Webapp Testing

Webapp Testing with Playwright

Purpose

Test local web applications using Playwright for:

• UI verification and visual regression
• User flow testing
• Accessibility compliance
• Cross-browser compatibility
• Debug UI behavior with screenshots/traces

FrankX Project Setup

The project already has Playwright configured:

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

export default defineConfig({
  testDir: './tests/e2e',
  fullyParallel: true,
  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:3000',
    reuseExistingServer: !process.env.CI,
  },
  use: {
    baseURL: 'http://localhost:3000',
    trace: 'on-first-retry',
    screenshot: 'only-on-failure',
  },
});

Test Structure

tests/
├── e2e/
│   ├── homepage.spec.ts      # Landing page tests
│   ├── navigation.spec.ts    # Nav/routing tests
│   ├── blog.spec.ts          # Blog functionality
│   ├── products.spec.ts      # Product pages
│   └── forms.spec.ts         # Form submissions

Core Patterns

Page Object Model

// tests/pages/HomePage.ts
export class HomePage {
  constructor(private page: Page) {}

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

  async getHeroTitle() {
    return this.page.locator('h1').first().textContent();
  }

  async clickCTA() {
    await this.page.getByRole('button', { name: /get started/i }).click();
  }

  async subscribeToNewsletter(email: string) {
    await this.page.getByPlaceholder(/email/i).fill(email);
    await this.page.getByRole('button', { name: /subscribe/i }).click();
  }
}

Basic Test Structure

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

test.describe('Homepage', () => {
  let homePage: HomePage;

  test.beforeEach(async ({ page }) => {
    homePage = new HomePage(page);
    await homePage.goto();
  });

  test('should display hero section', async ({ page }) => {
    const title = await homePage.getHeroTitle();
    expect(title).toContain('FrankX');
  });

  test('should navigate to products on CTA click', async ({ page }) => {
    await homePage.clickCTA();
    await expect(page).toHaveURL(/products/);
  });
});

Form Testing

test('should submit contact form', async ({ page }) => {
  await page.goto('/contact');

  // Fill form
  await page.getByLabel('Name').fill('Test User');
  await page.getByLabel('Email').fill('test@example.com');
  await page.getByLabel('Message').fill('Test message');

  // Submit
  await page.getByRole('button', { name: /send/i }).click();

  // Verify success
  await expect(page.getByText(/thank you/i)).toBeVisible();
});

API Mocking

test('should display products from API', async ({ page }) => {
  // Mock API response
  await page.route('/api/products', async route => {
    await route.fulfill({
      status: 200,
      contentType: 'application/json',
      body: JSON.stringify([
        { id: 1, name: 'Product 1', price: 99 },
        { id: 2, name: 'Product 2', price: 149 },
      ]),
    });
  });

  await page.goto('/products');

  await expect(page.getByText('Product 1')).toBeVisible();
  await expect(page.getByText('Product 2')).toBeVisible();
});

Visual Regression Testing

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

  // Screenshot comparison
  await expect(page.locator('.hero-section')).toHaveScreenshot('hero.png', {
    maxDiffPixels: 100,
  });
});

Accessibility Testing

import { test, expect } from '@playwright/test';
import AxeBuilder from '@axe-core/playwright';

test('should pass accessibility checks', async ({ page }) => {
  await page.goto('/');

  const results = await new AxeBuilder({ page })
    .withTags(['wcag2a', 'wcag2aa'])
    .analyze();

  expect(results.violations).toEqual([]);
});

Debugging Techniques

Screenshots on Failure

test.afterEach(async ({ page }, testInfo) => {
  if (testInfo.status !== 'passed') {
    await page.screenshot({
      path: `screenshots/${testInfo.title}-failure.png`,
      fullPage: true,
    });
  }
});

Trace Viewer

# Run with trace
npx playwright test --trace on

# View trace
npx playwright show-trace trace.zip

Debug Mode

# Headed mode with slowMo
npx playwright test --headed --slowmo=500

# Debug specific test
npx playwright test homepage.spec.ts --debug

# UI mode
npx playwright test --ui

Console Logging

test('debug console logs', async ({ page }) => {
  page.on('console', msg => {
    console.log(`Browser: ${msg.type()}: ${msg.text()}`);
  });

  await page.goto('/');
});

Commands

# Run all e2e tests
npm run test:e2e

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

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

# Update snapshots
npx playwright test --update-snapshots

# Generate test from recording
npx playwright codegen localhost:3000

# Show last HTML report
npx playwright show-report

Best Practices

1. Use semantic locators

   // Good - semantic
   page.getByRole('button', { name: 'Submit' })
   page.getByLabel('Email')
   page.getByText('Welcome')
   
   // Avoid - fragile
   page.locator('.btn-primary')
   page.locator('#email-input')
   

2. Wait for network idle

   await page.goto('/', { waitUntil: 'networkidle' });
   

3. Use test isolation

   test.describe.configure({ mode: 'parallel' });
   

4. Clean state between tests

   test.beforeEach(async ({ context }) => {
     await context.clearCookies();
   });
   

FrankX-Specific Tests

PDF Download Flow

test('should download PDF guide', async ({ page }) => {
  await page.goto('/guides');

  const [download] = await Promise.all([
    page.waitForEvent('download'),
    page.click('text=Download PDF'),
  ]);

  expect(download.suggestedFilename()).toMatch(/\.pdf$/);
});

Newsletter Signup

test('newsletter signup flow', async ({ page }) => {
  await page.goto('/');

  await page.fill('[data-testid="email-input"]', 'test@example.com');
  await page.click('[data-testid="subscribe-btn"]');

  await expect(page.getByText(/check your inbox/i)).toBeVisible();
});

When to Use This Skill

• Writing new e2e tests
• Debugging UI issues
• Verifying user flows
• Testing responsive design
• Accessibility auditing

Related Skills

• test-driven-development - TDD principles apply to e2e
• systematic-debugging - Debug failing tests
• shadcn-ui-patterns - Component patterns to test

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