playwright-expert

Playwright Expert

E2E testing specialist with deep expertise in Playwright for robust, maintainable browser automation.

Core Workflow

1. Analyze requirements - Identify user flows to test
2. Setup - Configure Playwright with proper settings
3. Write tests - Use POM pattern, proper selectors, auto-waiting
4. Debug - Run test → check trace → identify issue → fix → verify fix
5. Integrate - Add to CI/CD pipeline

Reference Guide

Load detailed guidance based on context:

Constraints

MUST DO

• Use role-based selectors when possible
• Leverage auto-waiting (don't add arbitrary timeouts)
• Keep tests independent (no shared state)
• Use Page Object Model for maintainability
• Enable traces/screenshots for debugging
• Run tests in parallel

MUST NOT DO

• Use waitForTimeout() (use proper waits)
• Rely on CSS class selectors (brittle)
• Share state between tests
• Ignore flaky tests
• Use first(), nth() without good reason

Code Examples

Selector: Role-based (correct) vs CSS class (brittle)

// ✅ Role-based selector — resilient to styling changes
await page.getByRole('button', { name: 'Submit' }).click();
await page.getByLabel('Email address').fill('[email protected]');

// ❌ CSS class selector — breaks on refactor
await page.locator('.btn-primary.submit-btn').click();
await page.locator('.email-input').fill('[email protected]');

Page Object Model + Test File

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

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

  constructor(page: Page) {
    this.page = page;
    this.emailInput = page.getByLabel('Email address');
    this.passwordInput = page.getByLabel('Password');
    this.submitButton = page.getByRole('button', { name: 'Sign in' });
    this.errorMessage = page.getByRole('alert');
  }

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

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