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Azu Patrick
Azu Patrick

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🧪 End-to-End Testing Best Practices for Modern QA Engineers

#testing #playwright #cypress #appium

As modern web and mobile apps grow more complex, End-to-End (E2E) testing is critical to ensure seamless user experiences. Having worked across multiple QA stacks using tools like Cypress, Playwright, Appium, and CI/CD pipelines, I’ve compiled essential best practices that every QA engineer should apply in E2E automation.

🧰 1. Choose the Right Tool for the Job

Cypress: Great for modern web apps (React, Vue, Angular).

Playwright: Powerful cross-browser support and API testing.

Appium: Best for mobile (iOS + Android) automation.

TestCafe: Lightweight with automatic waits.

Selenium: Still reliable for legacy apps.

🔗 Example:

npm install cypress --save-dev

// cypress/e2e/login.cy.js
describe('Login Test', () => {
  it('logs in successfully', () => {
    cy.visit('/login');
    cy.get('input[name=email]').type('test@example.com');
    cy.get('input[name=password]').type('securePass123!');
    cy.get('button[type=submit]').click();
    cy.url().should('include', '/dashboard');
  });
});
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🧱 2. Use the Page Object Model (POM)

POM improves maintainability and reduces duplication.

🔗 Example:

// pages/LoginPage.js
class LoginPage {
  visit() { cy.visit('/login'); }
  fillEmail(email) { cy.get('input[name=email]').type(email); }
  fillPassword(password) { cy.get('input[name=password]').type(password); }
  submit() { cy.get('button[type=submit]').click(); }
}

export default new LoginPage();
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// e2e/loginTest.cy.js
import LoginPage from '../pages/LoginPage';

describe('Login Test', () => {
  it('logs in using POM', () => {
    LoginPage.visit();
    LoginPage.fillEmail('test@example.com');
    LoginPage.fillPassword('123456');
    LoginPage.submit();
    cy.url().should('include', '/dashboard');
  });
});
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🔁 3. Integrate with CI/CD Early

Use GitHub Actions, CircleCI, or Jenkins to run tests automatically on pushes or PRs.

🔗 GitHub Actions example:

name: CI

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  cypress-run:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Install deps
        run: npm ci
      - name: Run Cypress Tests
        uses: cypress-io/github-action@v6
        with:
          start: npm start
          wait-on: 'http://localhost:3000'
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✅ Bonus: Add a status badge to your README:

![CI](https://github.com/yourname/yourrepo/actions/workflows/ci.yml/badge.svg)
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👁️ 4. Make Tests Deterministic

  • Avoid flaky tests by:
  • Waiting for network calls to complete.
  • Avoiding hard wait() calls.
  • Using assertions properly (should, expect).

📦 5. Create Reusable Test Data

Use libraries like faker.js

🔗 Example:

import { faker } from '@faker-js/faker';

const user = {
  email: faker.internet.email(),
  name: faker.name.fullName(),
  password: faker.internet.password()
};
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✅ Check my own package:
qa-faker-factory – A simple test data factory for E2E testing.

📊 6. Add Test Management

Use tools like Qase.io, TestRail, or Xray to manage test cases.

  • Link manual test cases with automated ones.
  • Get test coverage reporting.
  • Track test history and failures.

🎯 7. Focus on Critical User Journeys

E2E tests are slow.
Prioritize:

  • Signups / logins
  • Checkout flows
  • Forms
  • Navigation between pages
  • API integrations

🧼 8. Clean up After Each Test

  • Use beforeEach, afterEach properly.
  • Reset states or DBs.
  • Avoid test pollution.

🧩 9. Use Tags for Parallelization and Grouping

Split tests by priority or feature.

// Use tags for filtering
describe('[@smoke]', () => { ... });
describe('[@regression]', () => { ... });
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✨ 10. Track Metrics

  • Track test pass rate, coverage, and flakiness over time using:
  • Allure reports
  • Cypress Dashboard
  • Playwright trace viewer
  • Custom dashboards

📚 Conclusion

As QA engineers, our goal is to ship fast with confidence. Using E2E best practices helps prevent regressions, deliver better UX, and catch issues before they hit production.

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