authentication', () => {
  test('should allow user to sign in', async ({ page }) => {
    await page.goto('/login');

    await page.getByLabel('Email').fill('[email protected]');
    await page.getByLabel('Password').fill('securepassword');
    await page.getByRole('button', { name: 'Sign In' }).click();

    await expect(page.getByRole('heading', { name: 'Dashboard' })).toBeVisible();
    await expect(page).toHaveURL('/dashboard');
  });
});

Page Object Pattern

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

export class LoginPage {
  readonly page: Page;
  readonly emailInput: Locator;
  readonly passwordInput: Locator;
  readonly signInButton: Locator;

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

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

  async signIn(email: string, password: string) {
    await this.emailInput.fill(email);
    await this.passwordInput.fill(password);
    await this.signInButton.click();
  }
}

Auth Setup Fixture

// fixtures/auth.ts
import { test as base } from '@playwright/test';

export const test = base.extend({
  authenticatedPage: async ({ page }, use) => {
    // Perform authentication
    await page.goto('/login');
    await page.getByLabel('Email').fill(process.env.TEST_USER!);
    await page.getByLabel('Password').fill(process.env.TEST_PASS!);
    await page.getByRole('button', { name: 'Sign In' }).click();

    // Wait for auth to complete
    await page.waitForURL('/dashboard');

    // Use the authenticated page in tests
    await use(page);
  },
});

GitHub Actions CI

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: 20

      - name: Install dependencies
        run: npm ci

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

      - name: Run E2E tests
        run: npx playwright test

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

Visual Regression Test

test('homepage matches snapshot', async ({ page }) => {
  await page.goto('/');

  // Full page screenshot comparison
  await expect(page).toHaveScreenshot('homepage.png', {
    fullPage: true,
    maxDiffPixelRatio: 0.01,
  });

  // Component-level screenshot
  const hero = page.getByTestId('hero-section');
  await expect(hero).toHaveScreenshot('hero-section.png');
});

API Mocking

test('displays products from API', async ({ page }) => {
  // Mock the API response
  await page.route('**/api/products', async (route) => {
    await route.fulfill({
      status: 200,
      contentType: 'application/json',
      body: JSON.stringify([
        { id: 1, name: 'Product A', price: 29.99 },
        { id: 2, name: 'Product B', price: 49.99 },
      ]),
    });
  });

  await page.goto('/products');

  await expect(page.getByText('Product A')).toBeVisible();
  await expect(page.getByText('$29.99')).toBeVisible();
});

Best Practices

• Use role-based locators - Prefer getByRole(), getByLabel(), getByText() over CSS selectors
• Avoid hard waits - Use waitForSelector(), waitForURL(), or assertions instead of waitForTimeout()
• Isolate tests - Each test should be independent and not rely on state from other tests
• Use fixtures - Share setup logic through fixtures rather than beforeEach hooks
• Keep tests focused - Test one user flow per test, avoid testing multiple unrelated things
• Handle flakiness proactively - Use proper waits, retries, and stable locators
• Organize with Page Objects - Encapsulate page interactions for maintainability
• Run in CI - Always run E2E tests in CI before merging

Common Pitfalls

• Flaky locators: Avoid fragile selectors like nth-child(3) or auto-generated class names
• Race conditions: Always wait for elements/navigation before interacting
• Shared state: Tests should not depend on execution order
• Slow tests: Use API calls to set up state instead of UI interactions when possible
• Missing cleanup: Clean up test data to avoid pollution between runs