Frontend Testing

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• Best Practices

Overview

Build comprehensive test suites for frontend applications including unit tests, integration tests, and end-to-end tests with proper coverage and assertions.

When to Use

• Component testing
• Integration testing
• End-to-end testing
• Regression prevention
• Quality assurance
• Test-driven development

Quick Start

Minimal working example:

// Button.test.tsx
import { render, screen, fireEvent } from '@testing-library/react';
import '@testing-library/jest-dom';
import { Button } from './Button';

describe('Button Component', () => {
  it('renders button with text', () => {
    render(<Button>Click me</Button>);
    expect(screen.getByRole('button')).toHaveTextContent('Click me');
  });

  it('calls onClick handler when clicked', () => {
    const handleClick = jest.fn();
    render(<Button onClick={handleClick}>Click</Button>);

    fireEvent.click(screen.getByRole('button'));
    expect(handleClick).toHaveBeenCalledTimes(1);
  });

  it('disables button when disabled prop is true', () => {
    render(<Button disabled>Click me</Button>);
    expect(screen.getByRole('button')).toBeDisabled();
  });

  it('applies variant styles correctly', () => {
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Guide	Contents
Jest Unit Testing (React)	Jest Unit Testing (React)
React Testing Library Integration Tests	React Testing Library Integration Tests
Vitest for Vue Testing	Vitest for Vue Testing
Cypress E2E Testing	Cypress E2E Testing
Test Coverage Configuration	Test Coverage Configuration

Best Practices

✅ DO

• Follow established patterns and conventions
• Write clean, maintainable code
• Add appropriate documentation
• Test thoroughly before deploying

❌ DON'T

• Skip testing or validation
• Ignore error handling
• Hard-code configuration values