playwright

Playwright E2E Testing

Generate and run Playwright end-to-end tests for web applications.

Prerequisites

npx playwright --version

If not installed:

npm init playwright@latest
# or add to existing project:
npm install -D @playwright/test && npx playwright install

Workflow

1. Analyze

Read the source files for the page/component to test. Understand routes, interactive elements, and expected behaviors.

2. Generate Test File

Create a test file following the project's existing patterns and directory structure.

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

test.describe('Feature Name', () => {
  test.beforeEach(async ({ page }) => {
    // Setup: navigate, authenticate, seed data
  });

  test('should do expected behavior', async ({ page }) => {
    // Arrange
    // Act
    // Assert
  });
});

3. Run Tests

npx playwright test <file>           # Run specific test file
npx playwright test --headed          # With visible browser
npx playwright test --ui              # Playwright UI mode
npx playwright test --trace on        # Capture trace for debugging

4. Debug Failures

• Read error output carefully
• Use --trace on and open trace viewer: npx playwright show-trace trace.zip
• Take screenshots on failure: await page.screenshot({ path: 'debug.png' })
• Use page.pause() for step-by-step debugging in headed mode

Capabilities

• Navigation: page.goto(), URL assertions, redirect verification
• Forms: page.fill(), page.selectOption(), page.check(), multi-step wizards
• Assertions: expect(page).toHaveURL(), expect(locator).toBeVisible(), toHaveText()
• Screenshots: page.screenshot(), full-page, element-level
• Visual regression: expect(page).toHaveScreenshot() with thresholds
• Accessibility: @axe-core/playwright, ARIA role selectors, keyboard navigation
• Network: page.route() for mocking, page.waitForResponse() for API calls

Tips

• Use data-testid attributes for stable selectors
• Prefer user-visible text and ARIA roles over CSS selectors
• Use test.step() for complex multi-step flows
• Set baseURL in playwright.config.ts
• Use page.waitForResponse() for async navigation
• Place test files alongside existing test patterns in the project