End-to-End Testing Case Studies

Introduction

End-to-end (E2E) testing is a crucial part of the software testing lifecycle. It ensures that the entire application flow, from start to finish, works as expected. In this lesson, we will explore two comprehensive case studies using Cypress and Playwright for E2E testing.

Case Study 1: E-commerce Application

Overview

The e-commerce application allows users to browse products, add them to a cart, and make purchases. We will demonstrate how E2E testing can ensure these functionalities work seamlessly.

Test Scenario

Verify that a user can successfully add a product to their cart and complete a purchase.

Cypress Code Example


describe('E-commerce Application E2E Tests', () => {
    it('should allow a user to add a product to the cart and complete a purchase', () => {
        cy.visit('https://ecommerce.example.com');
        cy.get('.product').first().click();
        cy.get('.add-to-cart').click();
        cy.get('.cart').click();
        cy.get('.checkout').click();
        cy.get('#payment-info').type('4111111111111111'); // Test Card Number
        cy.get('.submit-order').click();
        cy.contains('Order Confirmation').should('be.visible');
    });
});

Case Study 2: Banking Application

Overview

This case study covers a banking application where users can log in, check their balance, and transfer money. E2E testing will ensure that these functions work correctly.

Test Scenario

Verify that a user can log in, check their balance, and perform a fund transfer.

Playwright Code Example


const { test, expect } = require('@playwright/test');

test('Banking Application E2E Test', async ({ page }) => {
    await page.goto('https://banking.example.com');
    await page.fill('#username', 'testuser');
    await page.fill('#password', 'password123');
    await page.click('#login');
    await expect(page).toHaveURL('https://banking.example.com/dashboard');
    
    await page.click('#check-balance');
    await expect(page.locator('.balance')).toContainText('$1000');
    
    await page.fill('#transfer-amount', '100');
    await page.click('#transfer-button');
    await expect(page.locator('.transfer-status')).toContainText('Transfer Successful');
});

Best Practices for End-to-End Testing

Use descriptive test names to clarify the purpose of each test.
Keep tests independent to avoid cascading failures.
Utilize fixtures and mock data to speed up tests.
Run tests in parallel to reduce execution time.
Regularly review and refactor tests for clarity and maintainability.

FAQ

What is end-to-end testing?

End-to-end testing is a testing methodology that verifies the complete workflow of an application from the user's perspective.

Why should I use Cypress or Playwright for E2E testing?

Cypress and Playwright provide powerful APIs for web testing, allowing for easy automation of user interactions and assertions.

How do I choose between Cypress and Playwright?

Choose Cypress for its user-friendly interface and robust debugging tools, while Playwright is excellent for cross-browser testing capabilities.